87 se50 speedo question

[CG Elite]

New to the site and just bought my first scooter in about 25 years. I have a question.

I am in the process of finishing a metro rim conversion on a 87 se50p iowa (i know). Will the new 90/90-10 front affect my speedo much? If it helps any, it has been nearly fully derestricted and runs 43mph on the flat.


Thanks for any help. Great info on this site.

[swimmingfree]

all moped speedo are off my 10% the taller tire well make your speedo closer to the real speedo you are doing so dont freek out when it says your now doing 40 instead of 43 ...
swimmingfree

[Wheelman-111]

Greetings:

If your SE came with a 2.75, a 90/90 will read very close to true groundspeed, maybe a hair optimistic. I tested this with a mounted Garmin several years ago and got 3% Pessimistic going from 3.00 to a 3.50 on my Elite.

[CG Elite]

Thanks for the help. The elite pulls alot harder than my old spree did.

I have a 63cc overbore jug for this, can I run the stock carb and exhaust?

[Wheelman-111]

Greetings:

Lots of smaller-diplacement kit riders use stock carb and pipe. It's important to keep the stock airbox to minimize issues with the hard-to-modify pilot circuit. It's too small, and long coast-downs can cause heat spikes otherwise. Jet the Main to 90-ish and it should be good.