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1974 honda cr125 dg exhaust clearance

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Hi there, 

Sorry if this is a silly question but I have just fitted a dg ehaust to my 74 cr125 and just wondered if any one elses is quite tight to frame and sump plug?

If i push the front of the pipe against the springs (side to side) it can hit the frame and touch the sump plug. 

Is this right? Any advice or pics really appreciated.

Thanks Kirk (uk)

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I have a '77 CR125 which is very similar to your '74. Mine has a Pro-Form pipe and the fit is pretty much how you describe yours. There should be a third spring which keeps the pipe tucked in under the bike. If it's missing, mine was, the foot peg mount will rub a hole in the pipe. That's the only place my pipe has been damaged by hitting the frame. All the other damage is due to impact with the ground. I've since swapped my motor for an MR175 so the fit of the head pipe is not perfect either.

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Perfect - thanks for the reply - mine has only two springs - I will take another look today.

 

Thanks again - Kirk

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Ah yes - nor does mine. 

Looks like the original had 4 springs - not sure where the fourth would attach too..

Mine does hit the side of the frame slightly and can be pushed over to the sump plug - Ill use it as it is and report back if any damage!

May I ask why the engine swap? I have a MR175 as well (and a spare engine..

 

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For spring attachment points, a clever friend bent some old drivetrain chain side plates and welded one flat part to the pipe. Since the plates were bent in the middle, the non-welded half stuck up, allowing it’s pin hole to accept the spring. It worked great and solved my pipe attachment issues.

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4 hours ago, Kirk123 said:

 

May I ask why the engine swap? I have a MR175 as well (and a spare engine..

 

My 15 year-old son has raced the CR in vintage mx for two years. It's his first 2-stroke after riding 4-strokes since he was 6. The transition from a bike with lots of bottom-end torque and a wide power-band to one with virtually no bottom-end torque and a narrow power-band has been difficult. The 125 motor has also been plagued with an endless supply mechanical gremlins.

After looking at various options I found a stock MR175 motor with a fresh top end. I dropped the 175 motor into the CR chassis and swapped over the ignition, carb and pipe from the CR. So far it's performed better than expected. With only a couple jetting runs and a few practice laps, my son raced last weekend and ended up second in both classes against bigger bikes. He liked the fact he didn't have to fan the clutch coming out of the corners. The only downside is the wide-ratio MR 5-speed. Anything above 3rd gear is useless so a future mod will be to drop in the 6-speed from the CR motor. Still need to fine tune the jetting (Mikuni VM32 carb) and maybe try a different pipe.

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Edited by vintagemx
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I had a '75 CR125 with a DG pipe , I only remember the springs at the cylinder. You could move the pipe around a little.

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