high revving tickover

[philwright]

Hi All, my 88J slingy always starts ok from hot or cold and goes like stink but I've found once its fully warmed the idle is quite high and when revved it doesn't settle into a steady low idle instead it  seems to slowly return to a steady tickover, the throttle response seems to be on a delayed action !..i've checked the throttle free play and made sure its not snagging anywhere, next job is to see if any of the carbs slides are a bit lazy....any pointers please?

Edited May 17, 2018 by philwright
typo

[bigpants]

My first thought would be an air leak somewhere , a crack opening up as something warms. I've heard a simple test is to warm up then spray something non-explosive around the suspected areas. If it gets sucked into the engine you should hear the difference.

[Foz]

Google " factory pro carb tuning guide " the high rpm section. It may be that your pilots need adjusting

[Billythekidd]

On 17/05/2018 at 10:25 PM, Foz said:

Google " factory pro carb tuning guide " the high rpm section. It may be that your pilots need adjusting

The factory pro tuning guide is fecking brilliant, although does sound like an airleak, as said above spray something like wd, over the carbs if there is a leak the revs will pick up

[Adz]

O-rings on the carb rubbers are most likely worn out and not sealing properly anymore, causing air leak when warmed up

 

[philwright]

Thanks for all the replies...

4 hours ago, Adz said:

O-rings on the carb rubbers are most likely worn out and not sealing properly anymore, causing air leak when warmed up

 

Specifically which o rings are we talking about ?...and whereabouts are they, i'm a complete carb novice.

Edited May 20, 2018 by philwright
typo

[CockneyRick]

The ones that sit between the carb rubbers & head  

[philwright]

Ok thanks ...i'll get on it.

[Adz]

And when you change them, swap the pozi head screws out for allen heads and you can torque them all up the same ;-)