Carby Mikuni VM 18mm

[Tyler6357]

The carb is leaning out at idle mostly due to it's size.When you can put some throttle input and let it snap back to idle then it climbs is lean.As is a 70 jet for that setup you have this with an MZ pipe no?

Yes, MZ pipe, 70 stock jet, should I try to jet up or maybe down? The RT carb is 15mm, would the Mikuni VM solve it?

 

[Street Ryderz]

Yes, MZ pipe, 70 stock jet, should I try to jet up or maybe down? The RT carb is 15mm, would the Mikuni VM solve it?

It will help for sure. you will still have to put bigger jets.

 

[Jrok]

i had similar issue with that setup /carb. its hard to get that read block to seal up at the intake. (especially if you opened up the intake port) . try spraying some brake clean/carb cleaner around the reed valve while running to check for leaks. The brake clean shouldn't affect the way its running if its sealed.

 

[Will'smotobikes19]

I tried the #90 and it was way too rich, no power only went like 15mph. Oily plug and was also 4 stroking and I’m really scratching my head because someone said use a 90 and they said it was running rich maybe they meant gas to oil ratio don’t remember and I think its the opposite problem than before. I think maybe a 75 or an 80 is what it needs. Still unsure how to tune one of these. 1,000 ft above sea level.

 

[Tyler6357]

I got the carb but I haven't tried it yet. I had to order an air filter separately because it didn't come with one. I don't have any other jets than the stock ones yet. but I will try it and report back..

 

[Will'smotobikes19]

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.

 

[Frogslayer]

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

 

[Frogslayer]

A walbro twin needle carb would be so nice for changing things a lot or traveling or even changing seasons. Just twisting needle for hi and a needle for low.

 

[Will'smotobikes19]

I don't think I would go under the stock 70 because of how it was running before. It wouldn't have any climbing power and would just coast to a stop. Think it was lean since riders say it needs bigger from factory.

 

[Tyler6357]

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

I was thinking that too. I friend told me to use a 67 main jet, but he didn't have a reed valve.