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Toro 22" recycler model 20017 sn# 250066250
got it free on CL
not used in 2 years
bowl and plug/holes clear
fresh gas
only starts with shot of gas into carb whether hot or cold
once started will run without issue
I see eBay complete Tecumseh compatible 640350 carbs for ~$11
anything I can check before throwing my wallet at it?

Sounds like a carb issue or maybe compression since ether is more flammable than gasoline. Retorque the head and adjust the valves. Make sure the spark plug is clean and gapped properly.

Sorry I misstated when I said "Starter fluid" but now changed the title to gas.
I actually was just squirting gasoline into carb. Runs until I shut it off and then won't restart hot or cold without gas shot into carb.

Either the idle circuit is blocked, the priming / chokeing system is not working or there is a minor air leak between the mainjet venturi & the inlet valve
I am not familiar with your engine
If it has a choke make sure it closes fully when chokes. if not move the control cable .
Remove the carb & clean all of the internal passages
Saturate the regions from the top of the throttle butterfly back to the cylinder with WD 40 liquid and see if the mower blows a lot of white smoke as the w40 gets sucked in

OK thanks. will look into your suggestions.
Does the fact that the same problem exists whether the engine is hot or cold compel or eliminate any of your suggestions?

No but makes a clogged carb No1 on the hit list, unless there are other symptoms you are hiding from us till the final episode so no one can work out who the murderer is .

If it runs fine once started with a shot of gas straight into carb, but won't restart even while hot, where might the clog likely be?
I'll remove the carb later today and put it through rigorous questioning.
Or order a replacement for $11...

First, as I’ve said before, I’ve never trusted aftermarket carbs from Amazon or fleabay. Most times they won‘t solve the problem because they are not the exact one for your engine, just one for multiple engines. I suspect your problem on the original carb is an improperly set float height. I would clean the original carb again and then replace the float needle and seat with part #631021. After doing so set the float level slightly rich, meaning the side opposite the float pin slightly lower.

I set mine a touch leaner on the float. Slows down the carbon buildup in the cylinder/valves.

Setting the float on the lean side will make for harder starting. Been sett it my way for the last 15 years and customers love the easier starting. I’ve never had a problem with any carbon buildup, as long as I don’t go too rich.

my Toro (2006) has always been hard starting since new until i changed how I started it. Prime it with the bulb if you have one the number of primes marked on the unit. Pull the rope slowly until you feel resistance then pull hard. If the resistance is too late in the pull, leave it there, let the rope in and then pull hard. Whereas it might take 10 tries before, now it starts on the first pull each time.

OK got it. I will set it richer AND leaner.

Rivets said:

Setting the float on the lean side will make for harder starting. Been sett it my way for the last 15 years and customers love the easier starting. I’ve never had a problem with any carbon buildup, as long as I don’t go too rich.

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You are mostly a fixer, not a user like me. Richer will start easier, agreed. Even carbs with flat float settings will over time carbon up the cylinder. Think most engine manuals say like every 5 years, pull head and clean valves.

juicer said:

OK got it. I will set it richer AND leaner.

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Set the float flat or level with carb body. Get your choke working proper.

“ Think most engine manuals say like every 5 years, pull head and clean valves.” This is something I’ve never seen or heard. Personally I wouldn’t do this on my own equipment or charge a customer for unless there is some other reason to pull the head.

Unless the engine has been flooding or the rings are bad I am yet to find a mower engine that needs a decoke apart from 2 strokes and they get cleaned out with a water pistol .

This carb is such a pain to remove. Will work on it in a day or so. Appreciate all the suggestions.
Hold my ankles, I'm going in.

Thanks for the suggestions. 2 weeks recovering from bulging disc in back. Ordered ebay carb Tecumseh 640303 for ~$8 slapped it on and starts right up.
Will get down and dirty when the back is more betterer and I have time to clean the original.
I picked this mower up free on CL so I am not familiar with its normal running sound. Engine seems to be running at high rpm according to my tachometer ear.
Is there a preferred rpm for this engine?
Just adjust it down with idle screw and play this fiddle by ear?

Most Tecumseh engines should be set at 3200-3400 RPMs. This engine has a fixed speed setup, so adjustments are made by adjusting the governor control. Most ears are not calibrated close enough to do this.

Just tore into the old, genuine carb and removed the emulsion tube. The two o rings are shot.
That might 'splain the issue.
eBay has the 2 o rings shipped for about half the price of what I paid for the whole replacement carb.
Is there a spec on those o rings so i can buy locally or source from my Horror Freight collection?

Rivets said:

“ Think most engine manuals say like every 5 years, pull head and clean valves.” This is something I’ve never seen or heard. Personally I wouldn’t do this on my own equipment or charge a customer for unless there is some other reason to pull the head.

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Not for nothing. I looked at 3 of my push mower engine manuals. One a Briggs, one a Kawasaki and the other the gutless Honda GXV160. They all say at X amount of time, clean the combustion chamber....

Briggs manual


Kawasaki manual



Honda GXV-160 engine manual

Here's a Kohler engine manual I just grabbed off the internet. Every 100 hours have the combustion chamber decarbonized.

This is from my king shiz nit Wisconsin Robin EY20V or WI-185 engine manual.

Ok, I’ll concede that it’s being posted in owners manuals. That’s what they say in the manuals to CYA. I guess you’ll tell me that a majority of home owners would even think about doing this Or know what it means. I’ll still stick to my statement, “NO NEED TO DO THIS UNLESS YOU SUSPECT OTHER PROBLEMS “.

it is just my suspicion but almost all of my power equipment heads loosen up after many hours. It probably is less a liability for the manufacturer to say "clean combustion deposits" than say "retorque the heads", or "replace the head gasket." The two latter would sound like a design problem where cleaning carbon deposits would be a use issue. GM used to have their mechanics dribble water into the carb while the engine was hot and running so it blew quite a bit of the carbon off.

I have no idea about the need to decarbonise .
I have a feeling that it is added for historical reasons rather than actual necessity
With modern lean burn engines I never see appreciable carbon build up and on old side bangers there is no need unless the carbon is actually hitting the head .
The engine makers tell you to change plugs & oil filters at very short intervals where as in practice I would be lucky to change a plug at anything less than 500 hours, in fact some of the commercial customers with several thousand hours are still running the original plugs
The only time I decarbonize is when I do a head gasket or stake a valve guide.
For the past year I have been using my 1943 500cc side valve motorcycle
The makers recommended monthly decarbonizing when used daily, this bike has not been touched for 5 years
A piston builds up a carbon cover on the piston which is very beneficial to the piston
ON high performance engines, with squish bands of 0.020" then 0.005" of carbon can be a problem but in a vertical shaft mower engine it is akin to playing with yourself .

Chunks of carbon can break away, get into the bore, piston and ring area and gouge the crap out of these mostly aluminum bores. Yes some are cast iron lined. When that happens we get deep scratches which lead to oil burning. No secret where this leads.

Guess I'm the only one that buys/has old push mowers. Every one I've pulled the head on has plenty of carbon to make a sandwich out of. Huge chunks on the backside of the valves......

Rivets said:

Ok, I’ll concede that it’s being posted in owners manuals. That’s what they say in the manuals to CYA. I guess you’ll tell me that a majority of home owners would even think about doing this Or know what it means. I’ll still stick to my statement, “NO NEED TO DO THIS UNLESS YOU SUSPECT OTHER PROBLEMS “.

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I'm a home owner. I follow what's inside these engine manuals. Why? These people made these engines and know what and how to keep them alive.

Shop mechanics would never do this, I agree. Why? People want the cheapest repair possible and will not pay for something they've never heard about. Most people have been programmed with spark plug and air filter only in their brain. Anything past this and you guys get a ton of questions.

Some people run plugged up air filters and never change the oil. To each his own I guess.

In viewing a few videos on rebuilding carbs it is reported that the o rings and gaskets are susceptible to degradation from carb cleaner.
Wonder if the o rings on my main tube were affected by previous use of carb cleaners or starting fluids? That tube doesn't move/abrade so I can't see what else would cause failure.
Does ethanol containing gas cause the same issue?