my first post having problems with my 28mm flat slide mikuni carb it idles fine but when I give it any kind of throttle it stalls the stock jets in the carb main jet #180 pilot jet #15 needle jet #175p-8 throttle valve #25 jet needle #5dp39 right now I put a #300 main in it with a #25 pilot my setup stock bore motor with FMF SST full exhaust cfm airbox boysen rad valve with power reeds +4 advanced timeing mix 32/1. not sure what's going on with carb can't get it to move so I can't plug chop it I put the stock 26mm carb on it and runs fine any help with this carb it would be great
vm28-418 flat slide carb help
- Thread starter eric84
- Start date
My thoughts on the VM 28 -418,
Were they not designed for use on 4 stroke engines?
All research I have done leads me to that conclusion XL 185s run good with them.
TW 200s seem to use them widely.
Were they not designed for use on 4 stroke engines?
All research I have done leads me to that conclusion XL 185s run good with them.
TW 200s seem to use them widely.
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it appears all VM's 20mm thru 44mm feature an airscrew, part # 29
http://www.carbparts.com/mikuni/vm20_44.gif
the TM's are listed as "flatsides, which do you have, a VM or Flatside ?
I don't believe a 28mm requires much differing jetting than the stock 26mm.
-check/adjust float height: http://www.blasterforum.com/threads/float-heights-and-how-to-adjust-them.50565/
-try a 35 pilot
-adjust airscrew for highest idle: http://www.blasterforum.com/threads/adjusting-your-airscrew-pilot-jet.51060/
-replace pilot if that procedure says it needs it by # of turns out.
-adjust clip down till it rich bogs, then set clip 1 position higher, plug chop at 1/2 - 3/4 throttle to confirm
-and plug chop the 300 main
http://www.carbparts.com/mikuni/vm20_44.gif
the TM's are listed as "flatsides, which do you have, a VM or Flatside ?
I don't believe a 28mm requires much differing jetting than the stock 26mm.
-check/adjust float height: http://www.blasterforum.com/threads/float-heights-and-how-to-adjust-them.50565/
-try a 35 pilot
-adjust airscrew for highest idle: http://www.blasterforum.com/threads/adjusting-your-airscrew-pilot-jet.51060/
-replace pilot if that procedure says it needs it by # of turns out.
-adjust clip down till it rich bogs, then set clip 1 position higher, plug chop at 1/2 - 3/4 throttle to confirm
-and plug chop the 300 main
I don't no why but its not allowing me to put up a picture of carb.this is info on carb vm28-418 mikuni 28mm flat slide smoothbore carb. main jet #180 pilot jet #15 needle jet #175p-8 throttle valve 2.5 jet needle #5dp39 I put a #280 jet in it with #25 pilot got it to move Now but bogs 1/2 to full throttle not sure on needle jet and needle I'm not sure if the needle jet in this carb is for a 4 stroke or 2 stroke because they sell other series needle jets for this carb. hopeing someone will no.
I'd just give the guy at carb parts warehouse a call and explain what carb and engine you want to use it on, he's the one who helped us figure out what slide and needle was required for the 34mm PJ carb.
really helpful dude, but be prepared to buy the parts he suggest when you call.
http://www.carbparts.com/
really helpful dude, but be prepared to buy the parts he suggest when you call.
http://www.carbparts.com/
