Carby Mikuni VM 18mm

[Will'smotobikes19]

2 stroke tuner just made a video about a pumper carb saw it in suggestions. Well not much of a video.

 

[Will'smotobikes19]

The VM18 should be able to work though. I actually took roberts advice and that's why I got it to begin with yes its the zeda robert as well lol. I've heard alot of bad about that guy. I was wondering if I could use the VM18 on a 79cc predator but don't know what jets it would need then either. Just removed gov but now I need feeler gauges.

 

[Tyler6357]

The VM18 should be able to work though. I actually took roberts advice and that's why I got it to begin with yes its the zeda robert as well lol. I've heard alot of bad about that guy. I was wondering if I could use the VM18 on a 79cc predator but don't know what jets it would need then either. Just removed gov but now I need feeler gauges.

Yeah, I have heard alot of bad stuff about him too, but I have never done business with him and can't really say anything bad. He posted a video using a Mikini VM18 on a 66cc china girl but no reed valve, he neglects to say what jet size he is using. He is clearly trying to sell his stuff and I'm not posting his as any kind of endorsement of his business.


Also, I found this video on how Mikini carbs work, he is using a slightly larger carb than the VM18 but it's still useful info.

 

[Street Ryderz]

For me the 90 just didn't work right I put ina 22.5 pilot jet. Really annoying that Its running like crap and blowing tons of smoke out the exhaust. The reed valves are supposed to help but I think they require a bigger jet since they kinda block the flow in a way or limit it. The carb was $65 so I really want it to work. I'm thinking 75 or 80 jet would be right. It actually picked up more speed with the 70 jet. So I went from lean to rich because I took someone's advice to use a 90. They probably live AT sea level in florida or something lol. Don't understand tuning and elevations yet.

lean out the bottom end/idle first so that throttle input isn't just dumping in more fuel ontop of to much to begin with then set the needle for throttling up responce and then worry about the main.An 18mm carb with reeds deffinatly needs above an 80 jet for the topend your 22.5 should be good maybe even lean tbh but a video of it running would help to see what's going on.

 

[Street Ryderz]

If the reeds really do obstruct some flow, which they do, you would need a smaller jet to let less fuel into your less air situation

Because the reeds slightly restrict the flows velocity a larger jet is used to get more volume at the lower rate.

 

[Street Ryderz]

Any type 18mm carb even on stock engines takes an 80-82 main jet,jumping from 14mm to 18mm but still the same size jet should tell you right there something not right.

 

[Sumsloppymeet]

i stuck with a 65 main with that setup but my altitude/sea level is only 17ft lol

 

[Will'smotobikes19]

I’ll probably order a 75 and an 80. Was blowing smoke out the exhaust and skipping when I was giving throttle and when I tried to accelerate I could feel it slow itself down. Might even get a jet kit I heard about the 22.5 pilot from Amos. It’s 48mm bore ported with OZ reed. It’s not much higher than the stock because it’s still 38mm stroke.

 

[Sumsloppymeet]

i swear by the 22.5 pilot jet on the vm18 worked great on all 3 setups ive tried so far i stay with the 22.5 pilot and depending the weather 65-70 main for me

 

[JerboaJohn]

how close would those jets ^ be to a ballpark tune on VM 16? Im already running richer with #72 on the SHA, it won't take anything leaner without backfire at half throttle n no load
or is it a totally diff ballgame then VM 18