Vintage Dirt Bike Q & A

What would be the best carb. to run on my CR125 1980? Looking to race this bike next season. It currently has the stock Kiehen. Thanks

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Terry Moody #48f
3x 74 Honda CR250M Elsinore
74 Honda XR75
73 Honda QA50
78 Yamaha YZ125E
78 Yamaha YZ250E
78 Yamaha YZ400E
79 Kawasaki KX250
79 Honda CR250R
79 Suzuki RM400
80 Honda CR125
2x 83 Honda CR480R
98 Kawasaki KX250

The stock Kiehen is a 34mm.
I have better luck with the round slide Mikunis. I run 34mm on my (3) 79 CR125s. I also have (2) 80 CR125s that I will start with the Mikuni 34mm.
These should be easy to jet and fast enough.

If you are an expert, and can WFO all around the track, then port and get a Mikuni 34mm carb opened up to 35-35.5mm so it will still fit in your intake tube.

Are you going to race CALVMX next year?

ALex

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One is not enough.

18 bikes? That's a full gate!

Forrest,
(3) of thoses were yours.

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One is not enough.

Yep, I do plan on racing CALVMX series and Ahrma next year.

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Terry Moody #48f
3x 74 Honda CR250M Elsinore
74 Honda XR75
73 Honda QA50
78 Yamaha YZ125E
78 Yamaha YZ250E
78 Yamaha YZ400E
79 Kawasaki KX250
79 Honda CR250R
79 Suzuki RM400
80 Honda CR125
2x 83 Honda CR480R
98 Kawasaki KX250

Would you mind sharing your jetting set up for those? Thanks...Van

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1980 Honda CR125R

On (2) of them I just used the stock jetting a 260 main I believe, One of the bikes has a DG head, every thing else is stock. I did lower the clip on the needle a notch or 2 when I was at the track. I only run these at the track. You do have to keep the motor on the pipe, but it hauls when you do.
The last one has a 250 main with every thing else stock. This is my practice bike.

The (2) 1980s are just being finished so I have not run them yet. Stock motors, so I will start at the stock 34mm and see how they runs.
Alex

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One is not enough.

Thanks Alex! Great info. I have a DG head on my otherwise stock '80. Will be getting a 34 mikuni soon ...Van

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1980 Honda CR125R

I'm running a 35mm Keihin off the 81 model.
I had to modify the rear most overflow pipe by curving it down and I took a couple of mm
off the face of the inlet end so the ridge in the inlet boot lined up with the carb groove.
Other than that a good fit still experimenting with the jetting but it goes really well.