Who has freshened up a small 2 stroke motor? Advice?

[rang-a-stang]

I have had the same cheap/crappy 2 stroke weed whacker for about 20 years and I guess I should go through the carb or something. Are these little carbs worth rebuilding? should I just go get a new one? I replaced the spark plug a few years ago but that is about all the regular maintenance I have ever done on it. I use it for about 10 minutes every other week from early spring to late fall so it does not get a lot of use. With my son doing the yard these days, having a decent running weed whacker makes the battle to get it done a little easier to win.

Symptoms: runs pretty ok but its a bear to start without starter fluid. I have the idle cranked pretty high because it will not idle otherwise. It leaks gas from various places.

[Be from Be]

If it is 20 years old, it probably has breaker points. You should replace them, or at least adjust to specs.

[JeepsAndGuns]

A 20 year old line trimmer and it still runs. Wow, color me surprised.
I am a small engine tech. 95-99% of the time, it is not economical to try and rebuild/repair the carbs on small 2 cycle engines. (when I say small, I'm talking handheld equipment). Most are $30 or less (sometimes under $20) and are only higher if they are something rare or from a larger engine.
Most of these carbs have either check valves and/or very very tiny orifices. The check valves can leak, and the passages/orifices can get restricted or plugged up. They also have metering diaphragms that can harden and stop working.
Also the engine itself can have issues that cause running problems. 2 cycle engine have sealed crankcases. If there is a air leak, the engine will run poorly. They can leak around the carb gasket, crankcase gasket, and the crankshaft oil seals. All these can degrade after age and use.
Most of the time, it is more economical to purchase a new trimmer.

[babywag]

last small engine carb issue i dealt with was cheaper for new carb than a rebuild kit...

[Driftwood]

I suspect its time you upgrade to a Stihl.

[ZackN920]

First off, does the original carb have any mixture adjustment screws on it? If it does, it sounds like you need to enrich the L screw a bit. Give it some more fuel at "low" speed/idle. As to the starting problem, does it have a primer? How about choke? Both? Bad primer bulbs can cause serious issue for starting especially if they leak. Usually gasoline flows through these bulbs (on the 2 cycles) while the engine is running(and you did mention leaking gas).

If it has L and H fuel/air adjustment screw's than I would get a carb kit and go through it. It's actually quite easy. Do it at a bench- go slow and keep track of all the parts during disassembly. Clean it with carb cleaner, blow it all out with compressed air and re-assemble with new gaskets. Oh, and keep an idea as to where your settings are so you can get it back to where it was for getting it started, than you can tune it from there.

BUT, if it has NO adjustments for mixture and only has an idle adjustment than you may be better off replacing it. Unfortunately, the replacements are most likely junk that's made in china that will probably only last 5 years at a time before you start having problems again. What happens with the carb is that they usually wear a bit at the throttle shaft and that will let in a little extra air which leans the mixture. On old carbs, this is no problem. You just re-tune it but on modern JUNK, the lean mix cant be tuned out so you have an engine that runs like crap or wont run at all. The company then wants you to buy a new machine...

If it were me, if the carburetor has mixture screws I would get a carb kit. Yes, you can replace it-sometimes for just a bit more than the kit but most replacements are junk. I would never do it-unless it was un-adjustable.

As for the original question of "Who has freshened up a small 2 stroke motor?" I have, more so along the lines of that I did a full rebuild on one of my homelite trimmers. My model 165, which is 41 years old this year and gets HEAVY use. (I do a lot of grounds keeping for people)It was still running too, I just got sick of it knocking and didn't want to blow it up because of the then loose bearings. I did it because I cant stand using any other style of weedwhackers, I usually get a back ache or burn my arm on the engines.
I've got a lot of OLD equipment(25-60 years old[ha, most this stuff is older than me!]) I use for work and there for, that I keep running. Most of the time though, I don't ever need to touch the stuff.

[ZackN920]

If it is 20 years old, it probably has breaker points. You should replace them, or at least adjust to specs.

WHAT on a 2 cycle?!

Naw, you not going to find points on any single cylinder 2 cycle. They all use magneto ignition and spark when the magnet on the flywheel goes by. That's also why the flywheel only goes on 1 way to keep things aligned/ in time.

That, and anything from 20 years ago wouldn't have points anyways, heck even 30 years ago they most likely wouldn't have it. My newest machine that might use points would be my 1984 Briggs and Stratton powered push mower. I haven't needed to take it that far apart though to find out for sure Some of them B&S engines already had solid state ignition at that point in time. If it's not that, then next in line would be my 1969 Simplicity 3112.

A 20 year old line trimmer and it still runs. Wow, color me surprised.
I am a small engine tech. 95-99% of the time, it is not economical to try and rebuild/repair the carbs on small 2 cycle engines. (when I say small, I'm talking handheld equipment). Most are $30 or less (sometimes under $20) and are only higher if they are something rare or from a larger engine.
Most of these carbs have either check valves and/or very very tiny orifices. The check valves can leak, and the passages/orifices can get restricted or plugged up. They also have metering diaphragms that can harden and stop working.
Also the engine itself can have issues that cause running problems. 2 cycle engine have sealed crankcases. If there is a air leak, the engine will run poorly. They can leak around the carb gasket, crankcase gasket, and the crankshaft oil seals. All these can degrade after age and use.
Most of the time, it is more economical to purchase a new trimmer.

Why is that a surprise? I see old equipment in use a lot around here, including my self.

I agree with ya there. Shop rate is way too high to be economical to have to pay to go through the carb. Much anything else with small engines. If ya do it yourself than yea, you can fix it cheap. Have a shop go through it...pfff might as well buy a new machine because you'll pay the same price in the end. What can you expect when the shop wants $80 an hour No wonder why I taught myself to fix ALL of my own stuff, whether its electronics or mechanical or all the junk in-between!

[rang-a-stang]

Copy all. Looks like Amazon has kits with a Carb, spark plug, fuel filters, and fuel line for less than 20 bucks. I'll pull mine apart and see if that's all it needs. If it needs more than that, it's going in the trash and i'll get a new one...

[Ristow]

Who has freshened up a small 2 stroke motor?

Does an 8V92 Detroit count?

[FleetFox]

yes. don't post pictures though, just audio.

Fleet Fox

[ShagWagon]

Be sure to check the warranty. I bought a new oem Honda carb for my pressure washer and it was the wrong one and had a badly bent throttle. I bent the throttle back but it was for an auto choke and not a manual choke so the choke wouldnt stay on. What a pain! And my model number was listed as one that it fit.

But the warranty was for a week from purchase date and they wouldnt take it back so I got screwed out of $30

[Ristow]

yes. don't post pictures though, just audio.

Fleet Fox

photobucket destroyed every video in my library. all are dead links now.