2 STROKE WORLD .net

The 2-Stroke Garage => Turning Wrenches => Topic started by: Greaser Greg on February 28, 2020, 01:05:55 PM

Title: Vm28 pilot jet thread size
Post by: Greaser Greg on February 28, 2020, 01:05:55 PM
Anybody know what size tap fits the pilot jet threads?
It is m5x0.8 for all carbs that use that style jet.
Title: Re: Vm28 pilot jet thread size
Post by: SoCal250 on February 28, 2020, 03:12:16 PM
VM22/210 pilot jet for Mikuni is M4
Title: Re: Vm28 pilot jet thread size
Post by: Greaser Greg on February 28, 2020, 03:35:41 PM
https://www.mikunioz.com/shop/vm22210-pilot-jet/?v=7516fd43adaa
Why are these different?
Looks like one goes by the outer thread diameter vs. other at end of jet. Going to try m5 tap, will update after.
Title: Re: Vm28 pilot jet thread size
Post by: m in sc on February 28, 2020, 04:05:48 PM
If you are retapping the threads, the carb is probably fucked.
Title: Re: Vm28 pilot jet thread size
Post by: Greaser Greg on February 28, 2020, 05:59:16 PM
Takes the jet ok. Threads match. Why no good? To much turbulence above jet?
Title: Re: Vm28 pilot jet thread size
Post by: teazer on February 29, 2020, 11:43:38 AM
Sudco page is simply to identify the jet by its diameter.  It's not a measure of the thread size.  I think that's what someone pointed out already.

So the question is: what is your real issue?  Is the jet not screwing in properly in some way?  Please describe the actual problem and maybe someone will be able to advise what's wrong.

Did you remove a jet and it won't go back in correctly or is the new jet not screwing in or what?  I don't understand what you mean by "turbulence above jet".
Title: Re: Vm28 pilot jet thread size
Post by: Greaser Greg on February 29, 2020, 01:03:16 PM
The slot stripped out so decided to drill it. Used a tap to clean out the brass. Got lucky I guess cuz it worked and the new jet is in at same depth.
Title: Re: Vm28 pilot jet thread size
Post by: SoCal250 on February 29, 2020, 04:27:46 PM
Quote from: Greaser Greg on February 28, 2020, 03:35:41 PM
Looks like one goes by the outer thread diameter vs. other at end of jet. Going to try m5 tap, will update after.

After looking at it again, you're right. I should have just dug one out of my spares and measured. In any case, glad you got it figured out.  :thumbs:
Title: Re: Vm28 pilot jet thread size
Post by: m in sc on February 29, 2020, 07:49:38 PM
gotcha. usually when a tap has to come out for  a jet, there's bigger issues. glad you got it sorted.