250r carb on blaster

[burndout]

Would like a no bs thread on 250r carbs. Need to know what's needed to run the carb. Will be on a 240bb, porter whith power pros pipe. I will be getting a carb rebuild kit and I know jetting is needed, anything else like the rubber boot needed? Will the stock thumb throttle work? The air intake tube from box to carb will be custome made so im not worried about that. Its a 30mm keihin PE.
Please no "this wont work" posts, I know it will.

 

[sicivicdude]

It's about getting the pieces which have the greatest gains (usually for the least amount of money) and folks already know something about. The most popular carb swaps are the PWK series, the PJ series and the mikuni TM series because they are common and people have experience with them. If you're determined and don't mind finding your way out of the dark on your own, just about any carburetor will work... Heck, a carburetor of a riding lawnmower could work but it won't be optimal and no one will be able to help you figure out any problems with it.

The "tors eliminator" cable for the stock carburetor works with MOST keihin carburetors. If you prefer twist throttle, vito's sells a kit with the same carburetor end on it but a twist kit.

The incoming fuel may be a different size than the stock carburetor. Stock is 6mm (1/4"), the PWK's are 8mm (5/16") but not sure what the PE uses. A banshee petcock has the 8mm outlet if it is the larger.

I stuffed my OKO 30mm carb into the stock intake. I know a 33-38PWK uses a larger engine side connector which can be had fairly cheap. UPP makes them for that size carburetor if the PE uses a larger carburetor body.

Depending on the shape of the float bowl a reed spacer may be required. My OKO 30mm needed one.

If you are making the airbox, you don't need to worry about that side of it, just make it to fit whatever the carb has already.

 

[slickerthanyou]

I have a 30MM oko Kiehin knock off, ans i was able to use the stock intake boot. Yes it will work, but a larger carb would work better -performance wise-. Yes the stock thumb throttle will work but you will need a different cable. Unless you have the cable that came with the 250R and it is thumb throttle.

 

[slickerthanyou]

Depending on the shape of the float bowl a reed spacer may be required. My OKO 30mm needed one.

Good call bro forgot about that one! yes i too have a spacer to clear the clutch arm!

 

[burndout]

Thanks guys, this is exactly what I am looking for.

sicivicdude - great info, I never thought about the petcock.

I know some of you guys are running this carb, anyone care to chime in on the issues you have had to cover come? Or better yet have a PWK or PJ for sale?

 

[sicivicdude]

I have a 26mm PE carburetor on a 1982 Honda ATC 185S. I didn't get nearly as deep into it as I did into the blaster carb. The engine also isn't as picky as the blaster either....

The slightly later model 250R's used the 34mm PJ carburetor (which was finnicky in its own right with the idle/choke combo lever) but is still a little more mainstream of a modification to the blaster.

I believe YZ125 and YZ250's in certian years used PWK35's. They include a throttle position sensor akin to the TORS system but it's not needed to run on the blaster.

If you are looking for tuning help on the PE 30, you will probably have better luck on 3wheelerworld.com

 

[burndout]

Ok, I decided to snap a pic of the side of the carb, I cannot locate the model number online any where - on the side it has PE and 30awvf below that.

On the smaller side it measures 31mm, according to Keihin the closest is a 30mm and it would be a 20, 22, or 24mm found here: Carbs

I am a little confused as what carb this is, maybe the guy I picked it up from was wrong in saying its for a 250r?

 

[York Racing]

Haha I can't figure out which is older, the carb or the keyboard. lol

 

[sicivicdude]

The inside diameter of the carb throat on the engine side is 31mm?

I didn't know they made anything other than a 26mm PE (only because I've got one)

I don't think the 30 is the model number... only the serial number.

 

[245stroker]

If that carbs for a 250r then it must be for an old air cooled trike and not the liquid motors. Honestly if your running a ported 240 bbk, don't bother with that carb. Either get yourself a 34mm pj or 35mm airstryker

 

[99LRDblaster]

Keihin made an old 30mm PE carb. I think they are older versions of the PJ carbs and were mostly used on dirtbikes way back in the day.

 

[sicivicdude]

The PE series carb isn't related to the PJ series but they are similar (like how a PJ and PWK are similar but not related)

I've never seen one and have no idea what a 30 mm PE carb might fit, but older model dirtbike makes sense.

I say give it a go and let everyone know how it works. Just make sure you take a bunch of pictures and document everything.

 

[99LRDblaster]

Carbs

 

[burndout]

Well I just got the top end back from the shop tonight, everthing is looking good, went ahead and chambered the head since most everyone said it would be the best way. Had the shop take a look at the carb and he also said the carb was older than dirt. Looks like I am gonna be going with the stock carb with a jet kit, atleast until I get the cash up for a PWK or PJ, thanks for your input with this guys.

ps - the keyboard, does it look old? Its a brand new laptop with spaced keys for us that know 3 days in advance when its gonna rain... I hate the 'pain weather radar' from riding since I was 4yrs old but Im sure Im not the only one.

 

[sicivicdude]

Don't run that 240bb kit with the stock carb long or hard. The 26mm Mikuni carb doesn't provide enough air or fuel to run a 240BB kit well. Maybe an off the shelf vito's but even they recommend a larger carb.

Troll Ebay and Craigslist for someone with a 250R or 125 dirtbike carb. They're PJ's or PWK's and sometimes you can pick one up pretty cheap that way.

 

[burndout]

Don't run that 240bb kit with the stock carb long or hard. The 26mm Mikuni carb doesn't provide enough air or fuel to run a 240BB kit well. Maybe an off the shelf vito's but even they recommend a larger carb.

Troll Ebay and Craigslist for someone with a 250R or 125 dirtbike carb. They're PJ's or PWK's and sometimes you can pick one up pretty cheap that way.

Good idea, I'm gonna be getting into the bottom end this weekend, I'll check into the Ebay, aint crap on craigslist.