Lazy cylinder...

[terry davies]

Right hand rear cylinder appears to be lazy. I have good compression on all cylinders, between 165 and 175 psi. New plugs and good spark at all cylinders. With air box removed the slide in lazy cylinder seems to react slower than other 3 cylinders and vacuum seems weaker also. Have checked diaphragm and that is fine. Have checked valve clearances and they are correct. Have checked for air leaks around base of carby, nothing detected. Any suggestions please?

 

[KJShover]

Re: terry davies

Welcome to the forum Terry.

Have you synced the carbs? maybe that carb is a little behind the others.
Has anyone ever played with the Air/Fuel mixture screws?

Also there might be a little bit of crud slowing up the slide.

 

[timax]

I have the same issue, its not the sync or the mixture screws:ummm: or the cylinder,valves ect ect

Without the bike running pushing the slide in by hand and then releasing you can notice a big difference in the right rear carb..from the other 3.. Lazy about sums it up..

Now what the hell is causing it:ummm: What would slow it down,what controls it besides the springs and diaphrams???:confused2:

 

[Rhoy Carter]

The needle could be dragging on that one carb, if you have shimmed the needles that one could be in a bind

 

[Nicki66]

I am by no means a carb expert, but maybe you have a pin hole in one of your carb diaphragms.

 

[naughtyG]

It could also be that you just need to take that slide out, give it a good clean, then refit it with a little WD40 and see how it feels.
If it's still binding try removing the needle - you can then find out if it's the slide itself or the needle that's doing it.
Take a good look in the bore the slide sits in - it could be gummed up. Carb cleaner should take care of that.

 

[timax]

Thanks for the info and suggestions guys.. To be honest i have not looked at it real close yet, getting tired of working on this bike.. Anyways the carbs have been completely rebuilt, new fuel tank,filter and lines all new boots both carb and vboost... I did have the carbs shimmed to a 3/4 clip position,, right now im not using any shims as i had a lean condition, raising the needle 1/4 clip took care of that...... I dont think the needle is the problem, like everything else they are brand new stg 7 units.

I thought maybe a weak spring, but why only one and the others are all fine.. could be a pin hole in the rubber:ummm:.. just strange its the same carb as terrys bike.. slides are clean as a whistle as are the bores, i think my friend Mark can attest to that...

If and when i find the problem i will post it here,

Thank You