[SOLVED] Had a fuel issue crop up today.

So I went out for a nice 150km ride today. Filled up with premium since i hadn't run the good stuff yet this year. Everything was fine till the last 15 or so km.

She started loosing 1 or 2 cylinders, exactly feeling like it would if i was running out of gas before switching to reserve. I've got 1/2 a tank still... switch to reserve, no improvement. UNLESS I crank on the throttle, then she picks up and goes like normal, let her come back down to 80km/h runs like crap, goose it and it clears up.

So I get home and start to think of what could be the issue:

bad gas
TCI connections
plug went bad
etc etc

Figured, might as well start somewhere easy, check the plugs.

All looked fine except for #3, wet gas fouled. OK now we're getting somewhere. First thought is I lost my vacuum valve on the petc0ck and she's sucking gas straight from there (#3 is my vac for petc0ck). Checked both ends of the vac line, dry, doesn't smell of gas, nothing pouring out of the petc0ck when the line was off from vac port.

OK, next, am I getting spark? All 4 have spark when rested against engine block.

Hmm.... i'm running out of quick options now. FLOAT STUCK!

Tap tap tappy on the bowl, didn't hear anything drop, figured if it was stuck it shouldn't be now (I do have clear gas line, and i didn't see it emptying like it was dumping to #3.)

OK before i went on my ride i reset all pilots to 3 turns out to see how she'd run... compared with how i DID have it set.. hmm it WAS 2 turns out. OK maybe it's just slowly fouled itself over my ride today. Reset to 2 turns and go for a short run.

Still the same, *sigh* ok.. I have spark when NOT under compression. If I pull each plug while idling, all 4 DO have an effect on idle. Seems to idle fine at 1k rpm, but as soon as you give it just a little throttle while releasing the clutch, it sounds like it's dropped 2 cylinders. TILL you goose it, then it cleans up immediately and goes like a scared rabbit.

I didn't check the connectors for the coils at all, I should do that later today, but i can't see that being the issue. I CAN see the coil itself being an issue, will check tolerances when I go back out.

I just checked valve clearances last week, #1 exhaust is max clearance, and #3 exhaust is min... hmmmm..... it was right at .152mm hope i didn't burn a valve, no compression tester here I can't see it being that tho, as it idles fine.

You guys got any other ideas that I may not have thought of?

 

Re: Had a fuel issue crop up today.

Howlong has it been since the carbs had a good cleaning?
Might be some dirt plugging up something. The enrichment circuit on #3 may not be closing off.

 

Re: Had a fuel issue crop up today.

I did check to make sure #3 choke was closing all the way. Regardless the carbs come off tomorrow.

I'm betting I dropped a main jet, that's the only way I could get THAT much gas at idle.

Put a new spark plug in #3, idled her for 10 seconds, and it was already almost dark brown, so it's got to be sucking massive amounts of gas from somewhere, it's not the petc0ck. I pulled the pilot screw and it's fine, 1/2 turn out made the plug darker lol so it's gotta be the main jet dropped.

I did notice that I must have missed tightening my carb rack when i put it back on this past winter, bottom rack screws were all loose, one was gone So it very well could be i didn't tighten my jets in the bowl as well.

That or float stuck wide open, either way i'll find it tomorrow.

Good thing it's supposed to rain all day lol.

I'll update when i find anything.

DOH! Don't have my meter here for checking coils

 

Re: Had a fuel issue crop up today.

So I pulled the carbs, took #3 bowl off, and there lays the pilot jet out of it's post Good that's an easy fix (except pulling the carbs lol)

Checked the other 4 just to make sure they were all tight.

Yay! Runs like it should now.