4 replies to this topic

[johnv]

1968 998 cooper twin 1 1/4 sus, evo 001 , lightly ported head etc

I can set the carbs to balance and tick over at 1100 rpm, which seems to be about what it likes without things getting too rattly .. BUT .. the revs will gradually drop until it stops. I would have to set it to idle much too high for this not to happen.

On 2nd set of rebuilt carbs .. these ones have professionally fitted new spindles and butterflies, new jets etc .. GY needles if it makes a difference.

Nothing appears to be leaking anywhere .. any suggestions as to what to try next? thanks

 

Otherwise the car performs really well, engine is strong and pulls well, if fact it goes like stink for a 998!

Edited by johnv, 23 April 2019 - 03:51 PM.

[Twincam]

Were the bushes replaced when the carbs were rebuilt?

[johnv]

Were the bushes replaced when the carbs were rebuilt?

 

yes they were

[ACDodd]

Have you centred the jets properly and the pistons seat fully down with no restrictions?
Have you checked the manifold seal and all the gaskets with wd-40 for possible air leaks? Are both jets the same distance down from the bridge?

Was this problem present with the previous carbs fitted?

Ac

Edited by ACDodd, 23 April 2019 - 05:49 PM.

[johnv]

I think the answer to all (well, most) of these is yes .. the problem was there previously, the pistons clonk down nicely (spent hours!) 

I'll need to check the jets distance, that could possibly be a bit out

I have some leak spray stuff, I did try it a while ago, but I'll give it another go