Mower engine - UPDATE

[awiecek]

Hi all...

Some of you may recall I needed help in diagnosing my parents' Toro mower engine. The thing would start, run about one or two seconds and then die. I checked the plug, even tried several new ones, gas float and so on... Well, this weekend I took the carb apart to clean it up. I didn't find anything out of the ordnary. The passages appeared clear and the main tube running from the gas bowl into the throttle body was clear as well.

I put the carb together, installed it in the engine and found the same effect. Prime the engine about 5 times, start the motor, motor would run for 1-2 seconds and die, it would not start again unless I primed it.

I measured the cylinder compression to be about 90 PSI.

Then I tried to choke the air intake by removing the air filter and jamming a piece of cloth to restrict the air intake. I started the motor. It ran very rough, so I slowly withdrew the cloth from the air intake. Had I pulled it out right away, the motor would die once again. After about 10-15 seconds, I was able to completely withdraw the air obstruction and the motor ran fine. Once warmed up, I could stop it and restart it without a problem.... but once cooled, I would have to go through the exact same routine of introducing a "manual choking system".

Hence the question.... do these motors have some sort of a choke, or am I missing something? Is there something obvious that could be causing my problem?

thanks Alex

[Oren]

Just my experience here. The carb on my power washer has tiny "inlet/jets" (not sure of the name) located in the carb throat.. The only way they can be cleaned/cleared is with a piece of stainless wire plucked from a wire brush. (Do_Not_Break_The_Wire)

Another thing to look at is if the float jet is damaged on the tip or is otherwise sticking.

I might even suggest you soak the carb in a cleaner (auto store kit) for a day and blow is out with compressed air.

Have adjusted the float with the a gauge?

-- Oren

"Well, it doesn't happen all the time, but when it happens, it happens constantly."

[Meat Plow]

No choke on a GTS engine. Common problem is the bowl supply tube (actually the bolt that holds the bowl on) gets gunked up on the bottom. Make sure the holes are clear. Same goes for the primer. I have a Personal Pace 6.5 hp electric start that I bought new 5 years ago. Let bad gas in it just one off season and the damn thing would not start. Addressed those two areas I described and it starts on the first crank after pushing the primer rapidly several times when cold otherwise no prime needed.

[awiecek]

Thanks for the reply

I'm pretty sure that's the same Toro my parents have. It's a 6.5 with an electric start and no need to push it as it will keep pace with you. Anyhoo... I checked, and cleaned the bolt, the supply tube from the bowl is clear as well. I'm just not sure about the other little channels in that carb (there are a couple of them there). But I will take the carb apart again and try to make sure those are clear. My parents kept the gas in it since last year. It ran ok about 3 weeks ago but then they tried to cut the grass the following week and it just wouldn't start.

[Meat Plow]

I've found that it's better to hit the primer maybe 10 times or so rapidly rather than the 3 times slowly that the sticker says. Get your parents some Sta-Bil additive and have them use it all season. I do it on everything and have snow blowers, trimmers, saws, chippers, blowers, mowers. I let the Toro sit this winter without doing a thing and it started right up thanks no doubt to that fuel stabilizer.

I'm sure you will figure it out.

[Noozer]

You HAVE put new gas in it, right?

: )

Just checking.

[Oren]

How close are these ("channels") to the primer bulb; presuming, inside the carb throat? They are "tiny", right? Once cleared from (shellac/clogs/etc.) your engine should run.

If you try a wire as I mentioned, don't break it off in there.

-- Oren

"Well, it doesn't happen all the time, but when it happens, it happens constantly."

[awiecek]

Ummmm.....welllll....... something I meant to do last week but neglected to. I guess I should try that as well.

:)

[awiecek]

I hope so.... thanks for the advice.

[awiecek]

I have just the wire for that. I'll see if I can get at it again tomorrow or sometime next week...

thanks

[Oren]

If one of these inlets ("channels") is near the choke butterfly/baffle in the throat clear it for air.

If one of these inlets ("channels") is near the primer bulb in the throat clear it for fuel.

-- Oren

..through the use of electrical or duct tape, achieve the configuration in the photo..

[HeyBub]

That's it, then. Gunk floating around in the old gas clogs that which you've cleaned.

[Oren]

Sticks the float, jets, seats..... something between a gasket sucking air - who knows?

Clean fuel was a great question.

-- Oren

..through the use of electrical or duct tape, achieve the configuration in the photo..

[Noozer]

Well, my mower ran great for about half the yard, then refused to run, like yours.

I dumped the fuel into a glass jar and there's about 1/2" of water sitting at the bottom of the jar, with about five inches of fuel floating on top.

Mower runs great now that I've got GOOD gas in it.

[DanG]

Several capsfull of injector cleaner in the fuel tank sure won't hurt anything. Several squirts of carburetor cleaner when starting won't hurt either.

[Oren]

I have a tee-shirt :-\\

Imagine that!

-- Oren

..through the use of electrical or duct tape, achieve the configuration in the photo..

[Shopdog]

Between the carb and the tank should be a gasket and a diaphragm membrane, Chances are that you need to replace the membrane Like your not getting the suction to pull the fuel from the tank into the carb, you can put the fuel in the carb by primer bulb and the engine runs, right? So your problem is that your not getting fuel from tank to carb. Nothings plugged youjust don't have the vaccum

Searcher

[Bob F]

I've got one with the same problem. I've just been pushing the primer every few seconds after starting untill it warms up enough to run right. I'll also try this and maybe other fixes suggested here and see what happens.

Bob

[Oren]

It really shouldn't be necessary to do this.

Given this engine needs intake, compression, power and exhaust.

Think air and fuel - without a primer bulb....

-- Oren

..through the use of electrical or duct tape, achieve the configuration in the photo..

[Bob F]

It shouldn't be necessary, but if I don't do it the engine dies, just as the O.P. described. What exactly are you trying to say?

Bob