Topic: Engine not running on 1-2, only on 3-4

[bustech51]

I think we need to get back to basics.  Engines need 3 things to work
1) spark
2) fuel
3) air.
These have to work together to make an engine run.
If you have all 3 then some thing is either broken or out of adjustment. 
What sort of tools are you using and (I hate asking this one generally) what experience do you have.
Tool list:
Test light, multi meter, screw in type compression gauge (nothing fancy) and most importantly a MANUAL.  The manual will show you how to conduct the tests we are talking about. 
As a mechanic I have found myself digging  myself a hole when I don't use the manual.


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[diggidan]

I think we need to get back to basics.  Engines need 3 things to work
1) spark
2) fuel
3) air.
These have to work together to make an engine run.
If you have all 3 then some thing is either broken or out of adjustment. 
What sort of tools are you using and (I hate asking this one generally) what experience do you have.
Tool list:
Test light, multi meter, screw in type compression gauge (nothing fancy) and most importantly a MANUAL.  The manual will show you how to conduct the tests we are talking about. 
As a mechanic I have found myself digging  myself a hole when I don't use the manual.


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Yes you are right.
I have all the tools you list except a screw in comp tester. I only have one with a rubber seal you push against the hole.
I do have a manual. Although I don't really know what to look for in it in a situation like this.

I think I need to get through some of the steps again.

1. Check so through the valve caps so that the valves opens and closes.
2. Drain the float bowls and open the petcock to ensure there is FLOWING fuel when open.
More I don't know.

[Mooshie]

Watching this thread with bated breath.  Dash just started having the exact same thing.  Exhaust 1 & 2 not heating up on pipes at all (minimally) and 3 & 4 perfect.  Checked spark, changing plugs this weekend (they were fouled probably from trying to start him after not doing so for so long), valve clearances all in range now (they were a tad loose), going to change inline fuel filter just because and plug caps are so far out of resistance i am amazed he even started    So ordered new plug caps as well.  I'm thinking carb jets clogged in 1 & 2 but I really do not want to pull the carbs 
Now if only diggidan can figure out what it was on his bike maybe I can stop chasing mine around! 

[diggidan]

---> SOLUTION! <---

Ok, first of all, thank you so much for everyones engagement in my problem. Really appreciate it!

So as I said, I tested with two different carb sets. Both which has run good or ok last summer.
What are the odds BOTH has super clogged jets on 1 and 2. I don't know but in this frickin case they where.
Took all the jets for the carbs and blew them out and the fuel canals, put them back on the bike and the mf started up like nothing had happened.

I feel bad for making you all go through so much trouble trying to help me and then it was a simple thing as this...
But the carbs ran like a month ago so I never thought it would be that...

I'm very grateful for all your help!
Thanks!

Now, lets sync it up and ride!

[Bankerdanny]

Thanks to modern fuel it doesn't take long for carbs to get clogged up. I would be checking the condition of fuel lines to make sure there is not internal deterioration. Ethanol is hell on rubber lines.

[diggidan]

Thanks to modern fuel it doesn't take long for carbs to get clogged up. I would be checking the condition of fuel lines to make sure there is not internal deterioration. Ethanol is hell on rubber lines.

Will do!

[Mooshie]

Darn it.  As I suspected clogged jets. 

[Kenzo1979]

Don’t feel bad.  It’s very common on this forum for people to defend the cleanliness and functionality of their carbs while chasing every other reason for their issue.  Only to reluctantly succumb to pulling, inspecting, cleaning and/or replacing something in the carbs;  I’ve probably done it myself.   In the end — it’s always the freakin’ carbs! 

[Kenzo1979]

Also, seeing things like “snapped camshaft” should make anyone grateful to pull their carbs, LOL.

I am a little confused on how you weren’t seeing a difference with starting fluid.  Did you have the choke on?  Were you pulling the  throttle open at all?

[bustech51]

I know I have fallen into that same hole. It is times like that is when we learn about the various systems on the bike best of all.   Well done for finding the fault and have some awesome rides.  It was warm today but I'm waiting for some good rains to wash the junk off the roads.  Then ill start riding all mine.  I have a 72k, 74(x2) 75F, 77k and 78f (x2).  Fun getting them all going for the year.

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[HondaMan]

Darn it.  As I suspected clogged jets. 

Pilot jets.
They clog with moisture added into the ethanol-laced fuel, unless some oil was also added to the gas: the oil binds with the ethanol and blocks the moisture. This also slows the evaporation from the carbs quite a bit.
I do this with my own, it prevents me having to pull the pilot jets to poke a tiny wire thru them every Spring like I used to in the late 1990s.

[Don R]

  Old guy, old story alert!

I'm the king of changing parts without fixing the problem. K0cb750 812 kit. It would start, then die. I began with plugs and points, progressed to cleaning carbs, changing coils, IV fuel tank, battery, different carbs, different points, hot wired the whole bike, fuel lines, first carbs again, compression test, found a stuck valve, put in a different engine, second set of carbs, more plugs, moved the new points. check valves, Start and die.
 I sat down with a beer and called my brother. I told him I had changed everything except the frame and exhaust pipe. Bingo! Plugged exhaust.   The PO had wrapped fiberglass over the inlet of the baffle.

[bustech51]

Just a quick read from a fuel spec web site.

"According to Dan McTeague, a noted petroleum analyst, Shell and Esso 91 are both ethanol free. All other grades from the companies have some ethanol content, but the mid-grade blend is pure gas, which means it not only corrodes less than ethanol blends, but is less likely to deteriorate when stored."

If at all possible i try to always use Shell fuels in all my bikes.  Some not always possible on longer rides.

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[Mooshie]

wow, that is good to know.  I will keep an eye toward Shell.  I tend to try for Chevron.  Thanks for the tip

[Kenzo1979]

It also helps to know that Esso is the trading name for Exxon/Mobil, So I’m assuming Shell, Exxon and Mobil stations… all of their 91 grade is ethanol free?

[Kenzo1979]

Darn it.  As I suspected clogged jets. 

Pilot jets.
They clog with moisture added into the ethanol-laced fuel, unless some oil was also added to the gas: the oil binds with the ethanol and blocks the moisture. This also slows the evaporation from the carbs quite a bit.
I do this with my own, it prevents me having to pull the pilot jets to poke a tiny wire thru them every Spring like I used to in the late 1990s.

Are you saying you add oil to your gas on every fill up, or before winter storage?  Always looking for a “keep me from getting into the carbs any more than I have to” tip.  What’s your recipe please?..ingredient and measurement.

[scottly]

Just a quick read from a fuel spec web site.

"According to Dan McTeague, a noted petroleum analyst, Shell and Esso 91 are both ethanol free. All other grades from the companies have some ethanol content, but the mid-grade blend is pure gas, which means it not only corrodes less than ethanol blends, but is less likely to deteriorate when stored."

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Around here, 89 octane is the mid-grade blend, and 91 is the highest. There is now a Maverick station nearby with alcohol-free gas, but it is only 87 octane and costs about $.50 more per gallon than 87 with "up to 10% alcohol". If the Shell gas was alcohol free, they would be charging a premium price for it. There is a Shell station 1/2 mile from me; maybe I should test the gas for alcohol content? It's a fairly simple procedure..

[FIREBLADE74]

Similar issue. 1/2 were hot 3/4 were cold. Didn’t make since. Cleaned carbs, set timing, gas tank clean. Lo and behold something told me to pull the tank, mind you I had fuel in the bowls how much I’m not sure cause I only cracked the drain valve. Tank off turn petcock to on, nothing, reserve, only got drips, tilt the tank towards the petcock, no change. So apparently I have blockage at my petcock intermittent cause before I  put the tank I drained the old gas and the petcock worked fine. Gonna pull the petcock sometime this week

[HondaMan]

Darn it.  As I suspected clogged jets. 

Pilot jets.
They clog with moisture added into the ethanol-laced fuel, unless some oil was also added to the gas: the oil binds with the ethanol and blocks the moisture. This also slows the evaporation from the carbs quite a bit.
I do this with my own, it prevents me having to pull the pilot jets to poke a tiny wire thru them every Spring like I used to in the late 1990s.

Are you saying you add oil to your gas on every fill up, or before winter storage?  Always looking for a “keep me from getting into the carbs any more than I have to” tip.  What’s your recipe please?..ingredient and measurement.

Every fillup.
I have a small advantage in that I ride behind a Vetter: it has big side pockets that will carry 2 spare tire tubes, 2 McDonald's large drinks, my large gauntlet riding gloves, 2 windbreakers, some spare sparkplugs and an old plastic bottle labelled "Top Oil" from Bardahl (10 ounces) tht has survived more than 20 years of riding along, carrying top oil for me.

Oh- and yep, I have air forks...

I used to use chainsaw oils until the synthetic 2-stroke oils came out in about 2005 or so. They don't smoke.

[HondaMan]

Darn it.  As I suspected clogged jets. 

Did you get Dash awake?
You can also try this: drain the float bowls and [spray in] add some carb cleaner or brake cleaner into the bowls, full, so it reaches up into the pilot jets. They are the highest point in these carbs, above the float bowl level, and the clog usually happens right at the float bowl level. These solvents will dissolve it, usually overnight. Then you can either try to start it after adding fuel to it, or just drain the bowls (messy!) and fill up with gas again to fire it up.

[Mooshie]

I did get him going again.  I had the joy of dropping the bowls (goodness what a contortionist nightmare that is) and put in the old pilot jets (after cleaning thoroughly).  The ones in there were from a kit and I had asked my mechanic to not put in those but he forgot or some such nonsense.  He started up like a top.  I then did the valve clearance and just yesterday set the point gap and dynamic timing (he was retarded so that accounted for the sluggish throttle response I was getting- or so I am thinking).  I will run him next weekend and if all is well complete a carb sync.
that is all to say after I replaced the spark caps and plugs.  Dash is feeling very pampered right about now! 

[Gurp]

Following*  to read on this one. It's pretty interesting

[scottly]

I did get him going again.  I had the joy of dropping the bowls (goodness what a contortionist nightmare that is) and put in the old pilot jets (after cleaning thoroughly).  The ones in there were from a kit and I had asked my mechanic to not put in those but he forgot or some such nonsense.  He started up like a top.  I then did the valve clearance and just yesterday set the point gap and dynamic timing (he was retarded so that accounted for the sluggish throttle response I was getting- or so I am thinking).  I will run him next weekend and if all is well complete a carb sync.
that is all to say after I replaced the spark caps and plugs.  Dash is feeling very pampered right about now! 

Lisa, while you had bowls off did you happen to note the jet sizes, both mains and pilots, you are using with K&N pods??

[Mooshie]

Pilots were 138 I think. Or was it 135. Which one makes more sense and actually exists?  I didn’t change out anything else. So I didn’t check those. The 138 was plugged on 2 of 4 kickstand side
Bike purrs. Starts right up and only wants choke for a moment. Holds idle at 1000 easily but I set it to 1200


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[bryanj]

Maybe 38 or 40 not 138