I have an old blue super XL that would periodically not get enough gas and quit. It has gotten so bad that now it will only run for 10 or 15 seconds at 1/2 throttle before starving and quitting. I have changed gas filter, cleared the line from the tank, and cleaned screens in the carb to no avail. Next I will remove the carb, but am wondering what I should be looking for or may expect to find as the cause. I have never done much with small engines. Thanks
- Thread starter lbaker
- Start date
Mike(NEOhio)
Well-known Member
- Location
- Newbury, Ohio
Could be the fuel line is collapsing, had that happed on an XL-12. If you get into the carb, they're pretty simple. There's a thimble-shaped screen at the fuel inlet. May be pump diaphragm. Just get a kit for it. I found one at an Amish shop, about $7.
lynnvillekytractor
New User
Unfortunately, today's alcohol gasolines cause
most small engine carburetor troubles.
Preventively speaking, avoiding fuel with alcohol is
the best measure if possible. However, it is not
always possible to find gas stations that carry
alcohol-free fuel and the premix stuff is outrageous
ly expensive. So, the only alternative then is to use
additives in the alcohol gas to help with the issue.
Repairing the carb in these conditions requires a
rebuild kit for that specific carb along with carb
cleaner to soak the carb in and spray out the jets.
The gallon size carb cleaner comes with a basket
to place your disassembled carb in to soak. You
want to blow it out really good with air hose and
compressor. Don't want to put the nozzle against
the carb when blowing it out because some carbs
have pressed in brass orfices that can be blow out
of the carb by the intense pressure. Most of the
small engines that I have that need a rebuild
usually get a new carb because most of them can be
bought online cheaper than buying the kit and
supplies. Best wishes.
most small engine carburetor troubles.
Preventively speaking, avoiding fuel with alcohol is
the best measure if possible. However, it is not
always possible to find gas stations that carry
alcohol-free fuel and the premix stuff is outrageous
ly expensive. So, the only alternative then is to use
additives in the alcohol gas to help with the issue.
Repairing the carb in these conditions requires a
rebuild kit for that specific carb along with carb
cleaner to soak the carb in and spray out the jets.
The gallon size carb cleaner comes with a basket
to place your disassembled carb in to soak. You
want to blow it out really good with air hose and
compressor. Don't want to put the nozzle against
the carb when blowing it out because some carbs
have pressed in brass orfices that can be blow out
of the carb by the intense pressure. Most of the
small engines that I have that need a rebuild
usually get a new carb because most of them can be
bought online cheaper than buying the kit and
supplies. Best wishes.
Moonlite37
Well-known Member
Did you clean the exhaust ports? Leaking air filter, excessive oil in fuel mixture and improper type oil contribute to carbon deposits. These old saws called for a fuel with a lot more oil than modern saws and are more prone to carbon buildup.
BarnyardEngineering
Well-known Member
- Location
- Rochester, NY
Sorry, ethanol has absolutely nothing to do with this problem. 40 years of wear and tear on the original carburetor and fuel lines is the problem.
When you pull the carb apart you will likely find the diaphragm either torn or stiff as a board. This diaphragm pumps fuel to your carburetor.
When you pull the carb apart you will likely find the diaphragm either torn or stiff as a board. This diaphragm pumps fuel to your carburetor.
rustyfarmall
Well-known Member
Before you do anything else, loosen the fuel cap. If it runs then, you have found the problem.
Carb kits are easy to get. Likely has an HS Tillotson carb unless it was replaced with a new Walbro.
When I first worked as a tree climber and cutter for Asplundh around 1970 - all we had were the blue Homelites. Super XL,
XL12, XL101, etc. All pieces of junk by today's standards but considered pro saws at the time. Problems like you describe
are common. Bad fuel lines, bad crankshaft seals, etc. We had all those problems way before there was 10% alcohol in the gas.
By the way - I use that same 10% gas in all my newer saws with zero problems.
When I first worked as a tree climber and cutter for Asplundh around 1970 - all we had were the blue Homelites. Super XL,
XL12, XL101, etc. All pieces of junk by today's standards but considered pro saws at the time. Problems like you describe
are common. Bad fuel lines, bad crankshaft seals, etc. We had all those problems way before there was 10% alcohol in the gas.
By the way - I use that same 10% gas in all my newer saws with zero problems.
I agree. When our dealership changed our main brand from Homelite to Stihl around 1972, we had horrible fuel-line rot problems on the Stihl saws. By 1990, Stihl STILL had the problem but finally corrected it. Maybe they were getting their rubber hoses from China? Stihl Farm-boss 041 was the worst. I have many chainsaws and NO problems using 10% alcohol gas.
shaun wallace
Well-known Member
Key # 26 is gone. Little rubber valve comes in kit, have to remove welch plug to get to.
I assume you realize the crankcase has to be tight or it won't get gas? One common problem (among many others) with old
Homelites are crankshaft seal leaks. If a seal is leaking badly, it will not get gas because the fuel-pump won't work. If in
a repair shop - it is standard diagnostics to pressure-test the crankcase. If not that, at least pull the sprocket and clutch
off and inspect the seal on that side. Reed-valve also needs to be working. Most Homelites during that time did not have
piston-port sealing. They used reed-valves that can break off.
Homelites are crankshaft seal leaks. If a seal is leaking badly, it will not get gas because the fuel-pump won't work. If in
a repair shop - it is standard diagnostics to pressure-test the crankcase. If not that, at least pull the sprocket and clutch
off and inspect the seal on that side. Reed-valve also needs to be working. Most Homelites during that time did not have
piston-port sealing. They used reed-valves that can break off.
Angle Iron
Member
hey like to squeeze shut where the fuel line exits the tank and where it enters the carb air box.
Late 70's Pioneer 1200, 3370 and McCulloch 7-10. All worked fine with pump gas for years. Fuel lines were fine. The minute I added 10% ethanol fuel to these saws the fuel lines started to deteriorate and the Pioneer fuel caps swelled to the point Channel Locks were required to remove them 24 hours later. Don't tell me ethanol fuels are benign because I've fixed dozens and dozens of saws that prove you wrong. I believe the specific blends available to us locally have a large effect on the problems we see. If you run your saws dry, keep the fuel fresh and don't make a lot of demands, ethanol can be fine. But I can assure you that in my area, simply changing fuels to non-ethanol solves a lot of issues.
Agree. Seals dry out over time and if you don't replace them the saw will eventually lean out and destroy itself. The reed valve is a solid method of delivering fuel, but over time they can break...especially if some guy gets in there and start playing with things trying to "fix" something that isn't broken! :lol:
I choose not to believe the alcohol problems until I actually witness them. I have over a dozen saws sitting around with 10%
alcohol with no issues. I do have two crappy Poulan Pros that the fuel caps keep swelling up and I need pliers to get them
out. After someone else made the same remarks as you - I got a new cap and tried using pure gas at 75 cents more per gallon.
Cap still swelled up.
There indeed may be some old fuel lines around with materials that do not respond well to alcohol. I have not come across
any. I DID have that problem with rubber hoses on diesels with modern diesel fuel or bio-fuel.
Rotted fuel hoses were our #1 repair issue on chainsaws in the 70s-90s. Way before we had 10% alcohol added. We sold and
fixed Homelite, Stihl, Echo, Solo, Mac, Pioneer, and even Remington for awhile. I saw fuel line rot on any of them that had
fuel lines. Some also had vacuum hoses that did not carry gas and they rotted out just as fast. I am simply reporting on
what I have witnessed myself. If I ever come across a problem I can prove was caused by 10% alcohol - I will then believe
it.
alcohol with no issues. I do have two crappy Poulan Pros that the fuel caps keep swelling up and I need pliers to get them
out. After someone else made the same remarks as you - I got a new cap and tried using pure gas at 75 cents more per gallon.
Cap still swelled up.
There indeed may be some old fuel lines around with materials that do not respond well to alcohol. I have not come across
any. I DID have that problem with rubber hoses on diesels with modern diesel fuel or bio-fuel.
Rotted fuel hoses were our #1 repair issue on chainsaws in the 70s-90s. Way before we had 10% alcohol added. We sold and
fixed Homelite, Stihl, Echo, Solo, Mac, Pioneer, and even Remington for awhile. I saw fuel line rot on any of them that had
fuel lines. Some also had vacuum hoses that did not carry gas and they rotted out just as fast. I am simply reporting on
what I have witnessed myself. If I ever come across a problem I can prove was caused by 10% alcohol - I will then believe
it.
I understand completely JDEM. I didn't buy it either until I saw what just changing fuel did. I truly believe your local blends play a big part in this. I've gotten several Poulan Pros to repair and never saw the cap swelling problem, yet you have. I figure it's the specific blend doing it.
I the early 80's we were told by Jonsereds chief US tech guy that any type of alcohol in a 2 cycle was bad news. I was skeptical then, but I'm not now.
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