Can any one give me some base line jetting specs for a 74 KTM 250 mc , I'm running a carl cranke pipe and the bike revs to the moon , but I'm up to a 190 main from the 165 stock main jet , and I'm afraid I might be chasing an air leak with the jets, the bike runs perfectly just lean . It has the 36Bing and a B8 NGK plug. Thanks much Dennis
Dennis, I don't have an answer to your question, but where did you get the Carl Cranke pipe? I'm building a 250 and am curious.
Glenn
Quotequote:
Dennis, I don't have an answer to your question, but where did you get the Carl Cranke pipe? I'm building a 250 and am curious.
Glenn
Glen I have a genuine Cranke pipe that came with the bike , but my friends at Maico Only,Eric and Steve make a repro Cranke pipe to exact specs their work is flawless and the price is right their number is 909-947-1121
Dennis, thanks for the info.
I'll give them a call.
Glenn
Guys,
I called Maico Only and talked to either Eric or Steve, and inquired about pipes.
They currently can do the Carl Cranke spec pipe, and it's $225 plus tax, title and destination. I also asked about stock spec pipes for the '74 250 and 400, and he thinks he can do them, too. If he can get the specs for the stock 250, he can build them right away. He's trying to get a 400 (that isn't bent up) into his shop so he can make sure the 400 pipes are fit properly. I'll send him an e-mail confirming what he's told me and so he can reply when he knows anything. He said three guys are already waiting for the 400 pipes. His holdup is getting a good bike in the shop to use for fitting.
I'll keep you posted on this lead.
Sorry I didn't respond earlier..I was not sure on the main jet. Still not..I spoke with Bobby but forgot to ask. I am still confident though that a 190 main is not way out of line with an aftermarket pipe on a 250. That was in Texas at sea level. Plug readings were good. Seems like bike didn't need but a few throttle blips to clean out though. I just attributed this to the Bing carb. I never liked revving the snot out of it in nuetral with the heavier flywheels of a Penton anyway-just made me nervous. I hope this gives you an idea ( I think you are in the ballpark). If you are unsure -you shuold do a leakdown test. Thanks, James
I have bike parts in the kitchen cabinets where most people have dishes..
To all:
Has any one of you had Maico Only build a 250 Cranke pipe? I talked to them today and they said they built one, but never got any feedback from the buyer as to how it worked (or if it worked) with stock porting.
Does anybody have any experience with a Cranke spec pipe used with a stock ported cylinder?
Glenn
Dennis- Everyone wants your pipe, but no one answers your jetting question... Stock jetting for Mod 54 Bing, 36mm per thr 8/74 Operation Manual -- 165 Main, 35 pilot, 283 needle jet, clip in 2nd position (middle). The summary "Technical Data" in that manual for the 250 says 40 pilot. The 7/76 trifold brochure said 165/170 Main, 50 pilot. Mine runs good with 165/35, take your pick. Mac