MRC Forum- brought to you by www.morini-riders-club.com

I'm finding the 350 X1 has a high idle which is either float height or some other issue that is fuel related. I see in other carb posts mention of a carb balance tube - is the largest of the 3 brass tubes present in the carb bodies for interconnection and not just breathers?. The carbs are original square slides...
thanks
Phil

If you have a high idle which can’t be got rid of by sensible adjustment of the idle speed and mixture screws, and that you have checked you have sufficient free play on the throttle cables such that the slides aren’t ‘hanging’ then you need to rule out an airleak downstream of the carb or at the carb body itself.

The balance pipe is normally on the bigger stub tube on the engine side of both carb bodies. This either links both carbs directly or might have an extra connection to a vacuum fuel tap if you have one. Rule out leaks there by blanking those stub tubes off with a short piece of rubber tube with a tight fitting plug or bolt in the end or similar. You’ll need to use the manual reserve fuel tap of course if you have one, as the vacuum tap won’t open if you have one.

Next rule out air leaks in the inlet rubbers between the carbs and heads by spraying the area with some easy start or other hydrocarbon spray- any change in engine running will signify the spray is being drawn in via the leak area.

OK, so that is my problem - I have those larger diameter brass tubes on the carb venting to atmosphere! - the perils of putting a bike together without a manual. Surprisingly, it starts and runs very well with all that extra air being sucked in and doesn't run when I block them off. Back to the mixture drawing-board so to speak.