I just got everything on my 250R back together. New carb(Keihin 38 mm air stryker), new reed valve(V-Force 3), thumb throttle, cable and new ring and seal for the exhaust pipe.. I was running a Mikuni 40 mm flat slidecarb with twist throttle(Hated it!!!) and broken reed pettles(I was told they were new when I bought it(lieing sack!!!). I adjusted the throttle cable while the carb was out so I could see exactly when the slide moves as the throttle is pushed. I started with a 180 main jet and put in a new plug. I started the bike up and warmed it up and ran it up and down the street a few times. Wow! The response was amazing compared to my old setup and alot more noticable power. Right after that I pulled the plug. It was a light brown color. Now the actual question. It is my understanding that is how it should look when jetted properly. Is this correct? I really don't want to burn up a piston when I go out next weekend. I still don't know exactly what size big bore kit has on it. 300 or 330. I do know it is ported. I saw that when I pulled the reed valve. The compression seems pretty good when I kick it over. Haven't checked that yet either. I also run racing fuel(110 octane) at a 32:1 ratio. Thanks in advance for any input.

JkAss

 

its not accurate unless you're doing the plug chop procedure correctly and even that method isnt full proof. just because you pulled it doesnt mean its not running lean on top, especially if the last time the engine was running was at idle before you hit the off switch. make sense?

the correct procedure is to run it (not in front of your house. conditions are different in glamis [img]i/expressions/face-icon-small-wink.gif[/img] ) at WOT in 3-4th gear for a good 1/2 to 3/4 mile and hit the off switch. do not let it come down on RPM's with the throttle. leave it at WOT and hit the kill switch. pull the plug, and that is the way plug chops work. this is not 100% accurate, but its better than flipping a coin.

your jetting sounds pretty good as it is. the needle that comes in a Air Stryker is probably a little lean in the mid section. I have a great jetting table that is a tad on the fat (rich) side for all big bores. It has pilot/needle/main jetting sizes that goes with big bore size/pipe/porting/carb. very good.

 

How would I get a jetting table, like the one you are referring too?

 

I'm trying to post it on my gallery but the site is having problems or its my computer. either way, if i see the error again im going to kick the computer in the nuts.

what's your email address. ill email it to you.

 

also, the table recommends a 188 main. with your setup.

you might look at a swing arm or a pipe for your next mod. your list is looking good though. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Actually I bought a used swingarm on ebay for $30.00 and a guy at work is stretching it 4" for me. I problably wont have it on tell next season though. He is real busy and is going to work on it when he can. The high rev pipe from ESR, that you recommended will be the next purchase someday. I'll PM you my email.

 

shouldve hit me up, i have a 86 swing arm in the garage just sitting there. PERFECT condition. mike330r gave it to me so im not even about to charge anyone for it.


btw, if you have a digital camera, snap some photo's of your engine/cylinder. if its a stock cylinder, chances are its not over 295cc's. you dont want one of those from what i hear anyways. [img]i/expressions/face-icon-small-smile.gif[/img]

 

OK, it also has a coolhead on it. It has some engraving on the side. hopefully the pics will show it clearly.

 

Its a 295...

 

How can you tell? What characteristics tell you that? Is that a stock cylinder head? Is a 295 the biggest a stock one can go?