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Gasoline Varnish Remover Products

08/19/2012 4:13 PM

Hiya, wondering if some you shade tree mechanics out there can come to my rescue!

I has a 4-cycle gas powered 8.75 Hp B&S engine on my power washer. I haven't used it in the last 2 years. Today, when I went to fill up the gas tank I noticed that the old gas has evaporated and deposited what looks like gas varnish. After filling up the tank with new FRESH gasoline the engine would not kick-over and start. This has never happened with this particular engine before.

But if I sprayed engine starter fluid into the carb it started and ran for a very short time. To me this means that the varnish buildup has clogged the line and possibly the fuel line shut off valve.

Does anyone have a liquid varnish remover product they can recommend that can be added to the new gas in the tank......it needs to dissolve the varnish buildup. I'm not looking for spray cans of carb cleaner. Ditto with fuel injection cleaners. What I want is a can of cleaner fluid with a sizable volume, that can and will clean this MF'ing varnish in a day of so!

Any takers?

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Pathfinder Tags: engine starting problems gasoline varnish small 4-cycle engines
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#1

Re: Gasoline Varnish Remover Products

08/19/2012 5:58 PM

I've never found any product that worked without disassembly and manually cleaning all the fuel passages.

When the varnish/gunk build-up reaches this point (no start/run), the fuel passages may be completely clogged shut. If fuel can't get through, then the solvent can't either.

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#2

Re: Gasoline Varnish Remover Products

08/19/2012 6:02 PM

Your biggest problem isn't in the fuel tank, the fuel line, or the shut-off valve. It's in the carburetor. Just putting something in the tank at this stage won't help that, because it can't get past the gas already in the line to the carb.

What might work. . . SeaFoam seems to be the current 'hot' product (Mechanic in a Bottle is also pushed hard.). I used it (SF) in my neighbor's pressure washer and it seemed to work. What you want is as strong a mixture of SF in the carb as possible. So pour out (or drain) the gas in the tank. That is probably a float carb, so loosen the float bowl bolt and drain all you can from there. While you're that far, it's better if you remove the bowl and clean as much varnish off the bowl and float as possible. Then put it back on. Now, pour SF in the gas tank so that it will fill up the carb and let it sit a while, maybe a day or 2. If you've been living right (except for leaving gas in your PW), you may be back in business. Pour in a little gas and see if it'll start. I don't know if it'll run on 100% SF. With my neighbor's PW, I cleaned the carb and got it running, but the idle circuit was still plugged. I put about 1/3 or 1/2 SF in the gas and after I ran it about an hour while cleaning my patio, it idled like a lamb. Good luck. If that doesn't work, I'm afraid you're looking at a carb cleaning. Don't forget to check that your fuel filter, if you have one, lets flow into the bowl.

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#12
In reply to #2

Re: Gasoline Varnish Remover Products

05/29/2013 5:11 PM

seafoam works!!!!! wow. but it takes time. be patient. what helps is if you have a drill motor start feature. this will allow the seafoam to get into the carburetor and do its work. but I agree that if the carburetor is completely clogged , that then this calls for either a replacement or disassembly of carburetor. but before I would disassemble , I would suggest that you get a large glass jar and pour the seafoam into the jar and then allow the carburetor to completely be submerged into the jar and seafoam. this will allow the seafoam to slowly enter the carburetor and dissolve the clogged areas with the shellac and/or lacquer buildup. remember , that there is a learning curve to disassemble these tiny carburetors that come on these small 2 cycle motors. also all of this can be prevented if we would only drain the fuel tank in the fall and fill the tank with alcohol during the winter.

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#3

Re: Gasoline Varnish Remover Products

08/19/2012 6:38 PM

i've used lacquer thinner with exllecent results. fill the tank with thinner,then open the carberator bowl drain plug until there's a steady flow. close the plug and let it set for a few days. loosen the carberator bowl plug to drain the thinner then flush it with gasoline. that should desolve the varnish that's causing the problem.

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#4
In reply to #3

Re: Gasoline Varnish Remover Products

08/19/2012 7:19 PM

I've used it in the gas a few times and to clean parts, but you have to be careful. It can dissolve gaskets, hoses, plastic parts, even plastic fuel tanks if you leave it too long. It does work well and fast if you're careful.

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#9
In reply to #4

Re: Gasoline Varnish Remover Products

08/20/2012 5:11 PM

a good point. lacqurer will ruin rubber parts in short time. it would be best to disassemble the carberator. soaking the carb in thinner is still a good idea. remove all the needle valves, orffices and seats then throw everything in steel container with thinner and let it soak for a few days. blow out all the passages with compressed air then reassemble it with a rebuild kit.

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#10
In reply to #3

Re: Gasoline Varnish Remover Products

08/20/2012 5:51 PM

p;s; it could just be a stuck float needle valve. try blowing down the gas line. you might have to use "low" pressure compressed air to free it. remove the gas bowl bolt first or the bowl itself.

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#5

Re: Gasoline Varnish Remover Products

08/19/2012 10:22 PM

Some great answers guys. Thank you!

I'm just wondering why the engine will run (even for a short moment) with the engine starter fluid shot into the carb. Doesn't that demonstrate that the carb isn't affected by a varnish buildup and therefore doesn't necessarily mean that the carb needs rebuilding?

As long as I squirted in starter fluid into the carb the engine ran smoothly. When I stopped spraying the engine sputtered and quit. Also, no amount of pushing the fuel primer bulb delivered fuel....the engine would not start of remain running.......so it seems to me that the clog is either in the tank or between the tank and the carb.....correct assumption then?????

I don't believe there's an inline fuel filter as far as I know....I didn't remove the plastic cover plate that protects the carb.

BTW, in the tank what type of fuel pickup would be present, or is it just a straight piping outlet where the rubber fuel hose is attached (on the exterior bottom)?

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#7
In reply to #5

Re: Gasoline Varnish Remover Products

08/20/2012 5:32 AM

The reason it runs once you've given it a sniff of starter fluid is that you're actually bypassing the carb's internals and the starter fluid is vapourising in the manifold.

Once the varnish has flowed through into the carb's infernals then you have to do the heavy maintenance. Pull the carb down and clean it out thoroughly, and clean out all the goo out of the tank too. It's a PITA but it's the only way.

Small motors are notoriously unforgiving when it comes to fuel quality especially with the dodgy stuff that gets served up these days.

Kranky Kev my local Mower Mechanic tells me that when you're done using a power tool you should drain the fuel out. Since I was given (and followed)that nugget of wisdom I've not had any grief with my yard tools.

The (housebrick) filter sits ontop of the fuel tap usually its not serviceable beyond soaking in carb cleaner and reverse blowing. They seem to come in 2 flavours, a fine mesh screen or a sintered bronze lump. This also operates as the fuel pickup.

Be aware that should you use E10 fuel it will exasperate any in any fuel system related issues especially in small motors.

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#8
In reply to #5

Re: Gasoline Varnish Remover Products

08/20/2012 5:33 AM

"As long as I squirted in starter fluid into the carb the engine ran smoothly. When I stopped spraying the engine sputtered and quit. Also, no amount of pushing the fuel primer bulb delivered fuel."

You answered your own question -- the engine is running on the starter fluid. Since pumping the primer bulb doesn't work, then no fuel is getting into the carburetor. Disconnect the line from the carb and try the primer bulb. If fuel comes out then the blockage is in the carb. If fuel still doesn't flow, replace the line and clean out the primer. If it still won't run then the carb needs cleaning.

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#6

Re: Gasoline Varnish Remover Products

08/19/2012 10:43 PM

Been there, done that. The only way to get it going again is to remove the carburetor and disassemble it by removing the bowl bolt. When you do you'll notice a few very small bore holes which have to be cleaned out, there may even be one in the bowl bolt running through its center plus a hole in its side.

The float has to pivot freely and then there's the hole that the float valve covers. Don't forget to back out the idle and high speed jet needle valves and clean those passages also.

Sometimes you can get lucky with a pressurized carb spray and blow these passages clean but I've had to resort to fine wire to open the passages enough to get the cleaner in there and pass through. You can try soaking the whole thing in Sea Foam for a few days with the bowl cover off, perhaps all those passages will clear on their own.

One thing you absolutely don't want to do is put anything into the tank if it's plastic, I had a B&S tank turn to Swiss cheese in a matter of minutes! The tank held the cleaner just fine, but when I put the gasoline back in, a series of chemical stress cracks appeared everywhere and it simply leaked right out. That tank will cost nearly $45 new, but your local small engine repair guy might sell you a used one for about $15-20.

Good luck, remove your contact lenses, and don't forget to wear your safety glasses.

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#11

Re: Gasoline Varnish Remover Products

08/20/2012 5:57 PM

always drain the carbarotor and tank while in storage or use a gas stablizer.

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