Vintage Dirt Bike Q & A

Just wanted to pass on a positive experience. I had to send the many-times-overbored cylinder from my '74 out to be resleeved. I wanted to start with the stock 70.0 mm bore so I sent the cylinder, head, Wiseco piston and rings. When I got everything back, I had a "good as new" top end. The ports were blended better than new, they bored and honed the cylinder to match the supplied piston and they surfaced the case and head gasket areas.

I installed the new top end on my just restored bottom end and performed a leak-down test. The engine lost less than 1/2 psi in three minutes which is as good or better than my current race bikes.

Racers Toy Store did a first rate job for a very fair price. I will be turning to them again when I start the restoration on my '79.

During the course of this restoration (almost a year now), I have dealt with a number of shops and vendors. The list is pretty short for the ones that do good work and/or are reliable and pretty long for the ones that aren't. These guys are on the short list.

dogger

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1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

+1 many times over.

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF

Just curious do you have a stock rod kit or the 4 mm longer one. ( I believe the longer ones are 75-76 rod kits)

I got lucky and found an NOS crankshaft still sealed in it's original packaging - so it is a stock rod.

When I said "many overbores", the end gap on the stock size rings fitted into the bored out cylinder was 2.0 mm! I'm not sure, but I think that is ten times the service limit. I don't know how much over you have to be to get a gap that big. It's amazing how much abuse these engines can absorb and still run.

dogger

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1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

Dogger,

I see we share some of the same taste in bikes, to bad your not around Tulsa, we could hook up and ride.

Can you tell me if Racers Toy store does trannys for Elsinores. I have one in need of some work and might be lookig for a place to send it?

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C Bly

74 CR 250M
74 CRF 175
75 XR 75
77 ProFab Aberg HL500
97 Montesa Cota 315R
2003 CR500 AF
2004 CRF 450

C Bly,

You need to load up your trials bike and head down here in the late spring. The Trals Training Center is
a couple of hours from here and they have some of the best trials runs for all skill levels in the country.

I started riding trial to improve my balance and reflexes for motocross and now ride it just for fun. I've
been eyeing one of the new Montessa four stroke bikes to replace my "Dougy Lampkin Replica".

As far as your tranny rebuild goes, Racers Toy Store does tranny mods so I suspect they could handle a
rebuild. Here is the link to there site http://www.racerstoystore.com, give em a call.

Out of curiosity, what is wrong with your tranny? I just finished rebuilding mine and it was surprisingly easy.
I was able to find some NOS parts like shift drum, shift forks, snap rings, thrust washers and springs from
Honda. I bought a complete set of low use '76 gears off of Ebay then I replaced the bearings and seals and
bolted it back together and it runs and shifts like new. The only special tools needed are a case splitter and
dial indicator to check run out and lash. This was my first ever bottom end rebuild. I have always sent my
motors out to places like Tom Morgan Racing or Pro Circuit to make them race ready, so I was in uncharted
waters so to speak.

If you don't want to mess with a complete rebuild yorself, you might want to just split the cases and inspect
everything to get an idea how much work needs to be done and what parts need to be found before sending it
out. You will need to send those parts along because I doubt most shops will have them on hand. Another
shop I've heard good things about is John Astleford Company or Jastco. Here is the link to them:
http://www.jastco.com/jacotop.html. They also come highly recommended.

Whichever route you choose, good luck with it. Personally, I have found the parts searching, the "never tried
before because I was too chicken" mechanical challenges like bottom end, wheel lacing, suspension rebuilds
has been a blast and I can't wait to finish this one and start on the next.

dogger

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1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R

cbly: I'm in Tulsa. Love to ride with sometime. My son-in-law just moved to Illinois and my other riding buddy lives in Amarillo.

Shoot me a email, I am away on a project at the moment, should be back in town around the 18th, I have back surgury coming up @ the end of the month and will be down for a good 6 months, would really like to get one good ride in before that. Have you ever been to McCurtain coal pits? Its a little bit of a drive, but some kinda fun.

mailto:cbly@inservusa.com

Hey Dogger,

My tranny has shifting problems, it will shift thru 2nd when the bike is not running, when running it wont shift past 2nd. everything else seems fine. I really have no bussiness trying to split the cases, I tried this some years ago and wound up with a basket case. Anyway as far as the vendor that has it, Id rather not say, I just hope that it gets done pretty quick, kinda want to get the motor in the frame while I still can. I have had a blast on this bike, first time restoring a vintage bike, I already have my second project waiting, I am going to build a HL500 replica out of a 77 tt500, I can hardly wait. And if I ever get over your way I will load the Cota and look you up.




Later dude

C.Bly

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C Bly

74 CR 250M
74 CRF 175
75 XR 75
77 ProFab Aberg HL500
97 Montesa Cota 315R
2003 CR500 AF
2004 CRF 450

I've split mine many times, with good results. If you want to try again, let me know. I have a case splitter etc.
I would love to go to McCurtain sometime, but it will probably be early spring until I can get a hall pass for that trip, so we'll wait until you heal up. I'll send you an e-mail.

From what you described, it sounds like your bike won't shift under a load. My guess is something is moving that is out
of tolerence (mainshaft, countershaft, shift drum, shift fork, etc) from bearing wear or simply worn out causing the
tranny to bind up and not shift past second. A competant shop will have you up and running in no time.

Let me know what you find out and good luck with the surgery.

dogger

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1973 CR250M
1979 CR250R
1993 CR250R
2008 CR500R
2009 CR250R