Holy horsepower!

[yamaha225dr]

That was a second gear launch also!

[yamaha225dr]

Nice thread on fine tuning a carb so many times you get people too afraid to talk jetting cause of melt-down ! I run a 39 PWK on a 250 port-polish (little big) V-force3 esr pipe no box and i like to pay attention air temp. and elevation ! I think i got a 160 main in now......careful those jetts snap easy !

What is the elevation where you ride? I wish there was a decently priced fuel injection kid you could buy to ditch these carburetors! It would sure make jetting a lot easier, if you knew how to adjust the fuel trims.

[barnett468]

Hello


There is a company that makes an altitude compensating kit that easily adapts to a carb. They are often available on Ebay for around $100.00. Many of the Pikes Peak racers use them. They are sometimes called Vari jet.

[yamaha225dr]

Hello


There is a company that makes an altitude compensating kit that easily adapts to a carb. They are often available on Ebay for around $100.00. Many of the Pikes Peak racers use them. They are sometimes called Vari jet.

Yea, I know it by "Dia-A-Jet" unless the company has changed names or its a different one.

[barnett468]

Hello

Yea, I know it by "Dia-A-Jet" unless the company has changed names or its a different one.

That's it, couldn't remember, thanks.

COMPRESSION RATIO - There is a loss of 5 psi cylinder cranking pressure for every 1000 foot increase in elevation so if one goes from 160 psi cylinder cranking compression at sea level it will be 135 at 5000 feet in which case it could be compensated for with a higher compression head or thinner head gasket etc.

[keister]

Thanks to this thread, I was inspired to make the jump. ATCtim and I installed V Force 3 reeds, PWK 36 mm, and ESR5 pipe today. Hardest part was streching that big stupid intake boot. Now I have big power all over the rev range- especially the midrange. Great call. Lovin it. A few quick bolt ons made all the difference in the world!!

[yamaha225dr]

I bet with those mods all done together you really had a nice boost in power! The initial installation is the hardest but the rubber boot will stretch and make fitment a breeze.

[keister]

It worked!! I finally got a nice test ride on it at Ashtabula Pine Lake Nationals over the weekend. The R just screamed down the straightaways and almost pulled me a holeshot in my B-class heat race. Once again, thanks for the inspiration in this thread. Now, if I can just find a way to catch that pesky Yamaha.

[yamaha225dr]

Good deal! I haven't gotten to ride mine in a couple weeks, I have been busy getting ready to move.

[roonie]

could i do this mod to my Big Red 250es or are they different. thanks

[RIDE-RED 250r]

could i do this mod to my Big Red 250es or are they different. thanks

No, that carb is way too big for a Big Red.