My KX1R project.....

falconman · Post by **falconman** » Tue Feb 09, 2010 6:38 am

Another update. Finally got the crank together for balancing. I made a jig to index the crank halves to make it easier to assemble. Phasing came out perfect on the first try. $\:D/$ Hopefully I'll get it back later this week. I should have time to break out the tig and weld up the cases while I'm waiting.

Ready for balancing!

Speaking of balancing, I understand most of what you guys are saying. Smithy, I understand what you mean by more weight off the side opposite the pin but keep in mind the KX piston is half the weight of the RZ piston and the rod (while the same ctr to ctr length) has a smaller pin size also. There is alot of weight being reduced on the pin side, just at the piston. Not sure if that is the same though. But again, not my problem. The guy doing the balancing has that task. I just write the check.

Oh, KR-1R, you are correct about the balance weights. Dime a dozen here at any corner grocery store. If you need any let me know. Might be a problem posting them though.

Bikemike · Post by **Bikemike** » Tue Feb 09, 2010 9:43 am

Whoa!!- That's a geiger counter?
EEEEK!

falconman · Post by **falconman** » Tue Feb 09, 2010 9:48 pm

Sure is! Doesn't everybody have set?

Got this at a military surplus for $50. Nice little cold war relic that may be useful again soon.

TwoStroke Institute · Post by **TwoStroke Institute** » Wed Feb 10, 2010 1:58 am

Jim has the balancer got a % in mind? I like your press tool, I made a similar one for 50.6mm stroke cranks with 3 holes 0 ,90 and 180 deg.
Tungsten slugs are cheap also.

falconman · Post by **falconman** » Wed Feb 10, 2010 5:10 am

He didn't say. He was going to give it a spin later this week to see where it's at then call with recomendations. I'll post what he says here to figure out if it's best to stay with 180 or go 90 and lose the balance shaft.

mj43 · Post by **mj43** » Thu Feb 11, 2010 12:44 am

That is looking good Jim

falconman · Post by **falconman** » Wed Feb 17, 2010 10:20 am

Back from the balance shop!! Got the crank back today. Not the way I would have done it but it better work.

Total was $440. He couldn't use the heavy metal I provided, said he didn't have a drill large enough but probably more like he wouldn't get enough money out of me if I supplied the stuff. Used 58% for the balance. I'll post a pic of the balance card after I get it scanned. After I had got it together to take in I found that the first machine shop had ground the primary gear part (where it presses on) off center. Going to cost at least another $150 to fix that.

As soon as I find some crank bearings I'll have this together. While I'm waiting I'm going to put my spare stock crank in the cases and figure out what rod would be needed to use the stock crank with the kx cylinders as most people would have a hard time funding this crank!:roll:

[/img]

pablo · Post by **pablo** » Wed Feb 17, 2010 3:59 pm

Falconman you loose me

I think I've caught up and then you loose me again

I am trying though......... Honest

falconman · Post by **falconman** » Thu Feb 18, 2010 7:43 am

Just some notes: I weighed the cranks, stock and the one I'm making. Complete and ready to drop in the stock one is 5.0kg (11lbs) and the modded RZ is 5.5kg (12.14lbs). Pablo, if you want the title that bad you can have it.

I'm going broke!!

falconman · Post by **falconman** » Fri Feb 19, 2010 4:24 am

Better get going pablo, I'm widening the gap!!!!

Why cheap machinists aren't so cheap.

Found a flux pocket in the weld he made to fill in the key slot. Now I have to cut out the entire weld to redo it since it can't be trusted.

TwoStroke Institute · Sat Feb 20, 2010 12:34 pm

You can try late model RM 125 , KTM 125 and TZ125 (54mm bore) they have 110mm rods with 28mm big end eye and 19mm small end for the 15mm gudgeon pin.

Sheik Yerbouti · Post by **Sheik Yerbouti** » Sat Feb 27, 2010 5:22 am

Christ what did he weld it with? A coat hanger and a car battery?

pablo · Post by **pablo** » Sat Feb 27, 2010 1:19 pm

Sheik Yerbouti wrote:Christ what did he weld it with? A coat hanger and a car battery?

falconman · Post by **falconman** » Sun Aug 29, 2010 11:20 pm

After about 6 months of waiting I will be going to get my crank parts back. The end throw needed to be hard chromed and reground on centers to fix the offset. The shop just keeps making excuses so time to find a new shop. Once I get the crank done the rest should go quickly as I will be doing most of it myself. I just have to have the crank to get the dimensions for the next steps.

falconman · Post by **falconman** » Tue Aug 31, 2010 8:26 pm

Wow. Went to the machine shop to get my parts back and they were actually done! $\:D/$ $250 to fix the offset and add a pin so the primary gear won't spin on the crank. I'm currently getting my KR ready for the Sept race so I won't have time to play with this for a couple weeks. But now I can do final assembly of the crank and complete this project in about 2 months. [-o<