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goudrons

Ty175 Rattle, All Out Of Ideas!

21 posts in this topic

My TY175 rattles, it rattled before and it rattles now!

It rattled a bit when I got it, after a few outings it got worse, so it all came apart.

It was on it's last bore, so:

Barrel was relined (by reputable person) and machined to fit a new Wiseco Piston.

Crank had a new Conrod with new big and little end bearings. New piston pin.

New Main bearings and seals

All fitted together with care and new gaskets, twice!

All the parts came from a reputable company, so I presume they're good quailty, tried and tested.

Still the fecker rattles!!

What's going on??

Everything's been checked and checked again (at great cost), I'm out of ideas!

It shouldn't rattle, there's nothing standing out, Piston and bore clearance, big and little end is all new and looks fine.

Help!

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Hi I have had many ty 175 and 250's over the years ,I did the same with a whitehawk many years ago and still it rattled !! but since then every ty i have owned sounded the same performed well sounded like a bag of nails, just live with it if it performs well .

Regards Scorpa250

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It could be the slow running mixture or the ignition timing

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Well, I've ran it up until it got warm and pulled the top end down again, it's not had more than 10 minutes running since the piston and barrel went on.

Looks like the liners ovaled!

Front and back of the piston is marked up with tiny scores and the bore is marked up front and back.

F**k it!

My reputable man, may not be so reputable after all.

Things are now making sense, it had to go back once already as the liner didn't quite fit the crankcase mouth, seemed to catch on the corners, I guess I know why now!!

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Gday, how well did you clean it before assembly? Did you chamfer the ports? Clean airfilter, inlet tract and crankcase? What was the piston/bore clearance set to? You will get some marks even after 10 minutes. Maybe a picture will help to see. Its highly unlikely that you can oval a bore in that short a time. On the point of the engine noise, keep in mind that the TY is air cooled and will make more noise than a water cooled engine as there are no water jackets around the internals to insulate the sound. You should hear my PE250!

Cheers,

Stork

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I'll see if I can upload a few pics later.

It wasn't the normal fin rattle, but a metallic rasp/knock/rattle.

Apparently the liner can oval once fitted in the barrel (that's what I was told when it didn't fit the case mouth), as there's more pressure in certain parts than others, like the ports, so it can spread. Looks like when it was machined out to fit the piston, it wasn't checked properly.

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they're all like that, show me one that isn't!

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they're all like that, show me one that isn't!

No, I've had enough bikes over the last 34 years to know that it isn't right. I've had TY's before and none hammered like this.

Some pics, not great, but you can make out the scores on the piston, the top edge is also knarled.

http://i265.photobuc...gine/piston.jpg

You can make out the mark by the inlet port

http://i265.photobuc...07/engine/4.jpg

http://i265.photobuc...07/engine/3.jpg

That's after 10 mins at the most.

Edited by Goudrons

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Looks to me at first sight as the shop that has done the honing has forgotten to smooth out the edges of the ports, but the pic's arn't very sharp.

This would, -at last for me-, explain the heavy gutters you have in the piston skirt and the grounded area around the intake port.

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It does look like the piston is taking lumps off the ports, particularly the inlet, thought the exhaust looks a close second.

Those lumps it's knocked out have scored the piston.

Now here comes the big question, what the frick do I do with it now??

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It does look like the piston is taking lumps off the ports, particularly the inlet, thought the exhaust looks a close second.

Those lumps it's knocked out have scored the piston.

Now here comes the big question, what the frick do I do with it now??

get a proper engineer ( vehicle engine reconditioner ) (would be helpfull if you have the clearences for them to work from ) to measure it up to determin if it has been over bored and get them to wright down there findings ,also if the ports have not been relieved (chamfered edges) they did not know what they were doing and it had no chance of been reliable for long at all ,the steel broken parts could of caused other damage to other parts such as the new mains ,big end, little end so needs good inspection if the work is found to of been carried out wrong you need to go back with your findings and ask what they can do about putting it right ,but dont have them work on it again

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First the ports, as mention before, are not chamfered, second a Wiseco piston. I can tell you that a couple of specialist I know keep far away from them since they are very hard to properly fit and many time they are not realy TY piston, but sometime they are the only one avalable. I too would be p,,s of

Guy

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The chamfers ARE necessary! They aren't huge; simply a de-burring of the edge.otherwise they act as a shearing effect.

Also the slightest trace of debris (honing crap etc) left inside a 'dirty' port would cause that sort of damage in under 10 minutes.

Did you wash it out and 'air-gun' it or just take the reputable man's word for it?

Personally, I'd be taking a trip back for compensation.

I had a friend who took an open-topped petrol can and a lighter when he went to see a 'wide-boy' and demanded his money back.

It worked for him!!

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