Rokon Modifications Pages

Modifications made by Rokon Owners


Dave Richards
drichard@stny.lrun.com
Subject: ROKON fork mod.

For your modification list: don't forget about the day in 1974 when someone figured out that you could put compressed air into the top of a fork leg and it would increase the spring rate progressively and spectacularly improve horable working forks and make them into just bad working forks. All you have to do is drill and tap the fork leg cap for 1/8" "pipe" threads and screw in some air valves, sometimes called snifter valves at plumbing supply stores. About 25lbs in each side works wonders for the old 7" Beators, it seems to make the seals seal beter, and with the valve cores removed, you have a neat way to add fork oil without fighting with the springs.. Dave R.

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How to make the RTII and MXII rear suspension AHRMA legal

Does the MXII havelaydown shock like my RTII? (Yes...Editor)

If so you can make upper mounts very easy and it works almost as well with less travel. First measure the distance from lower shock mount to the subframe (where the seat mounts) with the shocks fully extended. This is so you can keep the ride height the same with the new upper mounts. Second draw a line from the middle of the upper mount to about 1/2 down therear subframe. It should make a triangle. Then take card boardand make template for both inside and outside. You should be able to reverse them for the other side. I then put the bike on a stand off the ground and left a stock shock in one side to get the right drop. I used 13.5" shocks. I then formed the plates with a pairs of crimps and vice. I used18 gauge sheet metal.The shocks are mounted at about 25 degrees inclination. I can give you the exact figure if you need it. I can put my protractor on it tomorrow.I then drilled hole on the outside plate for the shock. Then spot welded the outer mount on with the shock bolted to the plate. Next I fitted the innermount marked and drilled it. I then unbolted it and mounted the inner plate and spotted it on. Repeat the other side with the left shock in its mount and weld it up! I used Redwing chrome shocks with 100lbs springs and they work GREAT! This should not change the geometry. My bike works better than my Yamaha. Part of it is the way the clutch puts power to the ground.

Hope this helps! Brian Digitmstr@aol.com

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Dave Beck
mailto:dbeck@lanl.gov

I have a 1976 RT340 which has been road raced, motorcrossed, ice raced, Grand Prix'ed, and street ridden. Its priceless.
Will answer questions regarding clutch modifications for bare tire ice racing. This machine is famous in Colorado in bare tire class ice racing during the late 70's. Actually gets front end in the air leaving the line in "bare tire" class! I have no parts to sell.
e-mail:dwbeck@roadrunner.com or dbeck@lanl.gov.
thanks
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Dave Beck
44 Estambre Rd.
Santa Fe, New Mexico 87505
e-mail: dbeck@lanl.gov
BMWMOA, IBA


Wes Baker (I think)
WEBMJC@ix.netcom.com

Another Modification to Rokon:
A few years back I blew head gaskets 2x at seperate AHRMA races. The first time I just thought it was defective. The secound time I investigated. It was found that the torque wrench would click off but then would not click when making a check pattern. Upon dissassembly I found the small heli-coil was comming apart. I put in new of the same but in practice it also proved bad. Checked out Keen-serts and other things similar and was not satisified with the end result outcome to be. Anyway what I did was machinist drilled out the holes in the cilinder larger approx 5/8" threaded them, they catch the liner, locktited in stainless steel bolts, machine cut off flush with gasket surface, drilled and tapped the center of the SS bolts and now mount the head with a aircraft allen head bolt. Use copper coat on the gasket and let it dry first. End of all problems and a simple job to remove the head now for routine decarbon work and top end check. German alloy in 70s was poor quality (recycled). I dissambled approximatley 6 additional motors I had and found that all had defective heli-coil on at least one hole. Did this retro to all motors we currently use. Also regarding OIL. I use only Blendzal "Green" Lable (100cc)per gallon of high octane pump gas. Rokon Robin used some other Yama or Hondaline and did a nasty 4 point desert seize to his piston. Read the article in SMOG news letter 03-97 where Blendzal is discussed by a well known expert. I have used this since my first CZ purchase in 1971 they were refered to as SEIZE-E then, however mine nor any of my two strokes have ever seized up. Pluss it smells good like a dirt bike should.


Bradley Conway
mailto:bradcon@centuryinter.net

i am familiar with many mods and fixes.had some help while racing from factory thru laidigs bike shop in akron ohio and jim fogel(factory rider for enduro,2 day,&6 day competition).feel free to post this if i can help anyone.brad c.


Wes Baker
331 Longridge Drive
Vallejo, CA. 94591
707-553-2424

I got my first one (Rokon) in about 1989 for $25,oo. It did not take long to get it running however the main berrings holder was gone and the mains would roll loose like a roller coaster. I tore down this motor and replace the mains (3) and the fun began. While the motor was down I matched the transfer ports and drilled larger scavenge oil holes in the transfers to aid oiling to the mains. I used a motortool and carved a chevron type grouve across the transfer and enlarged the countersink opening into the transfer hole.I built a down pipe (real expansion chamber and tucked it in very nice under the frame. the bike was lots of fun to ride and i decided to race it in ahrma retiring the rickman montesa i was raceing.