Hello this is my first post but love the info I get on here this forum is a valuable tool for me. I have a 1990 Kaw 750 I just bought it has 29000 miles on it but is in great shape. It has not been ridden much and I am having problems cruising at low speed/rpm. it seems to miss just a little. it idles pretty smooth exspecially when warm and has lots of power all the way to redline. It does have an aftermarket slip and a stock air filter(just replaced) also replaced plugs don't know much more about bike. I do know the fuel put in it to get it to me was regular unleaded with octane boost and a bottle of carb cleaner. I have not ran the tank out yet. Is it possible the chemicals put in the fuel could cause this problem or do you all suggest something else? any help would really be appreciated Thanks

 

Welcome, it’s worth a try to drain the tank and fill it with premium fuel. If the carburetor has never been cleaned, it should be removed, disassembled and cleaned. I use spray cleaner and hit every little hole and corner, takes about 5 -7 cans of cleaner. It can also be taken to certain auto parts stores and be boiled in a cleaning solution, this is the best but I find it hard to find the stores that do it.

Low rpms are controlled but the pilot jets so make sure they are clean and you can see down them, same goes for the main jets but they control higher rpms.

Good luck and let us know how it goes.

 

Thanks I will try cleaning the carbs. I am an auto mechanic and don't know much about bikes but I am learning. hope the motor is fine it does have a bunch of miles seems to be just a little noisy would love to get 40000 out of it

 

Get the maintenance manual there a lot of help; probably find it on ebay for about 25 bucks. Shoot, if you’re a mechanic it will be a breeze.

 

yeh, I would pull the carbs and do the cleaning. I use diesel for my parts washer. But just make sure your carbs are clean. Have fun.

Have you checked the valve train yet? All motorcycles seem to be noisey.