Tri-z runs when kill switch is off

[sp1k3tou]

I'm having a problem with my tri-z. I took it for a quick spin down the street in the snow and when I came back it started to rev up and when I hit the kill switch it stayed running. So I pulled the spark plug wire thinking my switch was bad and it kept running until I pressed the throttle and it died. Now it will start up but rev high again. This is a rebuilt motor with stock spec's.

So I guess what i'm asking is... what causes this problem?

[dcreel]

Did you pull your spark plug wire and boot completely off of the spark plug, and it kept running? I wonder if you have a short somewhere, or a couple of wires crossed. Does the motor run in the run position? If it isn't electrical sounds like an air leak.

[harryredtrike]

cool its a diesel

[sp1k3tou]

yeah the wire was completely off. The bike runs with the switch on.

[dcreel]

Maybe its a bad ground.

[eyecekold1]

I had the same thing happen on my 250r and the kill switch wires had come loose some how. Only thing I can think is maybe they are not plugged in or maybe plugged backwards?
Its weird that the bike would run with the spark taken away. I know that 2 strokes rev really high when they are running out of gas or are jetted way lean.
Keep us posted I'm sure someone will help figure it out.

[sp1k3tou]

I went out side and now it will kick and only run with the choke all the way up and is reving high. Once you go to give it some gas it dies. It's to cold in my garage and I don't feel like waiting for the heat to warm it up. Dam I hate winter.

[Erics350x]

That would be the "death rev". STOP RUNNING IT! Its running very lean and will ruin the topend if you dont fix it. Most likely on a Z it the fuel pump going out. I'd clen the carb out real good and anything else fuel related first though

[RacerRichie]

Sounds like its running lean.....

[Erics350x]

For the Newbs, if that ever happens to you just hold it wide open and it will kill it.

[4cfed]

' ahh yes the death rev' start with the basics, clean the carb out,... and make sure the tri z pump is working, if not replace it or switch to a tri zinger tank.

did the temps drop drasticly since the last time you rode it?? if so thats why, cold air is more dence which makes them run lean, if thats the case you need to rejet it

[sp1k3tou]

Ok so it must be the fuel pump then since I rebuilt the carb in the summer and it was fine then. Thanks for the info. Can the stock pump be rebuilt?

I found a seal kit on ebay 38W-W1391-01. Is that what is needed to rebuild the stock pump?

[clutchcargo]

It's also possible that you have a bad crank seal, probably on the flywheel side and it's sucking air. I've actually had this happen. Keep it in mind if the fuel pump doesn't fix it.

[sp1k3tou]

I rebuilt the fuel pump and I still have the problem. I'm pretty sure the carb is causing the motor not to get enough fuel. The weird thing is I just rebuilt it last year but I think the kit came from ebay. I'm going to try and clean the carb out and if that doesn't work I will but a carb kit from the yamaha dealer.

[sp1k3tou]

A little update. I put new gas in the bike and it started to run better. Then when I went to start it a couple of days later she doesn't want to run now. I tested the coil and the connections were all rusty so I bought a new one along with a new plug which didn't fix my problem. Next I tested the stator and kill switch which look good. It must be time for a new CDI.

[MTS]

Give that carb a good clean, a half plugged jet is all it takes, if not, a leak down test needs to be done, it sounds like its lean, what color is the spark plug after running?...this is of course if it isn't already fried.

[sp1k3tou]

I pulled the carb apart and it is clean which I knew it was since I just rebuilt it. Next I replaced the CDI with a known good one and I still get the same spark but it doesn't want to run. The piston and cylinder were replaced when I rebuilt the carb. The weird thing is it fires one time and then it does not even try to fire again. Next I tried to pour a little gas in the cylinder and try to kick it but she wont even try to fire.

[sp1k3tou]

The cylinder is stock bore and should be stock compression. I just did a compression test and it has 180psi. The bike has been ran about 3 time up and down the street since the rebuild so I'm not sure if the rings are fully seated.

[honda250sx]

Christian have you checked the flywheel key? Forgive me if you have. I'm checking this from my phone.

[sp1k3tou]

If you talking about the key on the rotor its good. I tried to look for the timing marks but don't see them on the rotor.

[sp1k3tou]

I went outside again to see if I can figure out why it won't run and kicked it about 20 times. It fired two times. The spark looks great and I even installed a new plug. I'm going to pull the carb apart and check it but I just replaced the main jet before that happened and it looked clean in there.

[sp1k3tou]

I have been screwing around with it a little and now it sounds like the timing is off. It kinda sound like it farts at the end of the stroke. So I think I have a timing problem and now I need to find a flywheel puller that will work since the one I bought off of ebay a couple of years ago sucks.

[NINJA]

It sounds like you have it flooded now.

[sp1k3tou]

So I got the flywheel off and the bearing seal has a tear on the outer seal where the spring goes around. Once I removed the seal a lot of gas poured out. So I'm pretty sure I need to replace the tranny fluid? Along with the gasket.

[NINJA]

If the flywheel seal was leaking, you shouldn't have any gas in your transmission. The crankcase is seperated and sealed from the tranny. If the clutch side seal is leaking, then you could possibly end up with gas in the tranny.

After looking at that picture of your seal, was that seal installed backwards!? The side that has that little spring should be facing in towards the crank.

[theiizz08]

You said that you rebuilt the carb in the summer? its winter the jetting is not going to be the same it will run like Atrailprotrailpro In the cold much denser air

[honda250sx]

Glad your onto something Christian. Stop in and see me we'll get you fixed up on parts if you need something

[rickybudz]

Just think, I don't even have a kill switch. The bike came like that from previous owner. I have been meaning to get one. I'm just used to turning the key off now! I am used to it like this, but not recommended. It can be dangerous if needing turn off bike in a pinch!

[sp1k3tou]

I got the parts in today so before I installed the new seal the bike was tipped on it's side and a lot of gas came out of the crank case. I then wiped the bearing and put oil on it. Next I found a piece of PVC pipe to use as my seal installer and pounded it in. The bike started after 3 kicks and sounds happy again. It's a little to cold in the garage so I will finish putting it together tomorrow and see how she drives.

Thanks for the help everyone.