Hi im having trouble with my yammaha r1 engine.I blew the last one up.I sourced a new one with uprated carbs and an uprated clutch.It took a while but i eventually got it in and more or less set up how it should be.I just had a couple of small bits to do.so we decided to start it up and see how it run before sliding the engine back.New oil filter and coolant went in.After a couple of attempts we got it started.It ideld fine so we rolled it out of the garage let it warm up and give it a few beans.But it wouldn't rev over 6k so we presumed there was a problem with the carbs so we took the new carbs of and refited the carbs from my old engine and had the same problem. Any ideas.

I am not sure how the carbs fit on the 4xv but on my 5PW I had a similar issue

it turned out that the one of the screws holding the throttle bodies in place was stopping the throttle spindle on the engine from turning its full cycle. Once I adjusted this TB screw to a different angle everything was fine

thanks for the suggestion i just had a look but theres plenty of clearance.

problem now fixed thanks

What was the fix? one thing that annoys me is when I find a forum post with the same problem I have weather it is engine or PC related or whatever, and it just ends with "nevermind fixed it" not directed at you, just would be helpful for someone if they have the same problem.

Dave

i swapped the loom and ht leads