Weedeater GTI 17T, I'm baffled. Please, please weigh in...I need help.

So I am not exactly new to small engines, and do plenty of car work but this trimmer is driving me crazy, I'm just trying to do my uncle a favor.

So this thing doesn't do anything when I first get it and has oil coming out of the cover seems. I take the whole thing apart. Clean up all the oil, put a new valve gasket in it. (There was some burn't oil deposits in the cylinder, near spark plug hole. I cleaned it all up. I put a new gasket in between carb and engine (carb gasket?), rebuilt the carb from kit, replaced all gaskets, main jet needle, etc. The carb is a Walbro WT-199. Replaced fuel line (there is only one) and replaced fuel filter (inside tank). New spark plug too.

Give it back to my uncle, the trimmer works great, he runs it for about 30 minutes when it suddenly dies, sounds like it is running out of gas, his words. He looks it is half full of fuel but fills it anyway, trys again but each time it starts to dies within a few seconds.

I test the compression (its an automotive one, so not great) and the thing has nearly twice the compression of my other trimmer that runs (honda 4 stroke).

I test the spark, I have great spark. Swap spark plugs...no change.

I can start it if it has been hours since it was used. I can get it to start for about 10 seconds, it quits. Then no matter what I can't get it started, unless I wait a few hours and then come back. Same thing starts once, then quits. Sometimes I can't even get it to start once.

I spray starter fluid in through the spark plug hole, put the plug back. Still can't start it (in this case I had managed a 10 second start, about 5 minutes before)

Crazy thing is I that when I go to start it the first time in hours I can start with the coke on or with it completely off. Some times the first start goes 30 seconds sometimes about 5 seconds.

I was planning to run it til it became hot and quit (like for my uncle) and then test for weak/no spark (due to coil module) or lose of compression. But since he used it has never run more than 30 seconds for me.

Last note, there is no clear scoring of the cylinder or piston.

Also the brand is Weedeater, I believe Poulan makes it. (not just using weedeater as generic term)

Any ideas?

 

Also fuel is fresh, and correctly mixed with 2 cycle oil.

I hope one of you guys is a mechanical genius, because this stupid trimmer is pissin me off

 

Does it smoke and stumble when it starts, or does it rev high and wane off?

 

No smoke or stumbling. I have to start it with throttle wide open, according to the manual and experience, so yeah it revs pretty high when it starts then wanes off.

Good to hear at least a response...Thanks.

 

I have had this happen on that style trimmer twice. Both times I fought it long enough to decide it wasn't worth it. I think the trimmer is getting air through a warped plastic crankcase cover or crankshaft seal, but I can't swear that's what caused it because I didn't fix them. The time required to repair was exceeding the value of the units. You might try spraying carb cleaner near the crankcase cover and crankshaft seal to see if it makes it run better. This unit has reed valves too, but I don't think that's the problem. Could be a carb issue... check the inlet screen, it may have stopped up. The material that weedeater used for their fuel filters would deteriorate and get sucked up into the carb and clog the screen. You can clean it and a few minutes later it's clogged again.

 

Yeah, I thought there was maybe a leak, so I switched out all the gaskets. No change...it really is crazy. It's nice to know I'm not the only one who has dealt with this, but sucks. I told my uncle it was time to replace it. Thanks for your help, and sorry it happened to you too.

By the way i changed the filter to a different type and checked the carb/cleaned it twice so I don't think that was the trouble in my case.

I think you are probably right about a leak in the crankcase, although I have no idea how that could happen. It not like the engine could really overheat and crack, at least from my understanding. The engine wasn't caked in mud or anything like that.

 

The rubber seal around the crankshaft can crack, dry up, shrink away, etc... Also the plastic cover on the crankcase can warp over time and leak. I remember this well because on the first one I spent a lot of time and got pretty frustrated with it. It was years ago and I didn't have all the parts and equipment in my shop like I do now. The second one quickly reminded me of the first one and I bailed out before I got too far into it with time that I couldn't bill out. I try not to work on these low end trimmers much anymore. If they need a primer or fuel lines, ok, but it's really easy to lose money on these when you start out putting fuel lines on, then the primer breaks, then the carb is clogged, then... and before long you have more time and parts in it than you can bill the customer for.

 

I was also about to give up on a 32 CC Craftsman WeedWacker as well. It worked fine last years. I'm pretty invested in it: I've got a couple parts machines around here; I rebuilt the Gear Box a couple years ago; I've got lots of special pre-cut heavy duty trimmer licorice; extra Primer Bulbs, Bearings, and Fuel Filters; and a bunch of other accessories . . . . but I was frustrated enough this past week to say "That's it !"

But as a final effort, I read something on here about forgetting about the High Speed jet and just focusing on the "Idle" to get control of that . . . . then you can work calmly with the High Speed Jet to get that right.

So I took both Needles out and cleaned them, and put them back in starting at ground zero, and then backed them out 2 and 1 half turns. That didn't work immediately, so I backed the Idle only out another full turn, and that got me started, after which I adjusted the Idle by ear and then worked on the High Speed for a few more fine tuning adjustments.

That did it . . . . I'm back in business !