yt 125j wont F-in Start!

**lilman420** · 11-14-2009, 05:40 PM

iv got a 1982 yamaha tri moto 125j. the carb is clean as a whistle and the spark is bright as day... this freeking thing is pissing me off bad... iv been told to check the timing.. problem is that i dont know how.. were are the timing marks? i know when its tdc but i cant figure out how to adjust it... someone please help me.. i traded my beretta for this pos and now im wishing i didnt... please help

**Vealmonkey** · 11-14-2009, 05:56 PM

OK, to make it run you need fuel, spark and air. Have you tried a little starting fluid in the cylinder and then pull starting? Just cause the carb is clean doesn't mean fuel is getting in the cylinder. Is the fuel valve open? Is your air filter clean. You must run with a clean airfilter. If you run with a dirty air filter it won't get enough air to fire. Also running without an air filter is bad since it will cause the trike to run lean and it will over rev. If it revs out and the kill swtich won't kill it, you will have to pull the plug wire off the plug! Have a rubber glove handy or you will get the cheap thrill of your life as you get zapped really good!!!!! But I would make sure you are getting fuel into your cylinder first.

**lilman420** · 11-14-2009, 05:59 PM

iv tried putting carb cleaner in the cylinder and it dosent even burp... do i need to use eather.. i thought carb cleaner would work

**MudBug** · 11-14-2009, 06:13 PM

do you have compression?

**lilman420** · 11-14-2009, 06:16 PM

yes
there is compression

**TrailerRider** · 11-14-2009, 06:35 PM

Well, I just went through the same dam thing with my brothers pos rmx 250. Had great compression, spark, fuel & air and still would not run (Not even try). Turns out the plug was fouled. Yes it would spark great when testing but under compression it did not produce a strong enough spark. Replaced and the sob started right up. Even if your timing is off with starter fluid you should still get a pop, fart or backfire etc from motor, even though it will not run. like stated before you have to have Fuel, Air, Spark & Compression. Tried without the air filter for a TEST and replace plug for good measure..

**85Tecate** · 11-14-2009, 06:58 PM

Originally Posted by TrailerRider

Well, I just went through the same dam thing with my brothers pos rmx 250. Had great compression, spark, fuel & air and still would not run (Not even try). Turns out the plug was fouled. Yes it would spark great when testing but under compression it did not produce a strong enough spark. Replaced and the sob started right up. Even if your timing is off with starter fluid you should still get a pop, fart or backfire etc from motor, even though it will not run. like stated before you have to have Fuel, Air, Spark & Compression. Tried without the air filter for a TEST and replace plug for good measure..

+1 start with the simple things. Chances are spraying carb cleaner, pouring fuel into the cylinder has wet fouled the plug. They will still fire out of the head, but not under compression.

Change the plug and retry. Also be SURE fuel is getting into the cylinder...

**daniel_250r** · 11-14-2009, 07:52 PM

get a new plug like stated and have a buddy pull you on a quad or something with the trike in gear sometimes that helps alot

**old-yellow** · 11-14-2009, 10:51 PM

There is no timing marks because the trimoto's have CDI with a magnetic pickup, the only thing that can change timing is if the flywheel key breaks and the flywheel spins on the crankshaft changing when the flywheel magnets spin past the magnetic pickup. Did you do a compression test or just look at the piston rings to see if there good?

**lilman420** · 11-15-2009, 01:01 PM

ok so i tested the carb to see if its pulling air.. it is. and i bought a new plug.. this pos still wont start... pure eather wont get it to fire.... whats wrong here

**inv3ctiv3** · 11-15-2009, 01:09 PM

My first 200x was like that, wouldn't start no matter what and it had everything (air, spark, fuel, compression).....A couple of friends and I pushed started it a few times and sure enough it ran afterwards.

**code200k** · 11-15-2009, 01:11 PM

Originally Posted by inv3ctiv3

My first 200x was like that, wouldn't start no matter what and it had everything (air, spark, fuel, compression).....A couple of friends and I pushed started it a few times and sure enough it ran afterwards.

same with my Z i must have kicked that thing over 100 times then we pop statred it and she ran did it a couple more times and now she runs ok..

**Vealmonkey** · 11-15-2009, 04:13 PM

If you put ether in it, then I would say it's not getting spark! I hoped you held your throttle open if you sprayed the ether through the air filter or carb or you didn't get any ether in the cylinder. If you tried putting ether in the spark plug hole, sometimes it dissipates before you get a chance to pull start. Try ether again in the airbox while holding the throttle lever open and try pulling again. Not to be mean, are you sure that the start button is in the "on" position? It happens.

**beets442** · 11-15-2009, 04:22 PM

Mouse nest in the exhaust pipe?

Beets

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yt 125j wont F-in Start!