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The TTR250 FAQ web pages -> TTR250 -> Repairs and maintenance -> ttr 250 won't start
Post Info TOPIC: ttr 250 won't start
efiles123


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ttr 250 won't start
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So i'm still trying to fix my friend's ttr 250 after it sat for 2 years outside.  Before that the bike ran fine so I decided to tear down the carb to find it filthy.  After a thorough cleaning with solvent and compressed air, I replaced the float valvle assembly before re-assembling the carb.  I charged up the battery and gave her a try and after several attempts the bike would not start.  I checked spark and fuel, both fine.  Air filter was just cleaned.  Poured a little fuel down the spark plug hole which still didn't work.  I'm stumped at this point.  The only thing I didn't disassemble in the carb was the diaphragm at the bottom of float(just realized this may have been an important part to check).  Compression test showed 60 lbs and 90 lbs after putting some oil down the spark plug hole.

What should I check next?



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TTRfan


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Have you got a spark?

If you open the drain valve at the bottom of the float bowl, is petrol flowing out OK?

If you haven't done so already, get rid of the old petrol, swill out the tank and put in fresh fuel.

If it has been standing for a couple of years then the piston rings may have stuck into the piston and may benefit from a soak of oil (as you have done) to help free them up.

It may be worth hooking on an extra battery to make sure it is spinning over fast enough to get everything working!

If all else fails, and you definitely have spark and fuel going through, a squirt of ether into the airbox might encourage some life wink

Let us know how you get on.

Brian

PS a much more comprehensive guide is here



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burton500


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Re: Compression test

My manual says 145 psi min when warm.  Allowing for your engine being cold, your figures still seem low?

Lee



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efiles123


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Its got spark and fresh fuel that flow out the carb when I turn the drain screw.  The battery seems to turn everything over according to the sound it makes.  I was already thinking about putting starting fluid into airbox- I think I'll pick up a can.



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efiles123


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burton500 wrote:

Re: Compression test

My manual says 145 psi min when warm.  Allowing for your engine being cold, your figures still seem low?

Lee

 I read that too and it is definately low which doesn't surprise me after finding dirt in the passage beyond the air filter.  However, the bike ran fine before it sat for 2 years.



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Haggis Hunter


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I had a problem a few years ago with a bike that would not start after sitting for a few years. Like yours it had a good spark and fuel was getting through but it refused to go. I found that the inlet valve was in the open position all that time and there was corrosion on the stem which would not allow the valve to close fully, lowering the compression enough to stop the thing starting. In those days of kick start only and the impatience of youth I took it to the drive of the local farm which was very steep and very long put it into 3rd gear and went for it. It turned over for about 5 seconds before bursting into life. I rode it around for a few miniutes and after that it started fine!

What reminded me of this was a neighbour asked me to look at a small generator that would not start after siting for some time. There was very little compression so I removed the rocker cover to find the exhaust valve not closing fully. A squirt of WD40 and a few taps with a hammer got the valve to shut and the engine started.

Any big hills near you??

 

Peter

 

 



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TTRfan


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Haggis Hunter wrote:

Any big hills near you??

 biggrinbiggrinbiggrinbiggrinbiggrin



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efiles123


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Finally got it started today.  I sprayed some carb tune-up cleaner in the exhaust port in order to soak the valves.  I tried jumpstarting the bike in 3rd and after that failed I used the start button and it fired right up.  I guess one of the valves must have been stuck and possibly the combination of the carb spray and jumpstarting got things moving again.  Hopefully this thread will eventually benefit someone else.



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TT-R250M


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It might sound wrong but I have used Deisel to unseize old engines that the bottom end bearings were seized. Some of them still going to this day s It is smelly stuff thought, so I wash it out with Kerosene, after leaving the Deisel soak & work it's magic s

Works a treat

 



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