Homelite SXL-925 running hot - boiling fuel

[Mike mandry]

I have a 925 project I just finished up.

I ran it last week for a few min & it did fine.

Yesterday, I cut a large stump for a friend & it got real hot real quick. it was about 85 outside

It has a fresh carb job. New fuel line & filter, new tank vent in the fuel cap(working well) running a 20" 3/8 with an 8T rim.

It got hot enough to boil the fuel (fresh 91 octane @ 32:1 with MX-2T)

I pulled the plug & it was WHITE. Fearing the worst, I pulled the muffler & everything was OK

Carb was set @ aprox 1-1/8 turns open on the hi side & it sounded & ran great before it got hot. It started to run funny at full throttle (I think it was vapor locking)

Anyway, the saw is clean & everything seems to be in order.

It does not seem to have an air leak (idels fine & etc...)

I have 3 of these saws & have never had anything like this happen to the other two.

I ran it this morning & richened it up a bit. It seemed fine, but it did get hot, esp. around the tank area.

I even went so far as to run it so rich that it ran like crap & it still ran hot.

My neighbor has an infra red thermometer that I am going to borrow later today just to see how hot its getting.

Anyone have any ideas ???

 

[HiOctane]

I would say its "normal" if the gas is boiling in the tank while you are cutting big stump.Dont forget the tank is in metal ,a lot more conductive to heat than plastic tank.your tank is built arond the crankcase(very hot ).Your tank also is a lot more"enclosed"around the engine than newer models like Stihl or Husqui were they are more distant from engine and also in plastic,then less conductive to heat.Run it on the rich while cutting stumps or firewood to avoid seizing.

 

[Bob Wright]

It will do better this winter. Typical hot day and boiling gas, mine does it too...Bob

 

[Mike mandry]

The stump I was cutting was large, about 32" or better. However, it was probably half rotten.

the saw blasted through it w/o even trying.

Lately I have been tuning my carbs by the look of the spark plug after I set it the best I can by ear.

I am always careful to run them slightly on the rich side. never cooked one yet & hopefuly I never will.

For some reason, this one really bugs me.

 

[Al Smith]

A lot of the older Homies are gas boilers for some reason or another.I've got a pair of Lombards which are Homelite take offs ,that do the same thing.It's just the nature of the beast,I suppose.

 

[Patrick62]

I have one like that.

All metal case, and the gas tank has a common wall with the crankcase. Eventually, the gas boils. Saw seems to work okay in spite of it, but I can not shut it off as it will not re-start (vaporlock). Unscrewing the fuel cap has resulted in a 2 foot gyser of fuel!!!

This was one of the reasons I started using the ol' mans 041...

-P

 

[weimedog]

I had a XL-12 that boiled gas...I cleaned the fins and ran things a richer. It boiled less but still did once in a while. None of my 800, 903, 925's have ever boiled fuel. A white plug is caused by something. Possibly the timing is off a bit even though that would be hard to accomplish. Maybe a partially sheared woodruff key on the flywheel? Too hot a spark plug? Could be mixture issues. Too lean a mixture because of fuel supply issues? Maybe when the Saw is on the side its Fuel line & filter don't get to the bottom of the fuel tank. Maybe that carb doesn't pump well enough at RPM & Load and needs freshening. Maybe a main seal is allowing a bit of air by at RPM and leaning things out a bit. Maybe the fuel supply line is partially plugged..bottom line is I wouldn't accept that those 82cc Homie's boil without a solvable problem.

 

[Mike mandry]

I had a XL-12 that boiled gas...I cleaned the fins and ran things a richer. It boiled less but still did once in a while. None of my 800, 903, 925's have ever boiled fuel. A white plug is caused by something. Possibly the timing is off a bit even though that would be hard to accomplish. Maybe a partially sheared woodruff key on the flywheel? Too hot a spark plug? Could be mixture issues. Too lean a mixture because of fuel supply issues? Maybe when the Saw is on the side its Fuel line & filter don't get to the bottom of the fuel tank. Maybe that carb doesn't pump well enough at RPM & Load and needs freshening. Maybe a main seal is allowing a bit of air by at RPM and leaning things out a bit. Maybe the fuel supply line is partially plugged..bottom line is I wouldn't accept that those 82cc Homie's boil without a solvable problem.

Yep, I dont think its normal, as my other two have never done this.

The only thing I can think of is a seal leaking at high RPM & not at idle, as it idles fine.

Plug is right (CJ-6 champ) has a new fuel line & filter (filter is on the bottom)

after I put the carb kit in I started with both the H & L 1 turn open & it ran like a scalded ape like that.

Ill mess around with it tomorrow & see what happens. neighbor has some huge cottonwood i can sink it into.

 

[Ax-man]

I had the same problem with those Homelites when we using them, way back when. Make sure your gas cap is venting. This won't really solve the problem but will help, try not to screw the gas cap down to tight, but not so loose that fuel runs runs out. As the weather gets cooler this problem will go away.

Larry

 

[smcowboy1974]

I have a Homelite Super XlAO that does the same thing. Even if it's about 40 degrees fahrenheit out it still boils the fuel. My chainsaw buddy Marco Puts 1 qt. of Kerosene in with 2 gallons of regular 87 octane. His old mccullochs run a lot better, and even start fine on this mixture. The kerosene helps the saw to start better after being hot. It smokes a little at start up, but after the saw warms up you can't tell the difference. All old Homeys like this run hot. As long as the high jet is rich enough you should have no problems. CJ-6 is the right champion plug. It's probably white because your using Mobil racing 2t which burns cleaner than a whistle. Take care and have a happy labor day!

 

[weimedog]

I have been running Mobil One as well. Usually at 32:1 sometimes at 30:1. It does burn really clean. Remember you have to tune to your fuel mix. More oil volumn leans the mixture so you need to fatten things up a bit. I also used 100LL fairly often with my McCulloch Milling saw. Ran really cool (low temp) with that arraingment. I have been running 89 octane recently in my Homelites...100LL was 3.57 per gallon. (Been running my XL800 and XL-S 925 this last week a lot) Last week our fuel prices shot up so I will be going BACK to 100LL! Its CHEAPER than mid grade this morning! Go figure.

(I ran my XL-S 925 today with a 28inch bar in Ash and Hard Maple. Hard work for the saw on these 28inch dia logs.....no boiling after about 3 hours. Never boils. Great saw.)