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4mm Offset Crank Pin For Stroker

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I have a 4mm offset crank Pin that I got from Greenhuman for stroking my CRF230. It adds a total of 8mm of stroke to the 230 and uses a TRX250 rod to adjust for the length. I have a local machinist friend that was going to help me set this up, but he is no longer able to assist. This is a great project with lots of potential for the 230 but I am not going to be able to do it. If anyone is interested, send me a pm and I can provide the details of what is involved along with the offset pin for a good price. Ricky Racer is working on the same project so more to come for sure on this. 

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If you were looking to find a crank shop that really does a great job....

I can wholeheartedly recommend Crank Works of Arizona for any and all crank modifying services

 

 

 

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Thanks Mixxer, I just need someone local. The assembly process requires the pin to be installed in half of the crank, then the rod. This has to be installed into case with the transmission gears so the big end of the rod can be clearanced. Then the other crank half pressed on. It would be prohibitive for me to ship these parts back and forth through this process. Disappointed that my local machinist is out, this seems to be a fairly inexpensive investment to get lots of extra cc's.

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I really want to start on mine BUT keep riding it as the weather is so nice. 95° in the mountains today. 

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Ohhhhh.... I see now jeffrow... I was unaware of the clearancing step before final assembly of the crank...

You do have a problem now...

In any event, I would have the final step done by Crank Works... Trueing, balancing, and if need be, welding... All my experience with.them and custom crank work has been excellent... Custom strokers for high output applications have been smooth , well balanced, reliable, vibration free..

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I have a 4mm offset crank Pin that I got from Greenhuman for stroking my CRF230. It adds a total of 8mm of stroke to the 230 and uses a TRX250 rod to adjust for the length. I have a local machinist friend that was going to help me set this up, but he is no longer able to assist. This is a great project with lots of potential for the 230 but I am not going to be able to do it. If anyone is interested, send me a pm and I can provide the details of what is involved along with the offset pin for a good price. Ricky Racer is working on the same project so more to come for sure on this. 

 

 

Send your crank rod and pin to Terry Miller

I have spoken to him very recently and he knows exactly what to do and how to do it.

If you use one of his Wossner rods, not only will the rod be stronger than the TRX rod, the piston will not be sitting down .020 below the deck and your deck height will be at .000 which is perfect.

Also your rod (or what ever rod you end up with)will be required to be clearanced (modified) so it will not have interference (collide) with third gear main shaft.

 

Terry has been doing this for years, he is the man that can do the job.

He is very busy helping out with massive forest fires in Oregon, So be patient.

 

I have always heard great things about "crank works", I'm sure that they can do the job also.

I definitely do not know if they are aware of notching the rod for gear clearance?

But I'm confident that they can figure it out also.

Terry will do all that for you automatically

 

Suggest to pick up a used crank on E Bay so you can keep riding while it's being worked on.

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I would totally go with Terry Miller... 

Guy, I just didn't know Terry was available so I threw crank works out there.

 

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Thanks for the replies...this was supposed to be a do it yourself job while working with my machinist friend that has the tooling to tackle this job, and also on the lesser side of expensive. I paid $125 for the offset pin and can get the TRX125 rod for $100. Being able to drive 5 miles to do the required pressing and clearancing would have been a real winner. Unfortunately I lost my contact. My loss is your gain..any one that wants to try this 4mm (8mm) pin I will give you a good deal.

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Sorry it did not work out for you.

There is a guy on the XR200 page talking about stroking his XR crank. The plus 4 pin is perfect for him then he can use a CRF230 piston kit which is 4mm lower than his Xr piston. Vulcanduro I think is his name.

Edited by greenhuman

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I have lots of details from Greenhuman on this process including some pics. The 4mm additional stroke from the pin requires a TRX250 rod that is 4mm shorter than the 230 rod. Basically, press the crankshaft apart and remove the stock pin. Then install the offset pin in one half of the crank with the rod, and Install this assembly into the case with the transmission gears. The big end of the rod needs a small clearancing to clear 3rd gear. Then press the other crank half on and align the crank. Done. It requires a press to dissassemble and reassemble, then the crank halves need to be aligned. I paid $125 for the offset pin and the rod is $100. Pretty inexpensive deal if you know a machinist. I will sell the pin for $75 if anyone is interested, just send me a pm.

IMG_1927.JPG

IMG_1933.jpg

Edited by jeffrow68
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1 hour ago, jeffrow68 said:

I have lots of details from Greenhuman on this process including some pics. The 4mm additional stroke from the pin requires a TRX250 rod that is 4mm shorter than the 230 rod. Basically, press the crankshaft apart and remove the stock pin. Then install the offset pin in one half of the crank with the rod, and Install this assembly into the case with the transmission gears. The big end of the rod needs a small clearancing to clear 3rd gear. Then press the other crank half on and align the crank. Done. It requires a press to dissassemble and reassemble, then the crank halves need to be aligned. I paid $125 for the offset pin and the rod is $100. Pretty inexpensive deal if you know a machinist. I will sell the pin for $75 if anyone is interested, just send me a pm.

IMG_1927.JPG

IMG_1933.jpg

That's a deal. I should get it and prep two rods when I do mine😁Then I would have a kit ready to go😎I will seriously think about it and let you know soon!

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18 minutes ago, bajatrailrider said:

Dam you guys I was hoping to see this project up and running. Someone do it.

Weather is to nice to stop riding!

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2 minutes ago, ricky racer said:

Weather is to nice to stop riding!

I agree we went on what I consider one of the hardest trails in baja last week. It runs along the ocean I drank 2 liters of iced electrolyte in first mile, lucky I had two spare bottles of electrolyte, and one qt extra water to pour on me. Also lucky only first 1.6 miles was hard part. My 254 stroker zero over heating even pushing it  , cant say same for rider. Leader of ride said I was oldest rider to ever finish ride. Or the not very smart oldest rider.

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8 hours ago, bajatrailrider said:

I agree we went on what I consider one of the hardest trails in baja last week. It runs along the ocean I drank 2 liters of iced electrolyte in first mile, lucky I had two spare bottles of electrolyte, and one qt extra water to pour on me. Also lucky only first 1.6 miles was hard part. My 254 stroker zero over heating even pushing it  , cant say same for rider. Leader of ride said I was oldest rider to ever finish ride. Or the not very smart oldest rider.

OK, got it, you drank two Tecate caguamas in the first mile while your overheating KTM drank all your water.  Good thing you had two extra Pacifico Ballenas while pushing the bike.  What were you stroking?

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15 hours ago, Baja Rambler said:

OK, got it, you drank two Tecate caguamas in the first mile while your overheating KTM drank all your water.  Good thing you had two extra Pacifico Ballenas while pushing the bike.  What were you stroking?

Baja Hooter koko again if you would stop the coronas your bike would get done. By the time you finish  your bike mine will need rebuilding. Stop posting get the bike done lets ride.

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2 hours ago, bajatrailrider said:

Baja Hooter koko again if you would stop the coronas your bike would get done. By the time you finish  your bike mine will need rebuilding. Stop posting get the bike done lets ride.

The boys are planning a 1,000 mile adventure in oct., but may not meet your comfort standards, we're camping on a different beach every night.  One-legged-Larry is driving the chase truck.  You should go, Needle.

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That's a deal. I should get it and prep two rods when I do mineThen I would have a kit ready to goI will seriously think about it and let you know soon!

I had to clearance in two different spots for two 4mm and two 6mm cranks.
But I removed much less material and allowed only
.030 clearance in those two spots.
That's a deal. I should get it and prep two rods when I do mineThen I would have a kit ready to goI will seriously think about it and let you know soon!

I had to clearance in two different spots for two 4mm and two 6mm cranks.
But I removed much less material and allowed only
.030 clearance in those two spots.
  • Like 1

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