The trusty Yam in it’s infancy with Fred sporting those Betor shocks,
what looks like a Ty80 tank, home made bash plate and the original
Yam front wheel

Fred Martinson from Wyoming, Master Trialsmaster of the Mosteller Cup and the Casper 3 Day
Spectacular, has been tinkling and fettling his much beloved and faithful Yamaha and as another
devotee to the marque I’m quite impressed with some of the mods even though I haven’t, as yet, had a
ride on the beast.

I first met Fred at the old Perris Trialsland on my first year on the Ahrma circuit. Fred and traveling
companion Bob Strohman had made it down from Wyoming while Brenda and I had come over from
Phoenix. Fred had his Yamaha in the back of his covered pick up and used a tiny wheel between the
forks for the transit runs and then replaced it with a Suzuki front wheel at the venue…. never quite
understood why but I expect that Fred found the braking action better. The Suzuki front wheel is much
like the Ossa set up and requires a lug to be alloy welded on the fork leg and Fred has done this quite
neatly while removing the top lug for the original Yamaha brake anchor.

One of the first mods, the added fork lug to take the Suzuki front wheel

Over the years I’ve noticed several improvements with footrest position and a few other neat items and
more recently the special billet yokes from Brian Crawford and the fat bars. Last time I saw Fred in
action the frame had been lengthened and the head angle steepened.

First attempts at the “back and down” pegs, functional but not pretty!

Modified top yoke to take fat bars and Gas Gas clamps

Oooooooh! now we are talking “bling” with the custom yokes and stem
from Brian Crawford…… beautiful!

Since then Fred has been riding the Tiger Cub on the circuit but back at the ranch the Yam has had
some other work done with a bigger motor from BJ Racing, I believe, and some swappsies from a later
model Yam to further improve the development. The front part of the frame is a TY250A, but now
sporting a 77 model swinging arm as with the footrest repositioning it is somewhat difficult to get the A
model stand to work correctly as it is on the frame and not on the swinging arm of the later models.
Fred has re welded his footrest hangers (much neater) and used some wide Gas Gas pegs and
removed the original stand bracket hence the need for the 77 swinging arm.

The Mark II footrest hangers with the wide pegs

Fred has added about 1.375 inches to the top tube, cut out the cross brace tubing that held the
somewhat worthless toolbox, steepened up the head angle but with the increased frame length not
reducing the original wheelbase and then added some strengthening side plates where the top coil
can now be bolted on.

A test run with the lengthened frame at Donner 2008

An all new WES system replaces the first attempt with a Miller mid section for the exhaust and Fred has
gone for the same system I use with the UNI podded air filter. On mine I drill out the air box rivets and
then retain the lower mudguard system which is one of the Yams best features. Fred uses the BJ inlet
softener but although I’ve tried them I can’t say that I’ve noticed any difference to the performance. Fred
has used some longer Betor gas shocks at the back while I used shorter Showa units on the angled
shock positions like the Majesty set up and here I can notice a big improvement. Now if you are using
angled shocks you will need the very neat, and cheap Majesty chain guard to prevent fouling.

Shorter Showa rear units on the angled mounts with the neat Majesty
Chainguard on my No1 Yam

Early mods to the exhaust , front brace and 1 piece tank & seat unit

The complete remodel

Now for those that like to use that “clutch” thing (and of course I don’t) Fred has gone for a longer arm
and offset the fulcrum point for that softer pull. If you are going to use that clutch thingey then this is the
way to go along with a Moose or Works Connection needle roller bearing clutch lever. Do NOT be
tempted to remove clutch springs as some of the “Shade Trees” out there are doing….. it will eventually
warp the plates…… but of course it’s your motor! Fred is still using the 77 bash plate but I think the flat
BJ one might be better for a guaranteed cable pull ?

Some easy to vizulise changes on the clutch system

The original motor has been “breathed” on by Bob Ginder and now sports a 290 pot, electronic ignition
and a del orto which I look forward to testing (the other one was getting a bit clanky!) A 77 flywheel cover
narrows the engine and Fred has also machined the clutch housing on the other side to slim things
down there and also redesigned the brake pedal.

Not sure what the baby weighs in at but the original was around 209 lbs so with pieces of the frame
missing, the lightweight yokes, stem and exhaust my guess would be about 190 ???

So there it is, a lot of work and a lot of fun to get that “edge”…… but that’s Trials!

Better speak to Fred as to what it cost….. my lips are sealed.


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  • 11/9/2009 6:20 PM Fred Martinson wrote:
    For people information, I had bought
    the bike as a basket case in about 1999
    or so, so been tinkering with it for about 8 years, not much change the last couple of years.
    Bought a cub this past January, and now the modification cycle starts anew,
    modified footpegs, Dellorto carb, new
    yokes, modified frame, got to get the brake pedal on the right side.

    Reply to this

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