Topic: Electrical problem or fuel?

[Duke McDukiedook]

black to common, red to 10ADC, 20 DCV on the selector.
Hook it up and measure away.
Please tell me that's not your Fluke in the pic.

[B.O.X.N.I.F.E.]

No, not my tester. Using those settings it read 0.00 and the wires got REALLY hot REALLY fast! It sparked pretty hard when I touched the tips to the terminal too. Is that def the right setting?

[B.O.X.N.I.F.E.]

So here ya go, note the AUDIO is what you're looking for here. The video is crap, sorry!!

First you'll notice it's idled way up. It won't idle on low rpm. Not sure why. There's a a weird knock in the second video, you'll hear it when the rpms drop.

Voltage after trickle charge was right at 12. Danced around 14 - 14.5 when revved. Strangely, I rode for about an hour, killed it, tried to restart and the battery died within about 15 seconds. Maybe I'm just used to cars and motorcycles batteires drain quicker than Im used to when cranking. Watch the videos and let me know what your guys overall impression is.

[youtube=425,350]http://www.youtube.com/watch?v=-_4QQMDa1_Q[/youtube]http://www.youtube.com/watch?v=-_4QQMDa1_Q

[youtube=425,350]http://www.youtube.com/watch?v=DLqfwbbt8T0[/youtube]http://www.youtube.com/watch?v=DLqfwbbt8T0

[Spanner 1]

Yeaaah !, your charging system seems to be working, but your bike sounds like it's running on 2 and a-half cylinders .....time to take the carbs off and take 'em apart and clean 'em...sorry you paid 75 dollairos for a carb cleaner squirt job.....I wish that worked, we'd all do it !!...anyway, it's not that hard to do, just go to Carb. FAQ's and read...
Also, need to be sure no more rust/crap in tank is ready to flow down to your nice, newly cleaned carbs, or its start over...

[B.O.X.N.I.F.E.]

I felt the headers a few minutes after shut off and they all felt evenly hot, except #1 seemed a little cooler. Could have just been my perception. Anybody have any specific ideas where I should start based on sound of the bike? I just ran a lot of cleaner through the carbs and was hoping that would do it, but I guess that might not be the case.

[Bill Vaughan]

Yeah, running on two and sometimes three cylinders, but definitely not four.  Time to rip apart the carbs.

[gregimotis]

Carbs aren't that hard.  Read the FAQ, read the manual, and keep the bits organized so you can put it back together.

get a toothbrush and/or scotchbrite pad, a can or two of spray carb cleaner (a bucket of dip if you can afford it) and a can of compressed air.


warm up your inner obsessive-compulsive and go-to.  Takes half a day the first time, hour and a half the second.

[750goes]

check the colour/condition of your plugs  - you could have one of them fouled
also check the spark plug leads for any cracks and bad corrosion on the ends
check the plug caps for resistance as well...

and clean them carbs - it will make a lot of difference - I would say at least one or more of the idle jets will be plugged for sure - as it did not want to idle at low revs..

most important is good clean fuel flow from tank to carbs - if this is clean then carbs and electrics are easy fixes to follow as required.

keep at it

[B.O.X.N.I.F.E.]

So it sounds like carbs! When I rebuild should I just get gaskets, or do I need to replace hard parts as part of a regular rebuild?

How do I make sure each cylinder is getting spark?

Fuel delivery is good, I cleaned the tank & petcock within an inch of their lives.

[750goes]

if you are careful, you will not need anything - just strip, clean thoroughly, and rebuild then synch the carbs...

If you feel the need to replace gaskets and or "O" rings when you have them pulled down, then that is the best time to do it. If you are on a budget rebuild - then reuse what you have - just disassemble them carefully, and put everything for each carb in its own little container for not mixing things up....simple...

[TwoTired]

It's not running on all four properly.  Do check the spark plugs for carbon buildup, which may stop a cylinder from firing properly, or simply put in new plugs to determine effect.  You can check for spark by laying a connected plug onto the engine and cranking it over.  Remember that the cylinders spark in pairs.  Both need to be allowed to spark in order to get any spark.

If it won't idle, you likely have some slow jets blocked.  If it is an outer carb (1&4) it is relatively easy to remove the the carb bowls to access and remove the slow jet for cleaning.  2&3 can also be done with the carbs on the bike.  It's just more difficult.
You can also drain and catch what comes out of the carbs bowls for debris inspection.  If you find bits larger in the drainage than 0.016 of an inch, those particles can block slow jets.
I make my carb pulling assessments after an drop and bowl or two.  Nasty scale and junk clinging to the insides are better addressed with the carbs on the bench.  However, if it is just some rust bits that are floating around in the bowls, clearing the slow jets is likely all it needs.

Don't worry about the noise you are hearing at the lowest RPM.  At least not until you get all four firing evenly.  Then you may need a carb sync to make the idle smooth enough to make the lower end quieter.
It should be a good engine after you make sure the the spark is happy and the carbs are working properly.

Cheers,

[B.O.X.N.I.F.E.]

Awesome, thanks guys.

When I was cleaning the tank up I took off the bowl from #1. The inside was very clean, no thick buildup. I put about half a can of carb cleaner through the fuel lines, draining twice. The first time was pretty dark brown with small bits of rust. The second was almost clear.

So I guess first I'll check for spark. I've heard of that method, do I need to pull the two pair of plugs out at the same time and test two at a time? I don't know which cylinders are pairs.

TwoTired, do you work overnight shifts, or are you just a night owl?

[MJL]

You can do one plug at a time. Pairs are 1-4 and 2-3 if it is the same as my 750 and 650. I usually have a spare plug around for testing, that way I don't have to pull one to test. (As long as your plugs are known to be good) Or you can buy a spark tester.

http://images.google.com/images?q=spark%20tester&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wi

[TwoTired]

So I guess first I'll check for spark. I've heard of that method, do I need to pull the two pair of plugs out at the same time and test two at a time? I don't know which cylinders are pairs.

TwoTired, do you work overnight shifts, or are you just a night owl?

Pairs are 1-4 and 2-3.  Looking at spark plug deposits can be a major diagnostic indicator regarding combustion conditions inside the cylinder.  Were I you, I'd pull them all out (the engine spins with far less load on starter and battery), and post an in-focus picture of the tips, keeping the cylinder orientation recorded.  The tip condition can be a pointer, where you can focus future efforts.

I'm retired.  But, I maintain a strict sleeping regimen starting at oh dark thirty, and rising at the crack off eyelids.

Cheers,

[B.O.X.N.I.F.E.]

Here's number 1:



Oily! I stuck a new plug on the boot, threads to engine, and it's getting spark. So is number 4. Getting tools tonight to reach 2 & 3. I put a new plug in #1 and it ran no better. I got home (about 6 miles) and the new plug looked like the old one, very oily.

#1 pipe is def cooler than the other 3.

edit: also, the the head gasket looks to be weeping pretty good on the #1 side. Not sure if the oil might be migrating there from somewhere else.

'nuther edit: I started the bike, idled up to 2k and just pulled the boot off of plug number one. No change at all in sound, so I think that's the culprit cylinder. It's definetly got spark to that cable because my hand got a little too close to the boot and caught some of that blue magic. I had a strong urge to take a wizz shortly after!

[Accolay]

If you're on a budget for stuff and you need a good spark plug wrench, I recommend the one that came with the bike from Honda.    

SKU: 89216-323-000
WRENCH, SPARK PLUG (Honda Code 0254094)

It's only 3.13 on motogrid.com, but then again...bikebandit's OEM checker says you can't order it. Mine was cheap too, but I got it from Hondaparts-direct.com...

[750goes]

that is one ugly spark plug - how does it compare with #4...

I would be doing a valve adjustment on #1, the other 3 cylinders too while you are at it, then a compression test across the cylinders.....let us know the results..

oily, sooty plug possible causes - leaky inlet valve, valve stem seal is compromised, bad rings, or oil scraper ring, worn out rings etc... hopefully not a hole in the cylinder....

[B.O.X.N.I.F.E.]

Ok, it'll take me a couple days to get it done but I'll post up the results. I also thought of rings right away, I hope that isn't it. This engine should have gone 80k more before it needed that (if it was well maintained  ) -  How difficult is it pulling the head/cylinders out of the bike? Can this be done with the case still in the frame?

just looked at the other plugs in the light - very, very sooty. totally black, but not wet.

[750goes]

If the bike has not been run in quite a while - you could also have a stuck ring on the #1 piston - which with further running may loosen up, and hopefully not become a rebuild item.

If the other three plugs are very black & sooty - it means there is too much fuel and not enough air getting in to combust properly... the black is unburnt fuel...

there are several areas of maintenance to be performed to get the right air/fuel ratio for a nice clean burn...

not being rude, but what items of maintenance and what history is there that you know of with regard to this bike, and its previous owners maintenance routines..

[Duke McDukiedook]

A compression wet/dry will tell you if it is your valves or rings, so don't be ready to crack that engine quite yet. Go through the full tune-up as described in the manuals and we'll see where you are after that.

[B.O.X.N.I.F.E.]

Not rude at all, I don't know for sure but I think it would be reasonable to guess the bike sat for a long period based on the amount of rust in the tank and how faded the top of the tank is. I do know that the engine was out of the bike for a period before I got it. The float bowls were clean though with no gunk other than rust particles.

I'll get plug pics & compression test results tonight hopefully. I may need to check back if I need any help with the tuneup.

[TwoTired]

The bike has multiple problems.  Oil on a plug is not a good sign.  Something mechanically wrong with the cylinder, probable cause.  Compression test/leakdown test for further info needed.

The soot on the plug could be:
extended operation with choke applied.
Clogged/restrictive air filter.
Emulsion tube air bleeds clogged.
The carbs have too large jets installed, possibly drilled.  So, don't go by stamped number alone.
The slide needles are in the wrong position.

Cheers,

[B.O.X.N.I.F.E.]

Sounds like the possible problems have already been nailed down, but here's the pics just in case:

You've seen #1...

#2



#3



#4




So I'll do the valve adjustment tomorrow, but I am having trouble finding a compression tester. Harbor Freight had a kit with a 12mm fitting (hard to find!), but the hose length was 24". Wouldn't this distort the results? Anyone have this same tester?

(I'd get the leakdown tester, but don't have access to a compressor. They don't make compressed air cans that would work do they?)

[TwoTired]

So I'll do the valve adjustment tomorrow, but I am having trouble finding a compression tester. Harbor Freight had a kit with a 12mm fitting (hard to find!), but the hose length was 24". Wouldn't this distort the results? Anyone have this same tester?

The hose will distort the actual compression peak numbers, making them lower than actual.  But, what you really need to know is comparative numbers with other cylinders.  All should be withing 10 % of each other.

In the ideal case the engine would be hot.  Pull all the plugs, choke off, throttle wide open,  and then kick it for the highest pressure reading and record.  After all cylinders are done this way.  Put a few drops of oil in each cylinder, just enough to make the rings wet, and repeat the test, recording the "wet" numbers.  If it is a ring issue, the temporary oil seal will increase the wet readings over the dry readings in a very noticeable and significant way.  Don't use a lot of oil. the combustion chamber is only about 15cc.  A tablespoon of oil is about 10cc.  This amount will increase the compression ratio making the wet test significantly higher all on it's own.  A single shot of oil from my oil squirter is all I need.

Cheers,

[B.O.X.N.I.F.E.]

OK peoples, here's some new video, have a listen...

So, I adjusted all the valves. I'm not sure the PO even adjusted them, some were just cranked down all the way. After that I did a wet/dry compression test. Remember that my tester has a 24 inch hose, so the numbers would have been slightly higher with a shorter tester:

Dry:

#1 - 90 
#2 - 120
#3 - 115
#4 - 120

Wet:

#1 - 115
#2 - 130
#3 - 120
#4 - 135

All that being said, it's like a different bike now. Run's so much better, but it looks like #1 has some ring blow by. Opinions/suggestions?