won't start when cold

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dandywarhol
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Re: won't start when cold

Post by dandywarhol » Fri May 01, 2015 11:11 pm

I just got a Viton seal kit from member maelstrom in Thailand. Great service, here in a week. ☺
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

Markula
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Re: won't start when cold

Post by Markula » Wed Jun 24, 2015 10:18 am

Final update - She's fixed and running like a trooper! :P
After stripping carbs, ultrasonically cleaning them, rebuilding with a new overhaul kit the problem was still there!

So next I whipped of the valve cover and checked clearances... All of the inlet valves were tightened up with little or no clearance. So 6 new shims later and a few nights in the garage she was back together and fired up first press of the button.

Very happy to be back out scratching around the countryside again.

Thanks for all the pointers and support.

Mark

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dandywarhol
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Re: won't start when cold

Post by dandywarhol » Wed Jun 24, 2015 10:54 am

Good to hear - might see you at The Leadburn Inn on the first Thursday of the month
1996 TRX 850, blue, Ohlins 46HRCLS, Race Tech Gold Valves, 0.90 springs, Venom pipes, R6 brakes............
1974 Yamaha RD250A, Candy Blue
1998 Yamaha SZR660, blue of course
1967 Yamaha TD1C 250, Blue and white

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Con Rod
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Re: won't start when cold

Post by Con Rod » Wed Jun 24, 2015 1:20 pm

Markula wrote:Final update - She's fixed and running like a trooper! :P
After stripping carbs, ultrasonically cleaning them, rebuilding with a new overhaul kit the problem was still there!

So next I whipped of the valve cover and checked clearances... All of the inlet valves were tightened up with little or no clearance. So 6 new shims later and a few nights in the garage she was back together and fired up first press of the button.

Very happy to be back out scratching around the countryside again.

Thanks for all the pointers and support.

Mark

do you know what size shims you used on the inlets? Be curious to know if there were 170/175 or close to 150
Paul

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M.V.
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Re: won't start when cold

Post by M.V. » Thu Jun 25, 2015 2:51 am

Markula wrote:Final update - She's fixed and running like a trooper! :P
After stripping carbs, ultrasonically cleaning them, rebuilding with a new overhaul kit the problem was still there!

So next I whipped of the valve cover and checked clearances... All of the inlet valves were tightened up with little or no clearance. So 6 new shims later and a few nights in the garage she was back together and fired up first press of the button.

Very happy to be back out scratching around the countryside again.

Thanks for all the pointers and support.

Mark
Glad you got it sorted, good news.

Markula
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Re: won't start when cold

Post by Markula » Thu Jun 25, 2015 6:32 pm

Thanks for the support guys. The shims that I had to put in ranged from 145 up to 160.

I will try and make it through to the Leadburn Inn next week. You can recognise my Trx as it has a speedblock design on the tank but a black fairing at the moment. I am slowly bringing it back to standard from it once being street fightered in its past life by a previous owner.

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Con Rod
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Re: won't start when cold

Post by Con Rod » Fri Jun 26, 2015 12:51 am

Markula wrote:Thanks for the support guys. The shims that I had to put in ranged from 145 up to 160.

I will try and make it through to the Leadburn Inn next week. You can recognise my Trx as it has a speedblock design on the tank but a black fairing at the moment. I am slowly bringing it back to standard from it once being street fightered in its past life by a previous owner.
I would keep an eye on that. Keep at record of the adjustments you made so you can refer to them in the next check. The original shims would have been between 175 and 190, maybe 192 so your clearances have closed up a reasonable amount. You can keep using smaller shims so not the end of the world but it is likely that in the long term you will need to replace the inlet valves.

Is it a 96 bike?
Paul

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Re: won't start when cold

Post by Markula » Fri Jun 26, 2015 10:28 am

Yup it's a 96 bike. So the one with the stretchy valves!

Cheers
Mark

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dicky
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Re: won't start when cold

Post by dicky » Fri Jun 26, 2015 10:54 am

Markula wrote:Yup it's a 96 bike. So the one with the stretchy valves!

Cheers
Mark
Wrong!
There is nothing wrong with the valves.
They have soft valve seats.
They wear and in extreme cases can leave the valves partly open which lead to more problems as it then burns the rest of the seat and valve assembly.
dicky
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cobbadiggabuddyblooo
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Re: won't start when cold

Post by cobbadiggabuddyblooo » Fri Jun 26, 2015 6:54 pm

I think you'll find it's the valves Dicky.
Thats why the part number on the xtz750-and pre 97 TDM/TRX's inlet valves are listed as a revised part number and now are the same number as the later TRX/tdm's models
laughter is the best medicine

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Con Rod
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Re: won't start when cold

Post by Con Rod » Sat Jun 27, 2015 12:53 am

cobbadiggabuddyblooo wrote:I think you'll find it's the valves Dicky.
Thats why the part number on the xtz750-and pre 97 TDM/TRX's inlet valves are listed as a revised part number and now are the same number as the later TRX/tdm's models
yes, definitely, the valve faces wear, see images in the thread

http://www.trx850.com/phpBB_forum/viewt ... &start=180
Paul

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