Vintage Dirt Bike Q & A

What series Keihin carb was factory installed on the early CR250M? Was it a PE or VM? I need to find someone that carries a replacement needle jet

_________________
73 Z1 900 kaw
76 TL250 honda
76 cr250m
82 CB 900c honda
83 V65 Magna
84 Eddie lawson replica Euro
82 RM465
82 RM125
85 VF1000R
74 MX360
75 MX400
79 YZ400
74 cb550K

Is it the needle that you need? Keyster part# kh-0138 will have what you need. I got mine from Rusty Riders. 740 522 8875

I have a NOS jet needle. What I am looking for is the needle jet. I have a bad problem with the engine loading up a lot just off idle To the point I'm blowing out raw fuel from the pipe. I went from a 148 main down to a 140 jet. It reduced the amount of raw fuel but still un-useable. I had no idle adjustment at all. I have replaced about everything except the needle jet. I have a n.o.s. 679B carb I installed and it ran grate. There not much left to replace. I suppose the choke may not be sealing and letting excess fuel by.
I didn't mention, I'm referring to a 76 cr250m

_________________
73 Z1 900 kaw
76 TL250 honda
76 cr250m
82 CB 900c honda
83 V65 Magna
84 Eddie lawson replica Euro
82 RM465
82 RM125
85 VF1000R
74 MX360
75 MX400
79 YZ400
74 cb550K

I have not seen any kits yet that come with needle jets. I do alot of carbs and have never had to replace one. Pull out the choke plunger and look at the end. If the rubber end is torn or deteriorated that needs to be replace. I have never seen one go bad on a Keihin; Bing carbs are notorious for this. I had exactly the same problem last week on my 75 Cr 250. This is my third resto on 1975s and two out of the three ended up with new mikunis. Did u ck float for leaks. What about height? Factory book says 19mm. I'm betting you carb body is cracked or just plain worn out. I never did find the problem and I spent days checking and adjusting. Put the original carb in a box and get a Mikuni vm. You will be happy you did. Good luck

Nice pics by the way. Ck out the bike galley on the home page.Mine is the only 75 Cr 250

Thanks, thanks for all the input. I will check the choke plunger and see if I can get air/fuel to bleed by.

_________________
73 Z1 900 kaw
76 TL250 honda
76 cr250m
82 CB 900c honda
83 V65 Magna
84 Eddie lawson replica Euro
82 RM465
82 RM125
85 VF1000R
74 MX360
75 MX400
79 YZ400
74 cb550K