Need a little small engine assitance, if possible...

-
65LoveAffair

65LoveAffair

Whovian
Joined
Aug 24, 2010
Messages
2,300
Reaction score
283
Location
Decatur, IL
I have a Snapper 28cc gas trimmer that is about 3 years old. I use it maybe 3 or 4 times a summer, at most. I went to start it up today, and at first it ran fine. I got a little trimming done, and then it started bogging down when I hit the throttle. Eventually it died. It started right back up and idled fine, but when I hit the throttle it died again. I thought maybe, even though I put Stabil in the gas, that it might be a fuel issue, so I disposed of the fuel in the tank (properly!) and put in some Trufuel 50:1 I bought at Farm & Fleet. It's 93 octane ethanol free with oil premixed into it. I changed the spark plug and I also checked the air filter. It was fine. I started the trimmer up, and it ran fine again until it warmed up. At that point it bogged down and died again. The only adjustment I can make on this trimmer is the idle speed. Everything else is set at the factory and not adjustable, supposedly. I really haven't investigated this. From what I've seen online, people with this problem have fixed it by things as easy as running Seafoam through the gas tank and as drastic as replacing the carburetor. While replacing the carburetor is cheaper than buying a new trimmer, it's a little cost prohibitive at the moment. Anybody have any suggestions? Also, if I put Seafoam in the gas tank, is that going to mess up my fuel/oil ratio? Thanks in advance.
 
I have found carbs get all gummed up on some of mine and just take the carb apart and clean it out with solvent and put it back together...

If that don't work, I take it in to the service place...
 
I have had this happen to me a bunch of times with multiple 2stroke equipment in the shed, due to the ethanol in the fuel nowadays. Krazykuda is right, as to start by taking the carb off, disassemble, give it a good cleaning , and blow out the passages with compressed air. This whole process usually takes no more than 20 -30 minutes , with minimum hand tools.. While it is off, give the fuel lines a check over, as I have had them hardened and broken in the fuel tank. If you need to replace them, they are readily available at most auto parts stores as well as lowes and home Cheapo. After the installation adjust the high speed mixture setting so no bog is evident on acceleration . If mixture settings are not allowed to be adjusted, simply look up the make and model of the gas trimmer and get the carb number,just search carb for snapper model # , order a replacement on eBay or Amazon ( I paid $20 for a new one for my crapsman chainsaw) they have the adjustment screws access able,if they offer the adjustment tool , which is a female spline screwdriver get it as no shop will sell you one, I ordered a carb that had one, I think it was $3 more.
 
70dustah said:
I have had this happen to me a bunch of times with multiple 2stroke equipment in the shed, due to the ethanol in the fuel nowadays. Krazykuda is right, as to start by taking the carb off, disassemble, give it a good cleaning , and blow out the passages with compressed air. This whole process usually takes no more than 20 -30 minutes , with minimum hand tools.. While it is off, give the fuel lines a check over, as I have had them hardened and broken in the fuel tank. If you need to replace them, they are readily available at most auto parts stores as well as lowes and home Cheapo. After the installation adjust the high speed mixture setting so no bog is evident on acceleration . If mixture settings are not allowed to be adjusted, simply look up the make and model of the gas trimmer and get the carb number,just search carb for snapper model # , order a replacement on eBay or Amazon ( I paid $20 for a new one for my crapsman chainsaw) they have the adjustment screws access able,if they offer the adjustment tool , which is a female spline screwdriver get it as no shop will sell you one, I ordered a carb that had one, I think it was $3 more.
Click to expand...
if u have used ethanol fuel in the past, and left it in the tank for long periods of time, u might want to check the fuel hose, they get soft and collapse. best to always dump that crap before putting it up.
 
On my Stihl I just unscrew the muffler and decarbon it with my wire wheel brush. It does have the spark arrestor on it and that is what clogs. Google your trimmer and watch some videos
 
73hcode said:
On my Stihl I just unscrew the muffler and decarbon it with my wire wheel brush. It does have the spark arrestor on it and that is what clogs. Google your trimmer and watch some videos
Click to expand...

Yessiree! They are putting BS wire mesh screens in the mufflers now. They eventually get clogged up. I took mine OUT of the Stihl weed eater I have and it gets it done now.
 
Thirds on cleaning that spark arrester screen in the muffler, but I wouldn't toss it unless you're willing to pull the limiters on the carb screws and diddle the mixtures. The epa runs them wicked lean as is and the spark arrest screen creates enough back pressure when clean to keep them jetted properly.
The clogged screen default richens the mixture; a safe operating condition.

Tossing it risks leaning the motor out. Not good when it's a heat prone motor running wot most of the time.


Based on your description of the running condition, is very likely there's a very fine fuel screen just past the fuel inlet on the carb, and it's probably got a clearish layer of Schmootz on it. I would NOT disassemble the entire carb. Just pull the top plate to find that screen, blow the gunk off with carb cleaner, and reassemble.
don't lose the wee screen.
 
So just to make it easy;
The issue only comes when the engine is fully warmed up, and it idles fine even hot. The only issue is that it won't take throttle when hot.
If that is correct, them at least the low-speed circuit is fine, and it is usually the first to get gummed up as it has the smallest passages.
You said it bogs when you "hit it." What happens if you try and rev it up slowly, when hot?
What happens when you "hit it" with a cold engine?
 
AJ/FormS said:
So just to make it easy;
The issue only comes when the engine is fully warmed up, and it idles fine even hot. The only issue is that it won't take throttle when hot.
If that is correct, them at least the low-speed circuit is fine, and it is usually the first to get gummed up as it has the smallest passages.
You said it bogs when you "hit it." What happens if you try and rev it up slowly, when hot?
What happens when you "hit it" with a cold engine?
Click to expand...
If I go slow, it still bogs down but it takes longer to do it. The trimmer head never gets up to speed, and it will eventually die when it gets enough throttle. When it's cold, it runs great. No issues. Once warmed up, I may as well just pull the weeds by hand.
 
And the trimmer head free wheels with the engine off/idling?, and the gearbox isn't blazing hot?

A)Running great when cold tells me she's not lean at that time, and so it would seem that the carb is ok.
B)Bogging down with slow throttle,(in conjunction with A) when hot tells me that she may in fact be rich. So the first go to is sparkplug cuz the plug rarely lies. If she's sooty, swap her out and clean the air filter, and make sure the choke system is NOT ACTIVATED.
C) a bog when you hit it is usually a transition problem. Transitioning from the low-speed/idle circuit to the power circuit. Your only adjustment for this may be the idle speed, crank her up a bit, to just below where the clutch starts nipping at the powerhead.
 
Last edited:
AJ/FormS said:
And the trimmer head free wheels with the engine off/idling?, and the gearbox isn't blazing hot?

A)Running great when cold tells me she's not lean at that time, and so it would seem that the carb is ok.
B)Bogging down with slow throttle,(in conjunction with A) when hot tells me that she may in fact be rich. So the first go to is sparkplug cuz the plug rarely lies. If she's sooty, swap her out and clean the air filter, and make sure the choke system is NOT ACTIVATED.
C) a bog when you hit it is usually a transition problem. Transitioning from the low-speed/idle circuit to the power circuit. Your only adjustment for this may be the idle speed, crank her up a bit, to just below where the clutch starts nipping at the powerhead.
Click to expand...
The spark plug is brand new. I just put it in yesterday, gapped to .025" as per the user manual. The trimmer doesn't really have an adjustable choke, only the lever I flip into the "Start" position when trying to start it cold. While trying to fix this yesterday, I adjusted the idle speed screw from all the way in to barely hanging on and there was no real noticeable difference. I had to put it away before I either threw it or started slamming it into the ground repeatedly as hard as I could.
 
73hcode said:
On my Stihl I just unscrew the muffler and decarbon it with my wire wheel brush. It does have the spark arrestor on it and that is what clogs. Google your trimmer and watch some videos
Click to expand...

RustyRatRod said:
Yessiree! They are putting BS wire mesh screens in the mufflers now. They eventually get clogged up. I took mine OUT of the Stihl weed eater I have and it gets it done now.
Click to expand...

Ding ding ding, that's where I would look, I had to remove them on all 4 of mine that I used for the business.

Thank California for that!
 
Well that's cool but what did the old plug tell you?
If it was not sooty, I suppose you could check the spark-arrestor, but since it runs great when cold, that wouldn't be the first place I'd look.
If the old plug was not sooty, then my first go-to would be the spark energy. I would check this first cold so you know what it should look like. Then again after it starts acting up.

I had a similar issue with a Troy-Built. It ran great when new, but the following year, I too was tearing my hair out. I found the hi-speed mixture screw hiding under a plug.After I sawed the plug off, I still had to put a screwdriver slot into the screw. But even that circuit was lean. I finally had to tear the carb apart,find the power restriction,and drill it out a hair. Then finally I had a trimmer.So I thought. Then the dumb thing stripped the plastic power-head drive out, so now the power head was in full-time freewheel mode.sooooo
I had to drill out the shaft, and the head,and install a steel drive pin. Cuz you know why? It would seem they don't make service parts cuz there are none available anywhere within a 50 mile radius of me. Buyer beware; no more Troy-Built anything for this cowboy.
But if you buy a cheap throw-away trimmer, every supply house around has parts for those ........
 
Last edited:
My trimmer got to be hard starting. Like someone else said, ethanol deteriorates rubber. Check fuel line, also maybe the vent on the gas cap plugs up as I had that happen to a snowblower. Started and ran fine for 10 minutes then crapped out. Opened tank to check and it ran again for ten minutes. Put vent hole in paper underneath cap and voila! Runs great.
 
My apologies to all, I haven't had any time to check the trimmer the last day or so. My dad was in the hospital and just got back out today. Hopefully I'll get a chance to check it out tomorrow. Well, today now. Just a quick question, though. Something that I've been wondering about. When I took the gas cap off to drain the old fuel and put in the TruFuel, the cap retainer had broken off and was in the tank. Does this have anything to do with the vent in the cap, or is it just a retainer? Here are a couple pictures of my exact model's cap:

Cap-705525-05048466.jpg
Cap-705525-05048487.jpg


It broke up inside where it looks like splines in the center of the second picture. That whole part just detached from the inside of the gas cap. I was able to fish the broken piece out, so it's not still in the tank. I'm just curious if it is part of the vent and is possibly a big part of my issue.
 
Yes that's all part of the vent. But if it falls apart the vent will still work; now it will just leak.
If you look at the top you will see a tiny pinhole in it, and that is the hole where air is supposed to enter the tank. In the lower pic you see the backside.The splined thingy is just the retainer system for anti I-lost-my-cap system. It matters not to the vent if it's there or not,however there is usually a little thin foam puck trapped by that retainer in the cavity above it. And that foam is kindof a one-way valve. It allows air in, and vapor pressure out, while not allowing liquid fuel to leak alll over during the course of operation and especially when you hang it up afterwards.
It may not be broken as much as just it has just come apart. Go look for the foam puck and just press it all back together.In lieu of a puck, I have seen a metal disc in there, sometimes concave/convex which may need to be oriented correctly.
Louie70 talks about a paper gasket with a hole in it. That's the same kindof deal; it allows air in and acts as a splash baffle to not allow liquid fuel out. but your cap appears to be a little more sophisticated,lol. The paper thing was used for many decades.
 
Last edited:
Yeah I know I harp on that a fair bit. But that's what I see a lot of. And while string trimmers don't have transfers per se, with just a hi and a lo speed circuit You still have to transition from one to the other, And if the throttle is too far closed at idle, then it will be difficult.

I get it tho, all in good fun.
 
just buy a new carb, stick it on and you are good to go. They are not expensive at all.
 
Whelp, it appears that the operation was a success, but the patient still died. I finally got a chance to dig into the trimmer this past weekend. I took it apart, cleaned all the parts, and put it back together and reinstalled it on the trimmer. No joy. It just didn't want to stay running. I think I am going to have to get a new carb. Not sure what's going on with this one. The only other thing I can think of is to get a carb rebuild kit and replace all the gaskets and seals, and if that doesn't work, then get the new carb. Thanks for all the help and suggestions.
 
If you put the carb in a strong cleaner made for that purpose, and left it in there for the allotted time, then the carb may not be the issue.
At this point I would be going back to basics; a compression test and a suction test. Just like your auto engine, these little guys are air-pumps. They suck air in and they push air out. So remove the carb, put your thumb over the hole and pull the starter-rope. It should try to suck your thumb in. If it doesn't, pull the muffler off and try it again. If the suction is now harder, then clean the muffler out. If no difference, and the compression is well over 100psi, then the crankcase may have developed a leak. But if the compression is under 90 then the ring is not working, time for an inspection. It may just be stuck. Or the cylinder may be scored. With the muffler off you should be able to inspect the cylinder through the exhaust port.
Good luck.
 
AJ/FormS said:
If you put the carb in a strong cleaner made for that purpose, and left it in there for the allotted time, then the carb may not be the issue.
At this point I would be going back to basics; a compression test and a suction test. Just like your auto engine, these little guys are air-pumps. They suck air in and they push air out. So remove the carb, put your thumb over the hole and pull the starter-rope. It should try to suck your thumb in. If it doesn't, pull the muffler off and try it again. If the suction is now harder, then clean the muffler out. If no difference, and the compression is well over 100psi, then the crankcase may have developed a leak. But if the compression is under 90 then the ring is not working, time for an inspection. It may just be stuck. Or the cylinder may be scored. With the muffler off you should be able to inspect the cylinder through the exhaust port.
Good luck.
Click to expand...
I can do the suction test, but I don't have a compression tester. I'll see what I can do with this, but it'll probably be this weekend. Thanks for the suggestion.
 
65LoveAffair said:
I can do the suction test, but I don't have a compression tester. I'll see what I can do with this, but it'll probably be this weekend. Thanks for the suggestion.
Click to expand...
My trimmer acts like it has a bent rod, wonder if the cable has seized .
 
You must log in or register to reply here.
-

Back
Top