Hi Guys sorry this post is a cry for help i bought a 96 about 3 months ago that in the last 18 years only covered 800 miles so i began to refresh the bike. new radiator, hoses, coolant housing, water pump seals and gaskets, sump gaskets, exhaust gaskets, Carb overhaul kit, fuel petcock also flushed and cleaned the tank due to dirty fuel.

during this i damaged no2 carb body as the pilot jet was welded in situ as most of the others where but i got those out ok. so i bought another bank of carbs split them down and cleaned overhauled it and rebuilt my bank (all new jets ,seals, o rings etc). refitted the carbs fired her up and revs stuck at 3000 still no3 not firing - more tweaking and now idles ok but no joy with no3 still. so done so far

Checked spark on all 4 cylinders - OK good spark

Checked compression on all 4 - OK (165-170psi)

checked fuel bowls - all have fuel in them

squirted easy start in all 4 - only no3 dosn't respond to it

carefully covered all inlet trumpets and the sliders respond apart from no 3.



Split no3 carb used carb cleaner again on all holes, blown through with compressed air, checked diaphragm no splits rebuilt and re installed - same issue.



Vac tube on no 3 checked and is ok - no splits



so im at a loss, my next check is to see if the exhaust manifold is leaking massively on that cylinder, visually looks ok.

I have a parts bank of carbs that need a bloody good clean lots of varnishing and a fine sand substance lurking about, my carbs wen split looked brand new so i was gutted when i broke one of mine.



any help appreciated



regards Ian

 

Hi and welcome to the forum. Something doesn't add up. You have spark on all 4 cylinders. You have good compression on all 4 as well. You spray starting fluid into the throat of cylinder 3 and it doesn't respond to it. This doesn't make sense. So you can get it to run on 3 cylinders (roughly I'm sure) and spray starting fluid into carb #3 and it doesn't respond to it? Plugs are all in good shape? An exhaust leak is not going to prevent the engine from running. I would not waste my time on that.

 

Thanks for the response. idodirt
im at a complete loss ive also swapped out the plugs with 2 and 3 to see if the issue moved it didnt! not sure where my next step is other than to clean and overhaul my spare bank. ill see if i can get a video up on you tube.


cheers ian

 

So the exhaust pipe on #3 is essentially cold?

 

If you pull the plug lead on #3 the engine runs the same?

 

Yes cold header and exactly the same plug lead off

Thanks again for trying to help me out


Plug condition after pulling it

 

What does plug #3 look like when you pull it? Is it just dripping wet? Have you swapped the ignition coils from one to the other? If you pull any of the other plug wires, the engine dies?

 

That plug looks dry, not wet with fuel? If it is not firing, it should be wet.

 

You're plug wires are routed like this?

 

Apologies the plug was slightly wet when removed not soaking, im in the process of changing the coils over.