Chainsaw Repair

Chain - Grinders - Filing - Wood Milling - Tools - Welding - Machinist - Mowers - Tillers => Mowers Tillers Tractors etc => Topic started by: 3000 FPS on May 14, 2016, 08:39:01 pm

Title: Another 4 stroke trimmer.
Post by: 3000 FPS on May 14, 2016, 08:39:01 pm
So I have another Troy built 4 stroke trimmer and yes it is another freeby.   
The carb on this is Walbro WYL 187.   
So instead of rebuilding the carb I decided to try one of those Chinese knock offs. a Ruixing.

The carb was very cheap as in not much money.   I put it on and the trimmer starts up real good and idles good and run at half throttle real good.
Go to full throttle and it dies.   I try adjusting it but no good.

So I take the carb apart and find the main jet and I have these very small drills that I used for watch making.   I drill the main jet out and put it all
back together.   Bingo got wide open throttle now.    Trimmer idles good and accelerates good.    Just passing along some info.
Title: Re: Another 4 stroke trimmer.
Post by: 660magnum on May 14, 2016, 09:08:44 pm
GTK
Title: Re: Another 4 stroke trimmer.
Post by: dannyupsolate on May 15, 2016, 01:02:44 pm
good to hear someone  is smart enough to get one to run. please come to alabama and fix my six ;D
Title: Re: Another 4 stroke trimmer.
Post by: Cut4fun . on May 15, 2016, 01:41:14 pm
Nice fix Roger. 

Still only 4 stroke trimmer I had come in was a guy running 2 stroke mix in it.  He gave it to me free.  Changed plug, flushed it good and gave his trimmer back.
Told him what he was doing to make it not run.
Title: Re: Another 4 stroke trimmer.
Post by: dannyupsolate on May 31, 2016, 06:19:19 pm
anyone rebuilt the wyl carburetor did it turn out ok.
Title: Re: Another 4 stroke trimmer.
Post by: 3000 FPS on June 01, 2016, 05:39:02 am
anyone rebuilt the wyl carburetor did it turn out ok.

I have rebuilt a few of the WYL series Walbro carbs with no problems.   The diaphragms get stiff in them just like any other carb.
Title: Re: Another 4 stroke trimmer.
Post by: dannyupsolate on June 01, 2016, 05:23:11 pm
was wrong thought wyl and wyla used same kit. k1wyla is kit for wyla. cheapest i found is 10 bucks shipped for 1 maybe they will combine shipping for 6. good to hear they rebuild ok.
Title: Re: Another 4 stroke trimmer.
Post by: 3000 FPS on June 02, 2016, 02:13:44 am
When rebuilding those carbs just be careful with the main jet where the plastic needle comes down into it.    That little brass jet has a tiny o-ring on it that is used to seal it from leaking fuel.    Some kits come with that o-ring so that you can replace it.   Just make sure the jet is seated all the way down if you take it out and replace that o-ring and make sure the hole in it is clean.
Title: Re: Another 4 stroke trimmer.
Post by: dannyupsolate on June 02, 2016, 06:35:09 pm
ordered 6 k1wyla  walbro kits from mowers4u on ebay 28 bucks shipping and all. These are not available aftermarket. fits some 4 cycle trimmers and mini tillers mtd/ryobi family.
Title: Re: Another 4 stroke trimmer.
Post by: Chris-PA on June 03, 2016, 09:10:04 pm
How are these Troy Bilt 4-strokes?  They are rather appealing to me and I might go that way if I get another trimmer.
Title: Re: Another 4 stroke trimmer.
Post by: dannyupsolate on June 03, 2016, 09:17:16 pm
the top mount pull start is a sad joke on the new engine. plastic flippers mounted to thin sheet metal fan.
Title: Re: Another 4 stroke trimmer.
Post by: 3000 FPS on June 05, 2016, 10:52:31 am
The ones I have worked on seem to have a lot of torque and do not bog down as much in heavy grass or weeds.
They are a lot heavier then the 2 stroke trimmers and if used for a long time it can be a noticeable difference.
You have to be careful how much oil you run in them because if too full the crank case breather will push the oil into the air filter.    I have also run into some plastic cams on those which did not impress me.   The 2 strokes are easier to work on.
Title: Re: Another 4 stroke trimmer.
Post by: dannyupsolate on June 05, 2016, 06:57:09 pm
http://wem.walbro.com/distributors/servicemanuals/WYLseries.pdf  diagram of a rotary barrel carburetor.
Title: Re: Another 4 stroke trimmer.
Post by: 3000 FPS on June 06, 2016, 12:44:20 am
http://wem.walbro.com/distributors/servicemanuals/WYLseries.pdf  diagram of a rotary barrel carburetor.

I read that when I first started working on those carbs.    Some very good information there.