Paul's Yamaha 3MA track bike

[Paul]

hi edd
i have a 0.6 in the TZ and it too big
honestly itll suck too much at 10000rpm, meaning your mains need to go lower and not good.

[Paul]

She did her first track day yesterday and handled faultlessly. Tyres were the only let down. Oh and the crank.
It gave in and the 3MA gods were smiling on me as it gave in gracefully and did not trash the top end.
Head is wrong and needed a lot of advance but she ran perfect. New heads on the way and crank parts ordered.

[stevewr250]

Hi Paul glad you had a good weekend albeit an expensive one nice to see you fried you rear tyre and looking at the track on cranks post it's a wonder you didn't fry your tz cluch to

[Paul]

Ja it is a tiny little track but you do get speed and training.
3MA crank parts are not wildly expensive like the 3MA for some reason.
That crank is 24 years old!!!!

[Edd]

Hi Paul;

The bike looks very nice, glad she handles well will be looking forward to red star already put in some leave . I am waiting for new power jets decided to go two sizes bigger and bought 30's. Will stick those in and see what happens.

Edd

[Jakes]

Why do you think the crank failed? Big end?

[yanw]

"Hey my bru hit a luck". When the big end went on my 250LC it tore a web off the crank and the bearing left (eventually) via the exhaust port.

[Need4speed]

Hi Paul
Were looking at your update

Spoke to George. Asked him to find me another TZ and maybe one for you. He laughed. Says you don't see them anymore. They get snapped up too quick.

I just completed this web page today http://cjrenovering.dk/produkter/83-motorcykler-rr-renoverede/ and facebook here https://www.facebook.com/Cjrenovering
He has a lot of spareparts too... So far only 10% off the Honda racing parts are uploaded, Yamaha will follow.

[Paul]

Hey N4S. Will have a look. At the farm now with crap signal. Well done.
Jakes, crank was 24 years old! The engine has a full tune and pipes by Coker. It pulls hard. TZ style. So expected in a way.
Yan, ja, I'm lucky. I did 2 races knowing it was F@&$@&d

[Crank]

Have you stripped it yet? What does the crank look like?

[Paul]

Hopefully I get a gap tomorrow. Never stripped cases on a 3ma so have to take it slow.

[Paul]

didnt really take it slow
i tore into it like a baboon in a banana crate
i needed to know if the crank was toast like it sounded
suspicions confirmed, lucky it held out, centre bearings were wobbly
also the balancing shaft roller bearings were stiff and "grindy", more grindy in the way they made a tight noise, if you know what i mean
parts came for the crank yesterday, sent it off to "eddies crank rebuilds", thanks eddie
waiting for the rest of the parts
i must say though, been inspecting cokers work and its very clean

[Paul]

Spares are slowly rolling in from Japan on back order. Edd should have the big ends i posted yesterday on Monday. So hopefully I'll get the crank when I see him at red star en of the month.
I have thought of little else but riding this beautiful machine around Idube, it was beautiful.
So I looked at the top casing this morning. It was so grubby. I took to it with a dremmel, and a screw driver. Sand and stones were bonded to the casing in that horrible well in front of the sprocket.
Then scotch scrub, back on the dremmel then degreaser then polish, degrease, scotch scrub and finally.... Don't tell the missus.... Dish washer.
I am happy and am stopping at this point.

[Paul]

right
edd has nearly finished the crank on this bike, final balance up to follow
i have all the bits waiting except the roller balance shaft bearing
this bike has to have a lot of advance, coker said he originally couldnt get the ideal dome out of the heads as 3ma have a deep dome as it is
so he has welded up and started again, he is not charging for this work but i can imagine itll cost big to make a spare

[eyrey1]

the combustion chamber looks allot like the aprilia ones i just had done
sort of tz shape everyone i ask'd or checked with said it was the optimum shape