Hey guys,

I'm not all too sure how the Yamaha Dual Intake System works, when my bike is under heavy throttle it seems like it's being restricted in the top end of the revs, only a new problem was, going mint a couple of weeks back.

Is it something a home mech can look at or do I need to take the carb set up into a shop.

Cheers

Its two carbs in one from what i understand of them, a conventional cable/slide carb side by side onto a CV carb.

On the smallest throttle openings the cable/slide (carb 1) will do the work and as carb1 slide is opened further then the CV carb (carb 2) will chime in. At full throttle both carbs would be full open if they are set right.

If it was running OK a short while ago and then suddenly a big difference then rather than something out of adjusment I would think something has failed...perhaps the carb 2 diaphragm ?...i dunno I'm no expert but thats where I would be looking at carb 2....the CV carb

diaphragm?

jet?

intake rubber?

Dont go messing with the adjustment screws unless you know what they do! For example on my TTR600 YDIS carb, I have to open carb 1 by 7mm and then adjust the sych screw so that carb 2 is just beginning to open at this point.

It would benefit you to get a manual if you really want to learn about yours

Oh yeah cheers mate, might just clean it out and see what happens. hopefully not more $$$.

Oh yeah cheers mate, might just clean it out and see what happens. hopefully not more $$$.

Had this problem on my XT550.

Firstly check the pipe between the cards is ok and not split, this is a balance pipe from memory and mine was perished.

I would then check for dirt etc in carb, as an easy fix. (apart from getting them of the rubbers!)

Worst case - which mine was the CDI unit was failing. (Was ok on part throttle but major misfire from around 3500 rpm on. Replaced it and fixed completely.

Hope its just dirt!

Nick