testy

Author Topic: Bike won’t start... please help  (Read 721 times)

0 Members and 1 Guest are viewing this topic.

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Bike won’t start... please help
« on: February 10, 2019, 12:37:12 am »
I have a 1971 Honda  cb500. It won’t start. About 10 months ago I had it serviced by a reputable bike shop to get it running because it was sitting for too long. The bike shop got it running. It ran really well for about a month, then one day it started losing power. Seemed like it was outta gas. I checked the tank, there was gas. The bike would run, but if I let off the throttle, it would die. Frustrated, I let the bike sit for (at least) 7 months). I’m now trying to get my bike back to working condition.
The battery was dead... I replaced it. I drained the gas tank and filled it with usable gas. There was a a huge crack in the intake manifold boot (which I think was the root of the problem.... compression problem?) .... I ordered the part and replaced it.  Now when I try to start the bike, it seems like it WANTS to start, but it just won’t (which it didn’t even seem like it was trying to start before I replaced the intake manifold boot), so that was a good indication for me. I went through the clymers manual... checked for a good spark... the two that I checked seemed good. The bike shop replaced all four spark plugs and spark plug wires. It seems like the compression is good. I think my last resort is to turn to the carburetors.... I’ve never work on the carburetors and I’m a novice when it comes to bikes. I’ve YouTubed some carb repair stuff, and think I might give it a shot.... any thoughts?.... helpful carburetor-fix-it links?.... any other ideas to troubleshoot it? Any help would be greatly appreciated

Offline whizzer

  • Full Member
  • *
  • Posts: 54
  • Be safe
Re: Bike won’t start... please help
« Reply #1 on: February 10, 2019, 06:36:40 am »
Gas and spark needed, of course. After trying to start it, pull all plugs. All should be wet. If not, will it start with spray of starter fluid in air box with air filter removed?  Cleaning carbs is very well documented.  Add in search for clear tube test. You must have removed carbs to replace bad rubber gasket. That's the hard part. If plugs are wet, then check for good spark on all plugs.
72 cb350f
66 cb77 sold
72 Suzuki gt750 given away
59 Vespa given away
06 Whizzer sold

Offline BenelliSEI

  • Hot Shot
  • ***
  • Posts: 377
Re: Bike won’t start... please help
« Reply #2 on: February 10, 2019, 06:53:31 am »
Without disturbing any thing, give the points a very light cleaning. A few strokes with a points file or even a nail board file (cardboard). Bikes that sit seem to varnish up the points....... try it, you might be surprised.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 20,966
Re: Bike won’t start... please help
« Reply #3 on: February 10, 2019, 08:33:17 am »
If you use sand paper or grit boards, be aware these leave particles behind, embedded and standing tall in the soft contacts.  The particles are an insulative material, and thus reduce the current carrying capability of the points.  What contact remains heats up more during use and points burn faster leading to premature replacement.

Only a points file should be used on point contacts, unless you are desperate to have it run now, with further maintenance to be done a short time later.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 20,966
Re: Bike won’t start... please help
« Reply #4 on: February 10, 2019, 08:52:12 am »
For the OP;
First "won't start" is a poor description.  Big difference between starter won't spin the engine, and the engine spins but, the cylinders don't light.
I guess we have to assume the latter.  Since you went with a new battery.

Check your stop-run-stop switch position.

Examine the choke lever.  Up is choke applied for starting, down is run position after starting, and in between keeps it running when cold.  But, you have to hold the throttle open a bit, as there is no fast idle cam.  The computer to keep the mixture and RPM proper during warm up, is normally located about two feet above the seat.  It may have to be trained.

Your window on combustion conditions is the spark plug tips.  Look at them.  If covered with dark soot or the gap is filled with material, spark is shunted away, and light off is compromised.  Also, lay the connected spark plug on the motor and look at the spark gap when starting.  The plugs fire in pairs 1-4 and 2-3.  For a spark test, the mated pair must be connected.

Check for voltage at the point contacts with crank stopped.  Points open, should find voltage at one contact set.  Points closed, should shut off voltage.

Open bottom drain screws on the carb bowls to verify they are getting gas to all four.

Report your findings if it still won't start.

Engines run on compression, air/fuel and spark.  Must have all three.  If it doesn't run, one or more is missing.  Start eliminating variables, one at a time until it runs.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #5 on: February 13, 2019, 09:49:40 pm »
Here’s the run down (sorry I couldn’t figure out how to  address you guys/and or girls individually...)
I bought a contact point file and dusted those off, points look like they’re getting spark (the 1 and 4 don’t seem like they’re getting AS much spark as the 2 and 3 side but it still had spark), spark plugs looked fine to me- no soot/ dirt, pulled off spark plugs and checked them against the motor- all four spark plugs have spark,  carb open, switch in the “on” position, sprayed some starter fluid in the air box- starts for about 2-4 seconds then dies... finally, opened on the carb bowls.... #4 had gas draining from it, #2 and #3 had NO gas drain from them and the bolt to #1’s bowl was kinda stripped, so I didn’t want to fight it and strip it further (and cause myself more headache if I didn’t have to)... so I left that one alone.... so I’m guessing I’m not getting gas from (at least) carb 2 and 3?.... time to clean the carbs?.... thanks so much for you guys replying! Very much appreciated!!!

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 5,738
  • "Tremendous progress has been made... "
Re: Bike won’t start... please help
« Reply #6 on: February 14, 2019, 03:33:07 am »
First things first.
1. Detach fuellines from petcock and verify by opening and closing petcock quickly if there is flow from both exits.
2. Fuellines for your model should have a length of 18 (for carbs 1 and 2) and 30 cm (for carbs 3 and 4) and an ideal internal ⌀ of 5,5 mm, outside ⌀ is around 10mm. This to prevent kinking. NO extra inline filters because they can cause problems.
3. With the fuellines detached from the petcock, blow some air through the fuellines. Prior to this, drain the floatbowls and remove the drain screws so you will be able to hear if passage is free. Blow very gently, NOT hard.
4. Detach the 4 tubes from the bottom of the carbbowls and verify the pipes as well as the tubes vent freely. 
5. If there's still no flow, tap (gently!) floatbowls with the stub end of a screwdriver. Maybe float valve needle frees itself. You can combine this with flushing by opening and closing the petcock.
6. No result? Remove floatbowl(s) for inspection.
Money is like manure. It's not worth a thing unless it's spread around.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 20,966
Re: Bike won’t start... please help
« Reply #7 on: February 14, 2019, 01:00:41 pm »
The reserve setting on the fuel valve sources from the bottom of the tank.  The ON selection feeds from a stand pipe.

Does fuel get to all carbs if you select reserve?

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #8 on: February 15, 2019, 02:19:20 am »
Put the tank on “reserve”... still only the #4 carb drained gas.
This seems like a stupid question, but I’m gonna ask it anyway... when I switched the tank to reserve, should I have given the throttle a few cranks to get the gas to the carbs? Or does gravity take charge of that? ... anyhow... I opened the throttle 15-20 times. #4 drained to the point where it just tricked out,  then I tried unscrewing #3 and nothing came out, then I went back to unscrew the #4 and it seemed like it refilled without me giving the throttle a few turns and drained again.... Nothing came outta the #2 and 3 carb bowls

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 5,738
  • "Tremendous progress has been made... "
Re: Bike won’t start... please help
« Reply #9 on: February 15, 2019, 02:58:01 am »
Put the tank on “reserve”... still only the #4 carb drained gas.
This seems like a stupid question, but I’m gonna ask it anyway... when I switched the tank to reserve, should I have given the throttle a few cranks to get the gas to the carbs?
No.
Quote
Or does gravity take charge of that?
Yes.
Quote
wing #3 and nothing came out, then I went back to unscrew the #4 and it seemed like it refilled without me giving the throttle a few turns and drained again.... Nothing came outta the #2 and 3 carb bowls
There is not much mystery in this. Either fuellines are kinked or there's dirt obstructing or sticky float valve needles remain closed. Just walk though the steps I posted. It's dead simple.
Money is like manure. It's not worth a thing unless it's spread around.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 20,966
Re: Bike won’t start... please help
« Reply #10 on: February 15, 2019, 08:15:30 am »
Put the tank on “reserve”... still only the #4 carb drained gas.

Check the fuel tap outlets for flow.

This seems like a stupid question, but I’m gonna ask it anyway... when I switched the tank to reserve, should I have given the throttle a few cranks to get the gas to the carbs? Or does gravity take charge of that? ...

Twisting the throttle only opens and closes the carb slides.  There is no fuel pump.  Fuel flows from tank to carbs via gravity if the hoses are clear and the float valves are open in response to low fuel levels inside the carb bowls.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Bodi

  • Old Timer
  • ******
  • Posts: 4,796
Re: Bike won’t start... please help
« Reply #11 on: February 15, 2019, 03:22:51 pm »
You describe not getting fuel to the carbs. If the petcock is working - fuel runs out the tubes when it's open - I think a carb removal and cleaning is your next step. It's a pain in the a$$. Disconnect the throttle cables and fuel feeds, undo the clamps on the carb spacers and intake pipes, pry the stack off the spacers then pull it out. This is the second hardest part of the job (getting it back in is harder).
Get 4 containers - dollar store food savers are excellent, number them 1 to 4.
Remove the float bowls, note that they are different and remember to put them back on the same way.
Have a look at the innards. Shiny and clean = big win. If they are just gummed up, no big problem. If there's serious corrosion consider getting a used (and not corroded) set of carbs.
Remove the float pins (be very very gentle, do not break off the mounting posts!) and floats. All parts removed go in the numbered container for that body, 1-4 left to right facing forward. Remove float valve bodies. remove main jets. Remove emulsion tubes (press down on the bit sticking out with a wood or soft metal tool from inside the venturi with the throttle wide open to lift the slides). remove pilot jets (these may be push-in? Twist-pull with pliers - gently - to remove them if there's no screwdriver slot). remove the adjuster screws: first, turn in gently to where they stop counting how many turns, record that. Then screw all the way out.
Use carb cleaner spray through the fuel inlets to confirm it sprays out in all bodies.
Same with all internal passages - spray from the openings in the throat and confirm the passages are not blocked.
Clean the emulsion tube holes (main emulsion tubes and pilot jet extensions). use thin copper wire to poke through blocked holes.
Clen the float valve bodies using a Q-tip soaked in carb cleaner spun in the opening. Clean the float needles with tissue and carb cleaner. Inspect the tips, they should be smooth tapers. Replace the valve assembly if the needle or seat is damaged, use genuine Honda (Keihin) ones.
Do not disassemble the carb bodies from the rack or mess with the sync adjustments unless you have a really good reason to, reassembly is tricky and a full carb sync will be required either way.
Check that the jets are clean, if you need to clean or unplug some be super gentle and again use copper wire to poke at the orifices, steel will damage the bores.
I would get new seal kits to replace the o-rings and bowl gasket. There was no reason to remove the top caps unless the slides were stuck but if you have new gaskets you may as well put them in. The throttle needles are almost always OK and I would not remove them unless they are damaged somehow. Plus it's not easy and you pretty much need to mess up sync to get them out.
For seals the Keyster kits are OK... you toss out the brass parts though - they are not so great and cause many problems if installed. The keyster carb service kit costs less than the Honda seal kit. But the Honda seal kit includes some stuff Keyster skips - the fuel crossover and nipple O-rings mostly ... but unless you pull the bodies off the rack (see above) you can't change them. The keyster float valves ... I would not use them, had lots of issues with them and it is not fun to have to pull the carbs again to install OEM ones after the cheap ones start leaking.
Reassemble. Put the emulsion tubes and jets back in the bodies they came from. Same with the floats and float needles, if you use new float valves try to keep the needle with the valve body it came with. The floats have to be the right way up, and this can look like the wrong way up. Take pictures as you disassemble them for reference.
Set the float heights. Instructions abound but the shop manual shows how to do this.
Get stuck drain screws loose while the bowls are off. Draining the bowls is vital if you store the bike for an extended time. Clean the bowls well, make sure the overflows and drains are not blocked with sludge. Replace the bowls, if the gaskets look OK just reuse them, replacing them is tricky. Consider getting allen head screws for the bowls, this makes it less impossible to remove them with the carbs in place.
Put the stack back in the bike. Connect fuel lines, turn on fuel. Leave the fuel on for a few minutes then turn it off. Open each drain screw a bit and confirm there's fuel in all four. No? find out why.
Start her up.
Doing a sync and verifying

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #12 on: February 15, 2019, 11:38:44 pm »
. Detach the 4 tubes from the bottom of the carbbowls and verify the pipes as well as the tubes vent freely. 

Sorry deltarider, I don’t understand this step. Which is the pipe and which is the tube? I’m going off this Clymers manual...

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #13 on: February 15, 2019, 11:50:48 pm »
...BUT....

1. I did detach the lines from the gas tank- gas flow freely from the reserve, had to lift the tank up a little to get it to flow from the main reservoir.
2. Drained the carb bowls from all (except #1)
3. Blew air through the fuel lines...
- 3 and 4 air flowed through the drain screws
- #2... couldn’t get air to pass through. Gently tapped on float chamber body...bingo... air flowed through

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 5,738
  • "Tremendous progress has been made... "
Re: Bike won’t start... please help
« Reply #14 on: February 16, 2019, 01:24:31 am »
Forget about that manual. We do the simple things first. Go with your hand under the four carbs and it will meet 4 black rubber tubes that are attached to little brass pipes that are under the floatbowls. You can detach them and then verify they all 4 vent to the open. To test the little brass pipes are still open, attach some tube that you may have to the little brass pipe and by blowing you can check it's open. Repeat that on all four. Blow gently!
Money is like manure. It's not worth a thing unless it's spread around.

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #15 on: February 16, 2019, 03:38:28 am »
Are these “little brass tubes” threaded? I don’t see how to pull them off.... take plyers to them and pull down?

Online robvangulik

  • Honda Fourever
  • Expert
  • ****
  • Posts: 772
Re: Bike won’t start... please help
« Reply #16 on: February 16, 2019, 04:37:00 am »
Just pull the rubbers tubes off the brass pipes!

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 20,966
Re: Bike won’t start... please help
« Reply #17 on: February 16, 2019, 07:55:15 am »
If you have verified all the carbs have gas in them, check your Stop-Run-Stop switch and try starting again.
...on reserve, since it seems you have a low fuel level in the tank.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #18 on: February 17, 2019, 01:03:22 am »
1. Hooked the brass piping to some tubing... blew (ever-so gently)
2. Reattached the gas lines to the gas tank
3. Put the tank on “reserve”
4. Choke in the “on” position
5. Bike fired up after a few cranks!!!

I had to keep a little pressure applied to the throttle to keep the engine running. When I layed off the throttle, the engine when dead. After about a minute and half my ol lady came out and gave me a.... well a “mouth full” (it’s almost 1am over in  California). So there are a few dogs barking over here (and I’m sure my neighbors are a tad bit annoyed), but I’m having a celebratory beer! I’m hoping that she’s just cold and needs to be started for longer. Excited to see if it starts (and stays started) tomorrow.... I’ll let you guys know.

I CAN’T THANK YOU GUYS/ and or GIRLS ENOUGH!!!!!
... I mean, even if it doesn’t stay started tomorrow, it’s still a HUGE improvement! ... and I’m stoked!!!!

Offline evinrude7

  • just cause i post a lot doesn't mean i'm an
  • Master
  • *****
  • Posts: 1,619
  • something to husker
Re: Bike won’t start... please help
« Reply #19 on: February 17, 2019, 06:56:25 am »
1. Hooked the brass piping to some tubing... blew (ever-so gently)
2. Reattached the gas lines to the gas tank
3. Put the tank on “reserve”
4. Choke in the “on” position
5. Bike fired up after a few cranks!!!

I had to keep a little pressure applied to the throttle to keep the engine running. When I layed off the throttle, the engine when dead. After about a minute and half my ol lady came out and gave me a.... well a “mouth full” (it’s almost 1am over in  California). So there are a few dogs barking over here (and I’m sure my neighbors are a tad bit annoyed), but I’m having a celebratory beer! I’m hoping that she’s just cold and needs to be started for longer. Excited to see if it starts (and stays started) tomorrow.... I’ll let you guys know.

I CAN’T THANK YOU GUYS/ and or GIRLS ENOUGH!!!!!
... I mean, even if it doesn’t stay started tomorrow, it’s still a HUGE improvement! ... and I’m stoked!!!!

been there vulture.  if only the wife, neighbors and dogs knew the heartache you've been through to get to this point they would understand.  i hope that beer tasted fine.
cb750 k6 - ugly

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 5,738
  • "Tremendous progress has been made... "
Re: Bike won’t start... please help
« Reply #20 on: February 17, 2019, 07:07:05 am »
Good. Could well have been the low fuel level that TT already suggested. From now on, I'd follow the instructions on STARTING THE ENGINE Honda layed out on p.28 and 29 of the Owner's Manual*, in particular point 6. on p.29. After a cold start keep the idle higher for some time. Honda suggests 2000 rpm. You can do this, as Honda suggests, by twisting the throttle. Some prefer to do it by turning the big idle adjuster knob, located under the tank RH side. You can close the choke (lever fully down) before you start riding. For models that have the choke operated by the lever at the side of the carbs, it's not advised to start riding with the choke engaged. A raised idle is just what you need for the first few yards. In normal use and warmed up I'd advise to adjust the idle to a true 1100-1200 rpm.
If your bike has been inactive for a long period of time and you finally have it run, consider adding a 'fuel system cleaner' or whatever it is called to the fuel. As long as the jet passages still have some opening, this stuff from a bottle helps to clean them. It also binds moisture. 
* http://www.honda4fun.com/pdf_libretti/500/CB500_k1/CB500_K1_2.pdf
Money is like manure. It's not worth a thing unless it's spread around.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 20,966
Re: Bike won’t start... please help
« Reply #21 on: February 17, 2019, 10:07:46 am »
Some bikes have a fast idle cam coupled to the choke lever, which bumps up the idle speed during choke application.

The US model CB500 and the CB550 through 74 has a knob under the throttle to apply friction to the grip twist.  This can be used to obtain and hold a higher idle speed while the engine warms without holding hand on throttle.  The knob under the bar is easier to reach than the carb throttle stop knob, and you don't have to readjust the carb idle knob again after the engine warms, as it will settle in to it previous warm idle speed once warming is complete.

Once you have the bike sorted, I find no need for a stationary idle period.  The bike can be driven in low performance mode until the engine is warm, with a partial choke application, just enough to allow some acceleration.  Once warm, bump the rest of the choke off.  While riding you can hold the throttle in any position to keep the RPM in a running range.  I suit up for the ride, jump on, apply choke, start , remove some choke and drive off.  Depending on temps the choke gets removes at a stop sign or light a couple blocks latter.  Rest of commute the choke and low throttle position can be ignored to focus on traffic avoidance.  Did this routinely for 20 years on the 74 CB550.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Deltarider

  • Really Old Timer ...
  • *******
  • Posts: 5,738
  • "Tremendous progress has been made... "
Re: Bike won’t start... please help
« Reply #22 on: February 17, 2019, 01:26:20 pm »
Some bikes have a fast idle cam coupled to the choke lever, which bumps up the idle speed during choke application.
Yes, the CB550K3, CB550K4 and the CB550F2 to be precise. NOT the bike in this thread.
Quote
The US model CB500 and the CB550 through 74 has a knob under the throttle to apply friction to the grip twist.  This can be used to obtain and hold a higher idle speed while the engine warms without holding hand on throttle.  The knob under the bar is easier to reach than the carb throttle stop knob, and you don't have to readjust the carb idle knob again after the engine warms, as it will settle in to it previous warm idle speed once warming is complete.
My model happens to have both and I find the one under the bar not easy at all and I wonder what it really was ment for. I know nobody that uses it for what TT describes. It is not even mentioned as such in the Owner's Manuals. To me it is no surprise that the knob under the bar dissappeared on other models. Why not do what Honda suggests? Just keep the throttle twisted inwards a bit. All of the 39 years that I have owned my CB500, I did it either as Honda recommends or used the idle adjust knob.
Quote
Once you have the bike sorted, I find no need for a stationary idle period.
Not that long ago the technicians of the Dutch AA advised even with modern bikes to let them idle for a minute or so after a start.
Quote
The bike can be driven in low performance mode until the engine is warm, with a partial choke application, just enough to allow some acceleration.
  This is not advised by the manufacturer of the bike.
Quote
Once warm, bump the rest of the choke off.
This is not recommended by Honda. Honda designed everything carefully so that the rider can have both hands at the bars at all times. There isn't a single action that requires to take a hand of the bars. Honda was much praised for that. If Honda would have wanted you to play the choke en route, they definitely would have placed the lever in a more convenient location than somewhere down below your thigh, where you have to look for it by groping and run the risk to loose balance and even develop a tank slapper. Moreover, not being able to see the choke lever, you run the risk to forget the choke. Not good for your engine. So to go riding with that chokelever still partially engaged, is bad advice. On the later CB550 models with the fast cam Honda fitted the choke knob at the handlebar, in the line of sight of the rider. I suppose by then Honda had a good reason for this. 
Quote
While riding you can hold the throttle in any position to keep the RPM in a running range.
Yes sir, you are right here and that's what Honda recommends.
Quote
I suit up for the ride, jump on, apply choke, start , remove some choke and drive off.  Depending on temps the choke gets removes at a stop sign or light a couple blocks latter.
 
Quote
Rest of commute the choke and low throttle position can be ignored to focus on traffic avoidance.  Did this routinely for 20 years on the 74 CB550.
I did it my way which is Honda's for 39 years. Sometimes I take the liberty to use the idle adjust screw to raise the idle and then simply screw back that adjuster at the first traffic light that I know will be on my way at forehand. There's no way I'll forget this, the raised rpm will tell me. This in contrast with a still on chokelever which you will not hear and neither is in your line of sight... There's a risk you forget the choke is still on and that you will be washing the oil of the cylinder walls...

Money is like manure. It's not worth a thing unless it's spread around.

Offline vulture0027@gmail.com

  • Full Member
  • *
  • Posts: 57
Re: Bike won’t start... please help
« Reply #23 on: February 18, 2019, 01:53:10 am »
Good. Could well have been the low fuel level that TT already suggested. From now on, I'd follow the instructions on STARTING THE ENGINE Honda layed out on p.28 and 29 of the Owner's Manual*, in particular point 6. on p.29. After a cold start keep the idle higher for some time. Honda suggests 2000 rpm. You can do this, as Honda suggests, by twisting the throttle. Some prefer to do it by turning the big idle adjuster knob, located under the tank RH side. You can close the choke (lever fully down) before you start riding. For models that have the choke operated by the lever at the side of the carbs, it's not advised to start riding with the choke engaged. A raised idle is just what you need for the first few yards. In normal use and warmed up I'd advise to adjust the idle to a true 1100-1200 rpm.
If your bike has been inactive for a long period of time and you finally have it run, consider adding a 'fuel system cleaner' or whatever it is called to the fuel. As long as the jet passages still have some opening, this stuff from a bottle helps to clean them. It also binds moisture. 
* http://www.honda4fun.com/pdf_libretti/500/CB500_k1/CB500_K1_2.pdf

I tried starting it today. It started, but wouldn’t continue to run unless I kept my hand on throttle. I started it with the choke on (up). After about thirty seconds I put the choke down. Kept the rpm at about 1500-2000 for about five minutes. Let off the throttle and the bike would die. Engine was warm to the touch.
.... just to clarify... what I’m hearing  from you is that I need to make an adjustment to the idle, correct?
I’m pretty sure I’ve mentioned that I got the bike back from the shop (around) 8 or 9 months ago and when I got it back the mechanic said “it’s spinning like a top”. So after a month of riding it it started dying on me (my guess is because of the crack in the carb intake boot)....
So I guess my question is: even though he had everything “dialed in” at that point and I only rode the bike for about a month before it took a dump on me, the idle would need to be adjusted in that short of time?
I’m only hesitant to adjust the idle because, well, I’m a COMPLETE NOVICE and I don’t want to screw this up, but if you’re saying that’s what needs to be done to avoid  (yet another) costly trip back to the shop, then that’s what I’ll do.


Online robvangulik

  • Honda Fourever
  • Expert
  • ****
  • Posts: 772
Re: Bike won’t start... please help
« Reply #24 on: February 18, 2019, 02:58:39 am »
Idle adjustment is done in 10 seconds flat, and if you don't like the rezult it can be UNdone in the same amount of time!

 

;
Honda