Vintage Dirt Bike Q & A

I am stymied. I bought a replacement throttle cable for my MT250 because I want to restore using the oil pump instead of needing to mix. When I put the new one on and started the bike, it immediately went to redline and so I thumbed the kill switch.

I took the new cable off to compare it with the old one (which works perfect for the throttle but has the nub cut off for the oil pump). It appears that when pulled fully out on the throttle slide end, the free cable (the pulling part) was about .4 inch shorter than the old one was. So, I proceeded to trim back the rubber and metal sheathing of the cable casing to make it at least as long as the working item.

I put the new one back on, making sure that the adjustor on the top of the carb was all the way in, and fired the bike back up expecting it to idle. No such luck. It jumps to red line just as it did before mod'ing the cable.

Can anyone tell me what I'm missing here? Why can't I get this thing to work right?

Are you sure that the slide in the carb is rotated to the right position so that it can drop down to its closed position?
The slide cutaway faces the rear.
You might not have it in the right place and it is being held wide open.

That must be it! I was just being lazy by not taking the complete carb off the bike so I couldn't tell what position the slide needed to be in. Thanks for the help!

could someone please enlighten me in regards to this oil pump deal? no mixed gas? huh? can this be done to any 2 stroke?

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2000 XR600R
1979 XR200R
1975 MR175 Elsinore
1987 Husqvarna 510TE

It is OK for everything but some Suzuki motorcycles. Foggy memory but they injected the oil through the main bearing on something like the RM or TM 400.

From what I understand you can even modify the bearings on those to work with mix.

Rick

no,not just any two stroke.only the honda mt's had the oil injection,the same can be said about the yamaha enduro's and early yamaha mx models.suzuki ts and tm models and also some old kawasaki two strokes.most riders remove the oil injection
for weight reduction,oil foaming issues if the bike is being raced on a rough tracks or oil pump failure.some suzukis and kawasakis you cannot remove the oil injection because the oil is injected into the crankshaft bearings and removing the pump and running it on premix will quickly wipe out the bearings.

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(2) 1968 DT1 1970 RT1M,1970 DT1C 1971 RT1B Enduro 1974 MT250 1974 DT250A (2) 1975 DT400B 1974 DT100,1978 DT175
1975 CR250M1 1979 CR250R 1979 Kawasaki KZ400H1 Jesus is Lord!!

interesting...

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2000 XR600R
1979 XR200R
1975 MR175 Elsinore
1987 Husqvarna 510TE