Author Topic: Waterproof points?!  (Read 1213 times)

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Offline zorroz

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Waterproof points?!
« on: August 01, 2010, 08:59:51 pm »
Just started pulling down my DT3. The motor still had good spark but wasn't running due to failed output shaft bearing. I tipped the motor on its side and found water in the magneto. Thought I had it all drained out so when I popped the cover off and I got covered in brown muck! Anyway to my surprise, the flywheel and points were crusty as, like it had been sitting on the ocean floor! The flywheel came off easy another surprise. I remember trying to take of Suzuki PE flywheels of with correct puller only to bend the crank end and find magnets all fallen off. This motor is a true testament to yammie reliability.  ;)

Looks like the water was just below the points:





« Last Edit: August 01, 2010, 09:03:40 pm by zorroz »

Offline jimson

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Re: Waterproof points?!
« Reply #1 on: August 01, 2010, 09:46:16 pm »
How will you clean that up. The Yammie I just bought was outside for the last 20years and the swingarm is rusted through but when I took the side cover off the flywheel it looks like new  :o jimson
Just a balless freak having a go

Offline frostype400

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Re: Waterproof points?!
« Reply #2 on: August 01, 2010, 10:39:19 pm »
Found similar looking brown gunk in my rd250 master cylinder was still working too.
1971 tm400 and PE's

Offline brent j

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Re: Waterproof points?!
« Reply #3 on: August 02, 2010, 10:56:13 am »
Rust in the ignition area seems to be a Yamaha speciality!
I pick up an SR500 motor a few years ago that was locked solid. It had a WEISCO 560 badge on the flywheel cover so decided to pull it down and have a look. It wasn’t 560cc and once the head was off I found the piston was quite free but the motor still didn’t turn over. I went to pull the ignition cover off to get a socket and bar on the crank but the cover wouldn’t budge. With some effort and care I removed a cover that was jammed solid with rust. It had locked the flywheel in place! Once freed up and fitted with a new crank seal the motor ran fine.
It turned out to be 522cc not “560” and had a high comp piston that measured to almost new spec. Those parts obviously found their way into my current race motor.
Thinking about it, fitting fast parts to my motor just removes another excuse for my lack of speed on the track ::)

Brent

PS I now run good gaskets and breather hoses on the ignitions of my on bikes!
« Last Edit: August 02, 2010, 01:03:37 pm by brent j »
The older I get, the faster I was

Offline Freakshow

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Re: Waterproof points?!
« Reply #4 on: August 02, 2010, 11:35:17 am »
I always now take the Ign side cover off after wevery race and just let it sit out llose.  I found no matter what you do water from washing gets inthe pipe, or it just get condensation in there and start to eat away at the bottom of the cover.

For the sake of removing 4 little allen bolts a few turns your always better off when its parked.    Infact this ran true after braodford, came home parked the bike then a week later went to put it away and about a litre came out, must have been from that cleaning staion down the hill i used before i put the bike back in the van,  Had i not bothered to undo the side that water would have been as high as yours in there.

Best to always leave it loose unless your riding, and if you do it always, youll remeber to check before you get to the start line, like checking the fuel taps on.
74 Yamaha YZ's - 75 Yamaha YZ's
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For sale -  PRE 75 Yamaha MX stuff, frame, motors and parts also some YAM DT1,2,A and Suzi TS bikes and stuff