Carb rejetting

[bazit]

OK guys
Any advice on up jetting a 380 which has now been over bored by 1.5 mm has had head skim 20 thou ,its now got 9 bar and Pods
The reason for the question is simple the bike starts fine on choke but will not run without keeping the choke half way on ,What would be the answer bigger jets ? The exhaust is standard. What about needle position should that be changed .
All advice welcome
Barry

[Barry S.]

Sounds like carbs stopped up somewhere not getting fuel, overbore and higher compression shouldn't do that.

[bazit]

Ok
All carbs have been stripped and sonic cleaned.
Barry

[Vintageman]

As Barry S said those little changes you did should not affect jetting to a point you need to run on choke.

What do you mean it won't keep running. It won't idle or it wont go down the road mid throttle etc.

Was it running fine before you cleaned carbs and/or modded engine.

[jabcb]

Some time ago I did have a problem that sounds somewhat like this on an early triple that had the choke operated by a lever on the handlebar.

It was necessary to leave the choke partially on all of the time.
In my case the choke mechanism was all messed up.
The problem was solved by (1) making sure the choke parts were good & were properly adjusted, and then (2) adjusting the carbs (air screw & idle).

A shop did the repair work, so I'm not sure exactly what the issue was.

[JFISHSOLEVIBE]

It could be pilot jet I'm accordance with the pod filters. I went up a jet size when I installed them for safer mixture condition however I never had a problem with idle to the point where it needed choke. Have you wound out the air screw to see if that improves it?

[bazit]

Hi all
I will start by saying that the engine before all the work was done was really a non runner with poor compression(although it did start and run sort of ) after the work was done the first kick it started .I have put the air screw @recommended 1,125 turns out ,I will be adjusting this today to see if I can achieve the desired tick over .The driving down the road cannot be achieved a the bike has no wheels as these are away being re chromed .
Thanks for all the advise I will keep you posted

[Coyote]

1,125 turns out the screw would be at my house I believe you meant 1.125 or 1 1/8. On the serious side, up one size on your pilot jets should cure your problem. Leaving the choke partially on richens the mixture. + one size on the pilot jets will compensate for the needed tad of extra fuel it wants.

[ConnerVT]

Those folks from the UK use the comma for a decimal point. (This is a site that could definitely use an English to English translator. )

With the bike not yet in a rideable condition, my best guess is that it either isn't idling as it should, or it is trying to stall as soon as you blip the throttle. If this is the case, I don't think changing the pilot jet up/down a step will make much of a difference, even with a motor that's been bore/skimmed/podded/etc. Sounds more like some passage/jet ain't fully clear, or possibly an air leak making things lean.

[Coyote]

Those folks from the UK use the comma for a decimal point. (This is a site that could definitely use an English to English translator. )

I didn't know that. I stand corrected. I was just funnin anyway. If the bike wont idle or keeps wanting to stall at idle, I still contend it's the pilot jet. However I agree that switching to pods shouldn't require any carb modifications at all. We still need to determine how it responds and how it runs up in the R's a little. Running with the choke half on is not an option.

[bazit]

Dont worry about the funning I would not be offended ,as skin is as thick as elephant hide .
Regards
Barry