Fuel + Spark = Non running trike?

[Derrick Adams]

We went riding the other night and took the 83 R out on it's second trip since the fresh rebuild. Ran great for an hour, then died while riding it. After about 5 minutes it started back up then rode it down the road about 1/4 mile and it died again. After a few minutes it started back up and ran fine. I figured the something it the electrical system was over heating because the head light bulb is out of who knows what and what wattage. Flipped the light on low and ran fine for about 2 miles (20 minutes) Died again and wouldn't start.

I changed the plug, it has spark. Blows my finger off the plug hole when I kick it over, so it has compression (haven't got a gauge on it yet) and checked the carb and it is getting fuel. I even poured alittle fuel down the plug hole just to be sure. It just won't run. Occasionally it will pop out the exhaust, but has yet to attempt to fire.

WTF? Any ideas?

Think I should get it warmed up and see if it will run? It's only been about 15 degrees out lately.

[Troll 2]

Sounds like its running out of fuel? Possibly the strainer in the petcock or float/needle-seat .......good luck

[Derrick Adams]

Nope... Checked those. No problems there. It's definately not a fuel issue. The spark seems to be pretty decent too. I don't get it.

[Quickonstep]

ok take the plug out, clean it off, kick it over a few times to evac anything that is in the combustion chamber, put the plug back in, kick it over a few more times and then pull the plug, see if there is any fuel on the plug.. if there is then it could be a reed issue.. if it isnt then its a f uel issue.. it sounds like a fuel/air leak issue.. hope this helps you some

Jesse

[Derrick Adams]

Pulled the Head. Cylinder is trashed. That sucks, 2 rides on the new top-end.

[BLAZERONE22]

Man that sucks, sounds like the issues my 82 R had then I got it. Manny had the complete motor rebuilt for like 800 bucks took it out and rode it and it just stopped, the he called me up and sold it to me cheap. I checked everything over, had fire, fuel and compression. after a compression check relized that was the problem and took the head off, It had a minor sieze up and needed another top end job. I figured the reason it happened was because Manny had mickey moused a K&N air filter into the airbox and it was'nt sealing right. And I don't think the paddle tires he had on there during breakin help matters any also.

[Derrick Adams]

The thing is, I can't figure out what would have caused it. It has 2 huge grooves in the front of the cylinder, inline with the exhaust port, just like before. How would that have happened? Could it have been lean? The plug looked great. I didn't see any issues with the rod that could have caused excess play in the piston.

I have a couple lines on some cylinders so, I'll try it again and if it blows next time i'll just have to do something drastic. At this point i'm leaning toward it being lean and causing the issue. It would make since that the exhaust side would get hot and damage first. I'm definately changing the carb this time around too, never seemed to rev out like it should. Guess that's an expensive lesson to learn.

[Quickonstep]

are the locator pins in the piston? take a look for them

Jesse

[Derrick Adams]

Well, they were in there when I installed it. Who knows now.

[Mick04]

Make sure that your crank seals are good. I have fried many a two strokes because of this. Have they ever been replaced by you?

[RideRed250R]

did u lose a ring? have a ring catch the exhaust or intake port?
adam
i hate storys like that i blew up my sold R once brand new top-end just had a ring catch the exhaust port
adam

[TimSr]

When its from running lean, the top of the piston, mostly on the exhaust side, will look like its been sandblasted away. Grooves in the cylinder arent normally a carburetion problem. What do the piston and rings look like? If a ring or rings are damaged, they may not have angled or rounded the ports correctly after the bore job. This is especially a common problem with bore jobs done by places who dont specialize in 2 stroke bikes and ATVs. Only Wiseco bores mine.

[Derrick Adams]

I haven't pulled the cylinder off yet, but the top of the piston looks like new in the center, with some black carbon all the way around the outside edge. I know the last time it had a broken ring and it had done the same thing at least once previous becasue they didn't bore the cylinder, just honed it and left the grooves in it. I'd bet any amount of money that it has a broken ring again. That's the only way I could imagine getting grooves dug into the cylinder like that (unless the skirt did it).

[googel35]

If you were to check the crank seals would you have to split the bottom part of the engine or would the the round covers on either side be the place to check to make sure the bearings or seals are good. I was told to take the cover off each side and make sure the crank doesn't move but I was uncertain what they ment by the cover. I've had the same problem that was described here but my rings would sieze up in the piston and it had that kind of sand blasted look. It also fouls the spark plugs really quickly. Took my 82 250r out today and put new gas and plugs in it after cleaning the carb and putting a gas filter on it. Had my buddy ride it around and after about 20 min. it stalled out and wouldnt start. I took the spark plug out and the base of it had a shiny copperish look too it and the inner part of the plug was all charred black. Is there another way to check to see if the seals are bad because I know it is running lean and I want to make sure that what is causing it to run lean is so I dont burn the motor up again.

[phil53]

do a leakdown test. a 2-stroke should hold 6 psi for 6 minutes. leak check w/ soap bubbles. you have to remove the exhaust & block it off. pressurize thru the intake boot with an aspirator bulb, low pressure pump. the bulb from the thing used to check blood pressure is what i use.
or remove the cylinder & fill the crankcase w/ oil and see if it leaks out