Yamaha Fun

[ShedBoy]

Taking a break from building engines to start and finish a project which has been in the making for 10 years now. I started with a bare frame the other day and started making bits I have been collecting for years to fit. I will let the pics tell the story but feel free to ask any questions.


RD400 rear wheel

The lump which will get a rebuild

XS250 tank

Redwing shocks installed

Position for new seat will require some mods to the rear frame section

Rear frame bit removal for shortening

Some drain hole I think after fixing that rust.

Shortened frame ready for welding

Trying to keep the original look.

Headlight from from a RZ125.
While rummaging around up on the mezzanine I found my next motor I am going to build. It will be some re-engineering.
Thanks for looking in if you are interested.

Brock

 

[windy]

Enjoyed your thread.
As just an armchair bike enthusiast now I still enjoy anything to do with them.
My passions are old classics and absolute speed record motorcycles powered by any type of power unit.
Would love to see the action by Sam Wheeler,Bub, Ack Ack and hopefully the UK contenders at Bonny in the future.

Paul

 

[enfieldbullet]

nice bike, and nice workshop too.

what are you doing with it exactly?

 

[jwcnc1911]

Oooh! That is going to be sweet when it's finished! I'd like to twist her ears!

 

[ShedBoy]

what are you doing with it exactly?

I am building a street version of a Yamaha Dirt tracker, if you google street tracker you will see what I am going for.
The frame is fairly well sorted apart from a few mounts to attach. So far it has 36mm forks from a XS750, RD400 rear wheel to replace the ballon tyre mag which it comes with originally, fuel tank from XS250 and aftermarket seat unit.
The engine has quite an extensive list of things to be done to it;
Crankshaft rephased 3 splines around to seperate the big ends
83°, camshaft rephased 41.5° to suit,%th gear overdrive set to lower the revs while cruising, permanent magnet alternator setup to replace the original troublesome alternator, hydraulic clutch, going to try and put electronic fuel injection using hopefully the throttle bodies from a late model Triumph as they look like the original carbs and the big if item will be maybe a lower ratio set of primary gears which I will need to make or get made because they stopped making them back in the 80's.
I think that is everything. There will also be all the standard boring little bits like wiring, brakes etc. This bike started as a frame in a corner of the shed which I kept moving around and an engine from another bike I had some time ago.
Anyone else got one of these bikes?

Brock

 

[ShedBoy]

Would love to see the action by Sam Wheeler,Bub, Ack Ack and hopefully the UK contenders at Bonny in the future.

Paul

I am planning on towing at trailer with the cruiser in the background to Speedweek early next year. It is the Australian version of Bonneville. Just got convince the commissioner of war and finance that it is a good idea, 2800km with only 450km of gravel roads. Should be no problem she is an adventurous type.

Brock

 

[windy]

Pity there's nothing like that in the UK we have a few 2 mile runways but you always having a constant battle over noise.

Was at Elvington watching some bike speed attempts and shakedown runs a couple of weeks ago fastest 239mph

A gas turbine thrust powered streamliner doing testing runs before going to Bonny next year
http://www.jetreaction.net/jet-bike

Brings back memories of my 1974 exploits having watched the Burt Munro film you never know still got some frame tubing in the workshop.

Was allowed to test run the model flash steam hydroplane they had the noise meter on it oops.

Paul

 

[jwcnc1911]

Paul,

That jetreaction website is nuckin futz. Since we've been talking I've paid attention to this kind of thing now. Did you drive or pilot (or what ever term would be applicable) one of those?

I guess I'll never break any land speed records... I don't have the sack to drive one of those!

 

[DPowell]

So, what does rephasing the crank do for you on the XS? They were known to vibrate a bit. Does it help with that?

Doug

 

[ShedBoy]

So, what does rephasing the crank do for you on the XS? They were known to vibrate a bit. Does it help with that?

Doug

This thread on another forum explains it better than me, post #12 has some good animations
http://www.xs650.com/forum/showthread.php?t=9211

Most parallel twin motorcycles these days are built with the throws set apart at 90°. Steam engines require it to be self starting.

As for the viabration it apparently does stop the middle area becoming numb and they sound like a totally different bike.
https://www.youtube.com/watch?v=tVpZ7hMXCj0

Brock

 

[Spoonman]

Gunna be a cool ride mate, can't wait to see it finished.

Anyone else got one of these bikes?

Sorta, I have an SR400 that I built up to be a Bobber/Bar hopper.

 

[ShedBoy]

Nice bike Spoonman.
What swingarm you have in that? I have a friend with a 600 looking for an ali arm. I love singles, got a IT465 twosmoker laying around which I would love to put on the road. Too many projects not enough time.

Brock

 

[Spoonman]

Cheers mate, awesome fun to hoon around on. Love the old smokers as well, Play toy I had years ago was a YZ490 evil evil bike !!!

Swingarm is a Motolanna http://www.motolanna.com/ourshop/prod_448876-Swingarm-Aluminum-Alloy-SuperTuff.html

 

[enfieldbullet]

I am building a street version of a Yamaha Dirt tracker, if you google street tracker you will see what I am going for.

we have a similar project over here at the shop, a boardtracker.

thought you would like to see it:

 

[Swifty]

With the mention of street versions of dirt bikes, it brought back memories when I did some road racing In the 70's. there was one friend that road raced his Yamaha dirt bike. Fitted road tyres, changed the sprocket ratio's and it went like a rocket.

Paul.

 

[rcfreak177]

got a IT465 twosmoker laying around which I would love to put on the road. Too many projects not enough time.

Brock

"Oh Yeah"

The good old Yamaha IT465, They were a weapon.

Did you know the WR450 that came out in the early 90's was the same engine. (old stock)
still a very sought after bike.

I once transplanted an IT465 engine into a 1991 YZ125 frame. This thing was insane I hurt myself several times on it.

Had a look at Youtube in regards to re phasing the cylinders on the bike you have, they sound unreal. Just might have to drop over for a listen and a chat when you get it started.

Baz. Thm:

 

[ShedBoy]

we have a similar project over here at the shop, a boardtracker.

thought you would like to see it:

Lovely little bike. I was driving around yesterday and seen a chap with a beautiful little cb125 cafe racer, had to follow him to have a better look.

Been trying to get more done but have got a farm hay roll feeder to fix then a boat trailer to put a new backbone in, then some brake rotors to drill and the shed will be all mine again. Should be finished today. It never ends.

Brock

 

[ShedBoy]

What a busy week I had. First up a hay roll carrier needed the top half replaced


Followed by a sick boat trailer which needed the back bone replaced

Then some blank hubs to be drilled for a muscle car which required some parts to be machine before I could actually drill but it will come in handy for other jobs.


Then I got some time to do some more to the Yammy

First the steering stop needed some repairs

That will help the turning circle no end.
Then a guard for registering the bike to keep it legal looking. The guard looked a bit tacky after shortening the frame so it required some surgery.

Looks messy behind the shocky


They have a wired edge which I needed to keep so I remove some and pushed the original edge up to give the back a cleaner look.


One side done.
Also got some header pipes for the exhaust which I forgot to take a photo of. Back to work tomorrow.

hanks for looking in.
Brock

 

[Spoonman]

She'll look sweet mate, had my "butchered" rear fender off today to take to work to sandblast the chrome off it (was carbon viynl wrapped) so I can give my new "lace" paint job was gunna throw up some pics but the fooker pretzel'd....

Time to hand fab a new stainless rear fender (and get it painted) before the weekend as I have a 500km ride to go on............. GRRRRRRRRRRR

 

[ShedBoy]

Need to give an update on the bike. Lots of little jobs done.


Exhaust are on and there is some rear pegs mounts on there too.

Tank front mounts had to be moved.


Rear tank mount needed to be fabricated from scratch.



Getting them coils to fit under the tank required some gentle violence to the inside of the tank to make room but is neat when on.
I will try to give more updates but other work keeps dropping in, still have to leave for evil work. To top things off I ordered a hotrod kit the other week and that will show up in a month so I need to get this off to the powder coaters and plating places, rebuild an engine etc etc etc. It never ends

Thanks for looking in.

Brock