Planet Minis

crowdlg · 08-23-2007, 09:31 AM

Has anyone here built an xr50 with a cheap 4 speed trans?My buddy just blew up my 88cc xr50 and i am going to rebuild it now and would like to upgrade to a 4 speed.i have some old ct70h,sl70 and atc70 blocks sitting around.can i use any of the shafts or gears to make a 4 speed.i know the old bikes used bushings on the block instead of bearings.or can anyone tell me of an aftermarket set that has worked for them that is not in the kitaco/takagawa price range.another idea is if some of the shafts or gears in a 4 speed trx90 may work.maybe could just buy a few new parts from honda to make one work.any ideas or info would be appreciated.

Z · 08-23-2007, 09:40 AM

Dave,

You can put a 12V 4 speed into 6V cases, but you can't put a 6V gearbox into 12V cases without lots of work due to the differences in the kickstart shaft.

AHP sells a 4 speed. I'd opt for one of those.

reynolds_brad · 08-23-2007, 10:21 AM

I had a friend who put a old honda 4 speed in his xr50 cases. lol

check this thread out. http://www.planetminis.com/f14/why-n...4-a-15717.html

fatcaaat · 08-23-2007, 10:32 AM

I have done this modification in the past and have not experienced any problems. The other option is to buy a set of cases from DRATV. Nowadays, you can almost buy a new engine for $150 from some vendors and get a complete bottom end. Lots of options depending on what your wallet can do or what you know about the workings and interchangability.

BTW, Dave, my buddy and I did a 180 mile run from Marshall to Culpeper, down to visit the Moonshine guy, and back up and around through Warrenton. We also did a small segment of skyline drive. We did this last weekend...me on my honda CL70 and him on my CT70.

If you EVER want to get together and do a run around Virginia...drop me a line. I am out that way quite a bit.

50-50 · 08-23-2007, 10:40 AM

Another gear would be nice. I'll have to look into the AHP tranny.

crowdlg · 08-27-2007, 08:10 AM

thanks for all the help.i might open a few bottom ends and see what will mock up when i get the xr engine apart.thoes pics of the broke 4sp that was motarded gives a little fear but im sure that bike was abused to no end.

08-23-2007, 09:31 AM	#1 (permalink)
crowdlg PM Newbie Join Date: Jan 2006 Posts: 85	What old honda 4 sp trans will fit xr50 cases? Has anyone here built an xr50 with a cheap 4 speed trans?My buddy just blew up my 88cc xr50 and i am going to rebuild it now and would like to upgrade to a 4 speed.i have some old ct70h,sl70 and atc70 blocks sitting around.can i use any of the shafts or gears to make a 4 speed.i know the old bikes used bushings on the block instead of bearings.or can anyone tell me of an aftermarket set that has worked for them that is not in the kitaco/takagawa price range.another idea is if some of the shafts or gears in a 4 speed trx90 may work.maybe could just buy a few new parts from honda to make one work.any ideas or info would be appreciated.

08-23-2007, 09:40 AM	#2 (permalink)
Z 5th Gear Member Join Date: Sep 2003 Location: KANSAS Posts: 8,540	Re: What old honda 4 sp trans will fit xr50 cases? Dave, You can put a 12V 4 speed into 6V cases, but you can't put a 6V gearbox into 12V cases without lots of work due to the differences in the kickstart shaft. AHP sells a 4 speed. I'd opt for one of those.

08-23-2007, 10:21 AM	#3 (permalink)
reynolds_brad Advertiser Join Date: Dec 2003 Location: San Francisco, CA Posts: 2,719	Re: What old honda 4 sp trans will fit xr50 cases? I had a friend who put a old honda 4 speed in his xr50 cases. lol check this thread out. http://www.planetminis.com/f14/why-n...4-a-15717.html __________________ pecore nere ufficiose Motoshop Z - Honda50.com

08-23-2007, 10:32 AM	#4 (permalink)
fatcaaat 3rd Gear Member Join Date: Sep 2004 Location: Arlington, VA Posts: 3,778	Re: What old honda 4 sp trans will fit xr50 cases? I have done this modification in the past and have not experienced any problems. The other option is to buy a set of cases from DRATV. Nowadays, you can almost buy a new engine for $150 from some vendors and get a complete bottom end. Lots of options depending on what your wallet can do or what you know about the workings and interchangability. BTW, Dave, my buddy and I did a 180 mile run from Marshall to Culpeper, down to visit the Moonshine guy, and back up and around through Warrenton. We also did a small segment of skyline drive. We did this last weekend...me on my honda CL70 and him on my CT70. If you EVER want to get together and do a run around Virginia...drop me a line. I am out that way quite a bit. Last edited by fatcaaat; 08-23-2007 at 10:34 AM.

08-23-2007, 10:40 AM	#5 (permalink)
50-50 3rd Gear Member Join Date: Aug 2006 Location: PA Posts: 1,844 My Mood:	Re: What old honda 4 sp trans will fit xr50 cases? Another gear would be nice. I'll have to look into the AHP tranny.

08-27-2007, 08:10 AM	#6 (permalink)
crowdlg PM Newbie Join Date: Jan 2006 Posts: 85	Re: What old honda 4 sp trans will fit xr50 cases? thanks for all the help.i might open a few bottom ends and see what will mock up when i get the xr engine apart.thoes pics of the broke 4sp that was motarded gives a little fear but im sure that bike was abused to no end.

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