Proper Jetting in 250R engine

[BNRturbos.com]

Hello all.

I am a newbie. I just bought an 86 ATC 250R and I am doing some tuning. It has the wisco hot rod/piston combo with a standard bore block. There is a little porting done but I don't know how extensive it is. It is a fresh built engine and I bought a 38mm Keihen carb fitted it to the trike with a bit of fabrication. Anyway, I put an EGT gauge on the bike to monitor temps to help with tuning.

I have a full exhaust system and reed upgrades on the bike and it ran pretty good with the 32 pilot jet and the 162 main jet. The egt's were getting too hot for my taste and there was a little knocking above idle so I bought some new jets. 52 pilot and 175 main. Now the bike runs totally awesome and there is no knocking but as soon as the clutch hooks up in 4th/5th 6th gears the EGT spikes past 1300F. I lift when it spikes so it doesn't lock up. Now I have to buy bigger main jets and get that EGT down.

The bike is incredable to ride even with a slipping clutch. 1/2/3/and part of 4th the front wheel stays up:D. BTW I have another clutch to put in just havn't done it yet.

Does anyone here have any reccomendations for jet sizing for my trike? I know I have it somewhat close but I don't want it on the edge when I get up into the gears..:TrikesOwn .

Bryan

[PowerTech]

i never mess with the pilot jet.

they allways seem to take off just fine and there is a idle adjustment screw and that seems to be enough for me.

run with the needle as high up as you can with out it being a dog acelerating.

and i think the EGT gauge can drive you nuts . just taking a look at the plug and how it runs is good enough for me. and my top ends last forever.

my engine setup is close to yours and i am running a 180 something i forget exactly.

[BNRturbos.com]

Hey Thanks for your input.

I will order more jets Monday. 180's main jet should do it. This 3 wheeler is an animal! I weighed it on corner scales and it weighed in at 270 lbs. Put about 45-50 hp in this thing and it can handle most anything!!!

I have 2 other 3 wheelers but they are the old 200m and 200es. I bought this 3 wheeler b/c I always wanted one, but another reason is b/c of a grudge match with my family members which have the new brute force 650's. I told them I would beat em in a 80's 3 wheeler!!! So I am deep into this thing trying to get it reliable and in good physical condition. It's an aggressive/ good looking 3 wheeler and I dont regret buying it on ebay sight unseen...

Bryan

[PowerTech]

that thing will piss all over a brute force.

dont regret buying it ,are you kiding me. you just made one of the best decisions of your life. you now own the best bike that there is.

[BNRturbos.com]

Yeah I am in love with it! Cant keep my eyes off of it when I work. I was supposed to finish 3 rx7 turbo upgrades today, but then got to tinkering on the R. The jump from the 162 to the 175 is a night and day power improvement. I had a smile on my face after I rode it a few minutes. This thing is making more and more power the more I mess with it.

It is my first 2 stroke and I don't want to kill it by being lean. Very similar to a rotary when tuning! Rich Rich Rich!

The Brutes are quick, but they fall on their face at 30MPH. lol. Not to mention they are heavy turds.

Bryan