Can't start my Toro/Briggs 6.5 hp mower [Archive] - HobbyTalk

: Can't start my Toro/Briggs 6.5 hp mower

09-02-2010, 10:39 PM
I have a Toro 20065 mower bought in 2008 that won't start. Late last year (I'm in FL so we mow all year long) the mower started to surge on start but would soon level out, and then the primer bulb melted off. The gas was about 5 months old - probably older than I should have been using, but I've always bought 5 gal at a time and just kept using it - the new mower goes through less gas since I only have to fill half the tank to get through the whole yard. I replaced the primer bulb and switched to using 2 gal gas tanks, and wondered whether any other parts inside had been damaged.

Last Saturday the mower kept almost stalling out. The gas was only about 2 months old but I decided to go get fresh gas. I also stopped into Home Depot where they told me to use Mechanic In A Bottle in the gas. The instructions said to run the mower for 10 minutes but when I went to do it the next day, the mower wouldn't run for longer than 30 seconds at a time. I kept starting it back up again to get the cleaner into the engine as much as possible. The next day the mower would not start at all.

First I checked the fuel line. The fuel was definitely running to the carb (and also taught me that the tank has no fuel cut-off valve). I had some difficulty removing the carburetor and may have accidentally bent the governor wires above it a little. I was expecting the bowl to be all gummed up but it was quite clean, though the gasket was getting worn out. I cleaned it anyway and sprayed the carb down with cleaner, then put everything back together. It would still not start - if anything it sounded 'more dead' than it had previously. I also changed the spark plug, which made no difference. Shooting starter fluid into the spark plug chamber would let the engine start for one second before it would instantly die again.

I bought a carburetor overhaul kit and replaced the gaskets and the float valve pin gasket/seat, I shot carb cleaner through the nozzles to clean them out. I then put it back together and learned how fast it leaks when you forget to put the float valve pin in. :drunk: After putting everything back together properly this time, the engine was still the same - would not even try to start.

One thing I have yet to try is from a comment in a thread I found here that mentioned that the air filter / primer assembly may be warped, but I would think that even if there was a problem with it the engine would at least 'sort of' start up instead of being completely unresponsive. Is there any way to test if this is the problem before I go out and buy another one - the parts store is far away enough that I'd prefer to have at least some clue of what's really wrong with the mower. Someone else mentioned it might be the magneto. At a minimum $90 charge to work on the mower I may as well buy a used or even a cheap new mower and give the broken one to them than to actually pay for repairs - it needs a new starter cord too.

Thanks for any help you can give me.

09-03-2010, 04:12 AM
Did you clean the tiny holes in the bowl nut?

09-03-2010, 02:09 PM
I'll double check but I'm almost positive this one does not have that. It also does not have an adjustment screw.

09-03-2010, 03:22 PM
Yeah as previously stated I would check the passageways in the bowl nut, also inspect the intake tube which runs from the carburetor, under the engine shroud and bolts to the engine block. They are known to loosen up.

09-03-2010, 07:37 PM
Ran out of time to work on it this morning, only got as far as pulling the shroud and the flywheel bolt and cup to see if the key had sheared. It looked fine to me (though I didn't pull the wheel since I don't have a tool for it). Kind of worried about whether or not I got the bolt back on tight enough. It's pouring so I can't work outside (it's death to work in a garage here in South FL), will have to get up early to mow the lawn with a borrowed mower and hopefully have enough time leftover to inspect it more and get to the parts store if I need 'em (closes at noon). I always worry that the more I pull apart the more likely I won't be able to put it back together properly - the manual on Toro's website doesn't show actual assembly very well. I'd have less trouble pulling apart the $5k floor buffers we sell at work since the manuals show closeups of how every single tiny part goes together.

09-06-2010, 05:14 PM
Cleaned the carb again, the holes in the bowl nut were clear. This time I did hear the engine start for a brief moment, then back to dead as usual. I'm starting to think the entire carb is bad. Are there parts in the carburetor that can't be fixed? I'm thinking that when the bad gas melted the primer bulb off it may have weakened things inside the carb as well, which finally broke completely. The only plastic part other than gaskets that I could replace would be the bowl float, but I'm wondering whether I should just buy a whole new carb.

09-07-2010, 09:58 PM
Inside the carburetor, did you clean the main jet which runs up to the throat of the carburator?

09-08-2010, 10:43 AM
Finally gave up and brought it to work with me (some of our warehouse guys have experience with small engines, they've been trying to get me to bring it in all week but I didn't want to have 'em use up their lunch hour for it). Engine's seized. They think they might be able to unfreeze it. They can't figure out why. I change the oil, guess I don't change it well enough (siphon) or often enough (probably about every nine months - try to do it twice a year but I'll forget to keep on schedule). It just kind of bugs me that I've had lawn mowers that lasted 8 years with me taking much worse care of them and this one dies on me in 2. If they can't fix it I'll probably get one with a Honda engine instead of a Briggs.

Thanks for all your help guys.

09-08-2010, 07:42 PM
I find that a little odd, how the engine suddenly seized.. If it was still pulling over when you were working on it?

09-08-2010, 09:35 PM
Yeah. Maybe it was starting to freeze up and me continuing to force it to ignite with starter fluid finally broke it all the way? I just don't know enough about working on small engines - I'm a quick learner but I spent way too much time messing with it and getting nowhere so I let someone else mess with it.

Looking around at lawn mowers they all seem to be exactly the same, have the same engine and mostly the same frames, just different paint jobs and /maybe/ a different setup for the self-propel mechanism. Getting conflicting reports on whether to get Briggs ("you got a lemon - they're cheaper and usually work fine") vs Honda ("They have a timing belt so that's one more thing to break"). There's actually not much of a price difference - Lowes has Troy-Bilt Hondas for $300 and the B&S are $280. Also "Spend the extra money on rear wheel drive instead of Honda".

09-09-2010, 07:05 PM
Go to a dealer and buy a decent unit, dont go to the box chain stores. Snapper makes some really nice units and so do Honda. I would stay away from craftsman, MTD, the cheap Toro units, Murray and anything else they sell at Home Depot. Except the Honda's.

09-10-2010, 02:36 PM
If you go to a dealer you'll spend a lot more than $280 for a mower. I agree many of the mowers you find will either have a briggs or honda engine that you find at lowes or sears and these are the same engines you'll find on an expensive mower from a dealer. The only real advantage I can see with a Honda mower is the plastic deck. I've been working on junk mowers and fixing them up and selling craigslist for a while. All the "broken" mowers I get all seem to have one thing in common- poor user maintanence. If you leave wet grass on a steel mulching mower's deck guess what- it's gonna rust. If you store your mower outside all season long guess what- you're gonna get water in the gas and it won't start. I suppose what I'm trying to say is buy the craftsman special at sears for $299, chnage the oil, keep your air filter gas, and mower deck clean, store it in the garage or shed and your mower should last just as long as that pricey one you'll find at a mower shop.:thumbsup:

09-19-2010, 03:17 PM
The guys at work finally did manage to fix it this week, unfroze the engine. It still needed a new carb (they'd been testing it with the one from the mower at work and the parts to fix it were almost as much as getting the whole thing) on top of everything else. I spent a bit more than I wanted to but I feel better fixing it than throwing it out and buying another one.

We keep it outside but it's in its own mini-shed on a covered porch. I mow the lawn at least once a week here in FL even during winter so there isn't really time for it to get water in the gas. It doesn't really have any rust. I guess I need to do a better job making sure the oil is fully changed. Thanks for everyone's suggestions, but the fix was a little beyond my skill level.

Now to figure out why the pool pump motor is overheating and shutting off. If it's not one thing...