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Post Info TOPIC: From bad to worse why wont this thing start?! Ttr250 open enduro


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From bad to worse why wont this thing start?! Ttr250 open enduro
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Hi everyone,

Im new to the forum job so bare with me and take a seat for this essay ha. 

So.. i recently bought a 1993 ttr 250 open enduro with very low miles. On my first ride out after buying it the starter packed up on the way home so i bumped it off and rode it home no problem. Once i got home and stripped it next day to see the problem it turned out the sprag had gone with smashed the starter gears, starter, engine casing etc etc. So after id finished crying and saved up a few quid i bought all the new genuine parts from totally ttrs to get it back together. I fitted all the parts no problem at all, came to start it after and it turns over sweet as a nut now but will not fire up!

 

So the hunt continues.... ive had it all in bits many times now to make sure ive done nothing stupid but i cant see what could be wrong. Ive got the key way in the flywheel, ive got a spark and a new plug, all wirings plugged in, theres fuel in the tank which runs out of the pipes to carb which ive cleaned out, theres compression if you put your finger over the plug hole when cranking. Ive had another battery on and even jump leads, and ive checked the cam chain timing marks which look all good. 

The only next thing i can think it could be is the cdi and having spent every penny on the thing and riding it once is fairly annoying to say the least. 

Any help from you would be grately appreciated as i love the look of this bike and wan to be back out after this lockdown if i can.  

 

Thanks in advance

Rob 



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if you have got a spark is it crisp & blue if so i cant see it would be the cdi when ive had problems like this i have sprayed brake cleaner down air cleaner tube be very carefull if it fires up you have got fuel problems BRAKE CLEANER IS FLAMMABLE NOT TOO MUCH YOUR DECISION v

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Aah yes i forgot to say, i did try spraying a bit of brake cleaner down the inlet and it still doesnt fire up on that. So i guess spark timing must be wrong from cdi



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is it turning over fast enough

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How can i tell if its fast enough? Seems ok mind even with jump leads on it 



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Does it fire at all or spit back - any sign of life? 

Spark plugs can be problematical from new (on rare occasions) so maybe try a different one just to be sure?

Is the petrol clean and fresh? And definitely petrol and not diesel? Don't ask disbelief

Bearing in mind the float bowl drain plug is rounded out, could you lean the TTR right over and check the carb floods? 

Brian

PS If all else fails, there is a very comprehensive check list, albeit generic, here.



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Yeah ive tried a couple of plugs, the petrols fresh. I know when i took the float bowl off it had fuel in. It doesnt pop back or anything. What are the symtoms of a cdi normally? Could it be something valve related

Ill take a look at the check list. Cheers 



-- Edited by Scarth28 on Sunday 31st of January 2021 07:43:05 PM

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Rob

It is sounding like the cdi, you can send it to me for testing. Make sure you mark it properly  as I have a few here and don't want to mix it up.

Don't think it is bent valves , as you would have no compression. 

Steve 



-- Edited by ttr steve on Sunday 31st of January 2021 09:20:54 PM

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I would be inclined to look at the coil first. A failing coil will struggle to produce a spark under compression.


Cheers, ff.



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Cheers steve, i will send it down even if its just to eliminate it. cheers



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Is the plug wet after spinning it over? If not I would still suspect fuel issues.
If the cdi had fried during jump lead shenanigans, why would that affect the spark timing? Surely it would just give up altogether? Is the stator and pickup sensor all bolted into the LH case correctly?

Not sure if you would get a spark if the pickup sensor was damaged or not connected, but generally I would say that if something stops working after you've done a job, look at the things you've done first before going off on a tangent.

 

https://ttr250.activeboard.com/t62021383/ignition-pickup-coil-or-sensor-replacement/

 



-- Edited by mossproof on Monday 1st of February 2021 08:27:43 PM

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I was testing cdi's on my own bike with Brian, the bad ones would turn over the bike but not start the bike.

I don't know all about cdi's, but that was the only way I could test them.



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My only thought is the air gap at the pick up coil.

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Still nowhere, but ive had the cdi tested on another bike and its fine. Is there any specialists out there that could look at it for me.? Tia

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The basics are

1. compression
2. air
3. fuel
4. spark
5. timing if 1-4 are all ok, what about valve timing
6. lack of compression due to valve clearance or decomp stuck or not adjusted correctly

Cheers Terry

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Can you upload a picture of the cams in TDC



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