Jump to content

Major fuel issue in 83 Maxim 750


murben
This post is 4333 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

So, i have a 1985 maxim 750 that has been running great up until now. All of a sudden, when i start the bike, fuel starts pouring out from under it. At first, i assumed a fuel line had come loose or broke, but after tracing it out, it looked like it was coming out of the rubber boot that covers where the drive shaft mates to the engine. After pulling back the boot, sure enough, it was a mix of gas and oil (mostly gas now) just pouring out from the spot where the shaft leaves the engine case. Any idea what exactly would cause this to happen, and happen this bad? I'm assuming piston rings or something, but what could cause it to be this bad all of a sudden? The gas just pours out of there in a steady stream.

thanks for any help!!

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.

Hi Murben, It might not be as bad as you are thinking, it's possible that one of the 4 floats has got stuck down and is pouring fuel into the engine via the carb inlet, sounds horrible what your describing but I think that it might not be so bad, You will have to replace the oil in the engine (contamination) before you can use it again but that is just like any other service plus you will need to replace the oil filter. What I don't understand is why the carb overflow is not working ie if your float gets stuck it should come out of the top/side of the carb and not fill the engine so check to see if one of the overflows is bunged up with crud, other than that it should be a straight forward fix to remove the carbs ( horrible job) and check that the floats are ok and the valves are working ok, don't forget to check the valve seating up inside the carb as sometimes they wear out and you will have to replace the whole thing (small pointy plastic bit with metal end and seating) that should see you up and running again, hope some of this is going to help. :jossun:

P.S see this is your first post on this site, we like to have an intro from new members (New members INTRO SECTION) so perhaps you would be kind enough to do that next? just say who you are where your from and what bike you got. Always nice to intro your self before asking strangers for advice don't you think? :eusa_whistle:

Link to comment
Share on other sites

  • 3 weeks later...

It is most likely the diaphragm in your petcock. It is leaking gas through your vacuum line into the crankcase then out the air box. Your engine is flooded with gas and oil you need to change the oil. I have an 82 maxim 750 and that worked for me. My bike had the same symptoms. I used I diaphragm from a suzuki model that was compatible. Good luck

Link to comment
Share on other sites

  • Who's Online (See full list)

    • There are no registered users currently online
  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...