Lawnmower hard starting

[wallyuwl]

Lawnmower, a three year old Toro with the B&S 190cc engine, is starting hard and has for a year or so. Takes a dozen pulls or so to start. Runs rough to start but is fine once it warms up. New plug and filter every spring, as well as an oil change every year with synthetic 5W30 (usually Synpower but this time used some of my FAR G-oil).

I have been using 87 octane, 10% ethanol since new (supposed to be OK according to the manual). I used this because I was unaware of anywhere to get ethanol free fuel here. Just bought a Stihl leaf blower and the sales guy told me of THE one place in town that sells it. So now I'm going to switch the lawnmower to no ethanol fuel as well.

The question: I think the carb is probably gummed a bit from the three years of ethanol fuel. Anything I can put in the gas to clean it up?

 

[DemoFly]

I put seafoam and techron through our mower all the time.

Mix it appropriately and go about your normal business.

I wouldn't mix up a 2-stroke batch with it. I would just use a good synthetic non-crude 2 stroke mix and not think twice about ethanol.

I find Husqvarna mix at 50:1 or Amsoil at 90:1 is hard to beat for value/performance.

 

[ironman_gq]

Clean the carb, best way is to remove it and blow out the jets and passages with carb cleaner or brake clean. I've had good luck just removing the fuel bowl and blowing out the main jet and cleaning the bowl out.

If you want to try a cleaner first, I would just run some seafoam through it, I've used up to a half can in a lawnmower and for soft deposits it does an excellent job. B12 chemtool is another one that works well (easy to find at wal-mart)

 

[Quest]

Is it one of those B&S flathead engine?

Have you check the flywheel key to see if it's shifted/sheared?

Q.

 

[PhilsSmallEngine]

Does it have a primer bulb on it or is it one of those [censored] autochoke carbs? If it's an autochoke, remove it and buy a primer based carb and the filter plate with the primer bulb. Best $35 you'll spend.

 

[Merkava_4]

Post the engine numbers.

 

[joemo]

I took jet out of carb and soaked it in seafoam 20 minutes it looks new and runs like new.

 

[Nyati]

I use nonethonal gas in all my OPE. Seems to help. They all start right up.

 

[Kestas]

I second Quest's recommendation to check for a partially sheared flywheel key.

 

[bubbatime]

Check the flywheel key first. If that is OK, then replace the carb. They are only $20-25. I've had 100% good luck with the aftermarket Oregon branded carbs as well as the slightly more expensive OE Briggs carbs. Both carbs will be made in China at likely the same plant.

Also, if this is an auto choke engine and not a primer bulb engine, than you need to check that it is functioning properly. They freeze up, especially if the mower is left outside. It will be extremely hard to start if the choke linkage is stuck in the open position.

 

[Merkava_4]

9 times out of 10 the carburetor needs cleaning. They are very sensitive to fuel contamination.

Most don't understand the importance of keeping the fuel clean.

 

[wallyuwl]

It is a Toro model 20333 with the 190cc B&S engine, autochoke. I will try cleaning the jet and bowl and go from there. I'll run some Techron through it probably too. If that doesn't help then I'll look at the flywheel key (I don't have the tool for that). I am pretty mechanical on cars for a DIYer but have never worked on small engines at all before except for oil, gas, plugs, and air filters.

I'm not a big fan of the autochoke engine. Where would I go to get a carb that would work with this engine that has the primer bulb and choke?

I looked and couldn't find a model number for the engine, just serial number and manufacture date.

 

[Merkava_4]

Originally Posted By: wallyuwl
I looked and couldn't find a model number for the engine, just serial number and manufacture date.


The numbers are either stamped on the blower housing or on a curved heat shield around the cylinder. For Example: 10M902 0489 E2

 

[threeputtpar]

I just serviced my B&S Intek 6.75 carb for hard starting when hot issues, and when I pulled the bowl off one of the welch plugs was at the bottom of the bowl. That was a surprise.

I'm guessing that the missing plug was allowing too much air in and when hot it would have a hard time starting. But the thing ran just fine after it started, and it started just fine when cold. We'll see if it fixes the problem, and the grass is still brown here.

 

[bubbatime]

Originally Posted By: wallyuwl
If that doesn't help then I'll look at the flywheel key (I don't have the tool for that)


No special tools needed to inspect the flywheel key other than a Phillips screwdriver and a socket set. You don't have to remove the flywheel to check it.

Here is a YouTube video showing how to dissemble the top half of your engine to get to the flywheel. Very simple two minute process.
https://www.youtube.com/watch?v=n4aFXHwxuhs

How to remove/rebuild/or replace the carb in this video:
https://www.youtube.com/watch?v=nudnwDKtz9w

 

[Merkava_4]

Still no engine numbers? How am I supposed to fix your mower without engine numbers?

 

[wallyuwl]

I put some carb cleaner into the air intake, and also cleaned the jets and bowl. Apparently didn't put the bowl screw back on tight enough because it leaked, so I cleaned it again and put it back on tighter. Doesn't seem to be leaking now and the engine is running much better. Put some Seafoam in the gas and put the E10 gas from the gas can into my car and filled the gas can up with no ethanol fuel (made a special trip across town) for going forward.

The engine number is: 128T02-3256-B1 (pretty sure that is correct)

Quick question: is the bowl/jets screw supposed to have a gasket or washer? Mine doesn't, just a small ridge that is part of the screw. But I'm not sure if it might have slipped off when I took it off the first time.

 

[wallyuwl]

Did some research and looks like there is supposed to be a washer with the jet screw. It isn't leaking right now, but I ordered a new screw (with washer) and bowl from repairclinic.com and will replace both when they arrive.

 

[bubbatime]

Originally Posted By: wallyuwl
It isn't leaking right now, but I ordered a new screw (with washer) and bowl from repairclinic.com and will replace both when they arrive.


SIGH. You could have ordered an entire brand new carburetor for about the same cost.

 

[bubbatime]

Your engine uses a Briggs and Stratton 799866 carburetor which is $25 delivered from Amazon for an OEM Briggs carb.

http://www.amazon.com/Briggs-Stratton-79...s=799866+briggs

You can spend hours chasing gremlins on an engine and trying to get it to run right. Spend 30 minutes rebuilding it, put it back on the engine, carb leaks, take it off, rebuild it again. Engine still doesn't run right. All that to save $5, when you should have just replaced the entire thing to begin with. You don't rebuild $25 carburetors, YOU REPLACE THEM.

Or if you prefer to bypass the auto choke altogether, you will need this primer carb and a Briggs 694395 primer bulb. Just add the primer bulb to your current air cleaner base after popping off the plastic primer cover.
http://www.ebay.com/itm/like/201066103567?lpid=82&chn=ps