New Carb in the Game

[sldhd700]

I m going to throw a curve at the 90cc group, everyone has been running the 24 mm carb. Have any of you thoughtof going smaller.

We did with a 21mm at first and the results were unbelieveabel. Next we put a power jet in this same carb once again an improvement!

I have seen the rage switch from OKO to Kehien on this message board. These two carbs are so close that with a little tuning they both can perform.

The truth is the 90 is way over caburated.

We ran WORCS two weeks ago and Shaydens bike with this carb and pipe with clutching included, carried the wheels off the line for twenty to thirty feet( we have done nothing inside the motor) with him leading going into the first turn. Raced last weekend with a drop gate the bike would pull the front wheels eight inches off the ground at the start of four motos. It was way cool to see. These bikes with the pipe and carb, stock gearing will run at 51 mph on the asphalt.

You tuners out there may want to think this one through it works.

A few of you probably saw my reply to QJ about letting the cat out of the bag and just letting its head out, well now you know a little.

Shayden Housley #39

[forgiven]

That may help on the low end but I am assuming your top end suffers a little bit doesn't it? I noticed the Pred 90 does pretty well off the start with the 16 and wondered the same thing. It would be nice to hear others with similar experiences.

[bulldogfallon]

21mm for a stock 90 is the word on the street...

I have heard this too...from very reliable sources....

No first hand experience with it, but it seems to be a popular idea.

Time will tell...


How about the 16mm 50 carb on a 70 with a bigger main jet?

That is the one I have been thinking about lately.....


Bigger is not always better

[Logan #34's Dad]

Well boys, I'll be trying all the different carbs on Logan's 70 Metrakit very soon. I do not have a Dyno to make it official but I have a long back yard so I'll use a stop watch and Logan getting sick of being interupted after each change. I also can use a radar gun for top speed runs too. I'll let ya know.

[kenjolly]

I know Gary will be doing some changes today, because he just cant stand not to. I dont have a 90 just some 70's and a 50 anyone tried anything on those two.

Hey Dusty you can use my 21mm off Hayden's 70 on Micheal's 90 if you would like to.

[ecmini1]

This is the same reason we use intake stuffers to create pressure in the cyl. .A smaller carb will increase cyl. pressure. But remember its fuel mixed with air that we need to create a proper burn and a smaller carb can only carry so much air it turn limits the amount of fuel that can be carried this will limit the top end power of the engine. This combo works well on a stock to mild eng. that turns low rpms but when a motor turns more than 10, 000 rpms it needs more fuel. The more rpms a 2 stroke can produce is more top end speed.

Yes, bigger is not allways better.

Hope this make some sence. This is hard to put in text.