Tri-z help needed in arizona

[Stephon_xr500]

Hello,

I figured I would throw this out to the 3wheelerworld.com community

I'm looking for some help with my 86 tri-z 250, I had it running this week but it died on me while test riding it down my street. Now it won't start, it still has good spark I changed the plug. It is getting fuel to the carb and to the jug. It sounds like it still has compression but I don't have a gauge to check it.

I have been having carb issues with the 38mm I was trying to use so I swapped back to a stock carb. It ran after that but only for about 10 mins then shut off.

I'm hoping to get it looked at and fixed in time to MX race it this season here in Arizona. I was close to getting it out to the track this Saturday but it looks like I'll be racing my 350x instead.

202985

[El Camexican]

Fuel to the jug? As in via the carb and into the cylinder, or the line from the bottom of the cylinder to the fuel pump? If the later there lies your problem. That line is for vacuum, not fuel, your pump would need a $20 rebuild if this is what is happening.

[Stephon_xr500]

I ment via the carb, the plug is wet. The best I can get is a backfire. I've had it running for a few month's, just terribly. I found that I lost my idol screw and had air leak, I fixed that.

[King Trikester]

A combination of a plugged fuel tank vent line and a petcock that wasn't quite in the right position simulated the same symptoms. Mine would run for ten mins ten crap out.

There also was a time that it wouldn't start and it seemed to be getting fuel, the plug was wet, I kicked it over and over and over but nothing, ended up leaving it for the night, it fired up first kick the next day and has been running perfect since.

[muthey]

I would also check the pipe and see if it is plugged or full of unused fuel, also check your reeds for a one or more broke or sticking.

[danbur55]

Know you said has good spark but pull plug cap and clip 1/2" off of plug wire and try. My lil zinger drove me crazy had spark when grounding to head but may or may not start till i clipped some off of plug wire and hasnt failed yet. Good luck

[jb2wheels]

Don't these have a vacuum fuel pump? I haven't dealt with one since my FL250 days and I can't remember what the failure symptoms are but this is what I thought of reading this thread.

[Stephon_xr500]

Thanks for the ideas guys, I'll be checking fuel delivery system early next week. I have had the trike for about 8 months but have only ran the motor for a total of about an hour. I went through the fuel pump and lines. I've eve changed the fuel tank.

[El Camexican]

Don't these have a vacuum fuel pump? I haven't dealt with one since my FL250 days and I can't remember what the failure symptoms are but this is what I thought of reading this thread.

Yes, and as far as I can tell the reasons for failure vary. Mine was leaking air and I've heard of other having fuel get into the vacuum line side of the pump. Don't quote me on this, but as best as I can recall the stock pump in good condition can put out up to 32, or 34 gallons per hour. Way more that that engine could ever burn. I believe some people have switched to the small rectangular pump found on some dirt bikes and snowmobiles. I think that one can put out 10 gallons per hour and that was enough to feed a 440cc sled engine, so in stock trim the Tri-Z needs a return line for all that extra fuel. The rebuilds are simple and cost $20 to $30 on eBay for genuine Mikuni parts. The only issue I know of when the pumps work well is that they can push float needles off the seats of non-stock cabs made to work with gravity systems. The fix is a larger return hole in the tee (the stocker is very small, but looks big because of the large hose) I don't know what the hype over top tanks is on Tri-Z's, but they seem to be coveted.

[Stephon_xr500]

Well after loading my 350x in the truck and getting all my gear ready for the race tomorrow, I was able to troubleshoot the tri-z a little bit more. I hooked up a gravity fed tank. Still no luck I was able to get it to backfire a few times but that was it. I had the intake tube off and was able to see fuel misting out of the carb.

[CRAZY70MAN]

38mm is a pretty big step up from stock 32? Any mods?? Has it ever ran with that carb? Put stocker back on and try it....

[Stephon_xr500]

I didn't have a stock carb when I fist got the trike, so I was using the larger carb off an 82 yz250 that I had available to me. I swapped to the stock carb and that's when I had the issue with it shutting off. The trike ran the best it has since I've owned it on the stock carb right before it died.

[MTS]

Check your woodruff key on the mag , sounds as if it sheared, its firing but not at the right time.