Mikuni Carburetor Rebuild Kits

[TEWKS]

If you have an aging dirt bike or ATV with a Mikuni carb it’s pretty tough to find a quality rebuild kit for them. Most kits are junk and cost one local mechanic a motor. Anyway, this company has kits directly from Mikuni which I believe had never offered their own rebuild kits before.

 

[TEWKS]

Can anybody spare a little of this before I start that project?  It’s about two hours just to dig them carbs out of the machine and then the thinking work begins. 

[TEWKS]

Was gonna start digging them out this morning but, I’ve got an eleven o’clock poke in the arm I’ve got to take care of first. 

 

[RightSpin]

My two cents Pat.  I've rebuilt the Mikuni on my KTM three times now and the float valve still leaks.  Spent more than a new carb trying to save some scratch.  Might consider simply replacing with new instead of rebuilding.  Especially if Ethanol has been in the tank most of its life.

[TEWKS]

Thanks Steve, I put out the 93 bucks for the kit so I'll give it a go. But yeah agree, sometimes you just have to know when to call it a loss. I'll see if I can motivate myself enough tomorrow to get them out of the machine.

[RightSpin]

Good luck!  👍

[TEWKS]

Choices...sit on the couch or take out carburetors?  I took them out. It actually took me a lot less time than I remember. Maybe I was being a little more cautious the first and second time or maybe, it was because there was a first and second time.  

 

 

 

I’ll get back to it on Tuesday I think.

[TEWKS]

The point of no return. 

 

[TEWKS]

Fail # 1  
They went back in, hit the starter and bam it fired right up!  Joy...for thirty seconds and then it crapped out.  Very similar to what it was doing before. I did have a leaking fuel petcock that I took care of last night. My air filter foam seal has disintegrated because of age but that shouldn’t keep it from running.  I took the carbs out and reinspected the jets and all were clean. I was worried that a piece of that foam got sucked in.
 

I changed the choke O ring and that made it very stiff to operate. I switched that back to the original. Also, swapped out two O rings on the main jets that seemed a little sloppy. 
 

Just blabbing here while drinking coffee, I’m gonna give it one more shot today and see what happens. (getting good at taking them out and putting them back in, btw)  If fail # 2 happens I have a local shop that I’ll bring the carbs to and have him go through them.

 

[Rougarou]

At least you have the tertiary back up plan..........must be used to that triage thing

[TEWKS]

Maybe  I should try and replace this 19 year old spark plug (that has no spark) before I go any further. 
 

[wbw6cos]

Ding, ding, ding, ding, ding!!  

[TEWKS]

Yup we do have a winner! 
 

Fired right up with the new plug!  Funny, it didn’t act like a fouled plug when it initially ran after rebuilding the carbs.  I didn’t run it long enough to see if it was going to continue to run because I need a new air filter and filter cage.

But...feeling confident! 

[TEWKS]

The Raptor is alive!  A new plug along with an air filter and of course, the carb rebuild. I just gotta button on the body work and it’s done.