Gasket tickness

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Guy53
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Re: Gasket tickness

Postby Guy53 » Fri Sep 23, 2011 8:42 am

I found an aluminiun sheet that is mild ( pliable ) and is .006 in thick so I will make a couple of copy and make different test. FM 350 aren't you afraid when using silicone for a cylinder/head sealer that heat won't transfer from the head down?

And finaly seem's nobody know's the original tickness of the base gasket.. :cry:

Guy



David Lahey
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Re: Gasket tickness

Postby David Lahey » Fri Sep 23, 2011 9:33 am

Guy I have run out of new TY250 base gaskets but did find a new TY175 base gasket which I measured last night at 0.6mm thick


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FM350
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Re: Gasket tickness

Postby FM350 » Sat Sep 24, 2011 9:00 am

Guy53 wrote:I found an aluminiun sheet that is mild ( pliable ) and is .006 in thick so I will make a couple of copy and make different test. FM 350 aren't you afraid when using silicone for a cylinder/head sealer that heat won't transfer from the head down?

And finaly seem's nobody know's the original tickness of the base gasket.. :cry:

Guy



Ditching the head gasket and using silicone is something that is tried and tested on the TY250 Mono, and as long as you let it set overnight there will not be any problems at all. Using gaskets on bikes with excessively wide squish clearances, is something that makes the clearance even wider and is not that great an idea.



tat ty
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Re: Gasket tickness

Postby tat ty » Sat Sep 24, 2011 9:05 am

I located a Genuine TY250 Gasket Set.

The Base Gasket is 0.6mm

Alastair Farquhar



Guy53
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Re: Gasket tickness

Postby Guy53 » Mon Sep 26, 2011 9:54 am

Thank's Tat Ty, it will help me get the right port hight on the next motor ( and I will also setup the current one ) The 434 motor I curently use was quite unpleasant to ride at the last comp we ad, so I tried to adjust it, it seem's to be lean at low speed and was not picking up at all, I installed a 0.020in head gasket witch helped a bit check the carb to see if if everything was clean everything was ok raised the needle ( lowered the clip ) it was a little bit better and finaly receved my Mikuni carb ( ordinary round slide ) this carb was ordered for a project but I couldn'd resist trying it on the 434 heaven if I don't have the perfect jetting.I have to tell you it made a big difference in low end power, after an hour of practice I put back on the 13t front sprocket, practice another hour and decided I have to get another Mikuni for the project.

Guy



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Re: Gasket tickness

Postby FM350 » Wed Sep 28, 2011 5:43 pm

Couple of very simple things which will improve old TY250s, is to properly clean out the exhaust system, and remove the flywheel weight.



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Re: Gasket tickness

Postby David Lahey » Wed Sep 28, 2011 6:53 pm

I took the weight band off and rode for a year on an otherwise standard TY250B in very good mechanical condition. While it had good pickup, I found the motor was too easy to stall. I then put the weight band back on and progressively machined away the band until I was happy with the way it was to ride. I ended up removing about 1/3 of the weight band.


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Guy53
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Re: Gasket tickness

Postby Guy53 » Wed Sep 28, 2011 7:29 pm

I David

The flywheel on a B model is heavier than the A model here in Canada and the porting is allso different, I removed the weight on my A model before I took it out of the basement so I can't comment on the difference with or without, but stalling was never a problem for me, yes it stall sometime but I know it's rider's error. I should be out for a friendly comp this weekend ( the weather won't cooperate ) so it will be muddy conditions, I will see if my feeling for the improvement is wright.
How long do you normaly ( I know that it depens on the condition of the exhaust ) have to burn the pipe to clean it A couple of hours or 5 or 6 hours?

Guy



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Re: Gasket tickness

Postby David Lahey » Wed Sep 28, 2011 7:56 pm

Guy I've sent you a PM
The deposits can be burned out or removed cold (chemically). Some bike shops can do the chemical (solvent) method, which is the only option for aluminium exhausts.
Flywheel weight is a very personal thing so there will never be agreement about what is the best. I feel that the better a motor runs, the more flywheel weight can be run without making it feel slow. I have a D model TY250 motor in a Godden Majesty that goes like a train even with the 2/3 size weight band on it - a very sweet motor. The biggest improvement I have found (after getting the motor in perfect mechanical condition, cleaning the main section of the exhaust and getting the jetting perfect) was to fit a WES rear muffler instead of the standard muffler.


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Re: Gasket tickness

Postby FM350 » Thu Sep 29, 2011 5:51 am

The old TY250 twinshock motor is a little gutless, and the main reason for removing the flywheel weight is to give them a bit more get up and go, which makes the bikes easier to ride in modern type sections, which are often a lot tighter than those common in the 1970s. Better still though is to fit better intake and exhaust systems, do some alterations to the porting and squish clearance, which will greatly improve running, to the extent you can then fit a heavier flywheel weight.




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