mouse troubles and how to test carb behavior on K301, CC129
 

Hello Gang. Frustrating day here. I should have really cleaned out the 301 before today's attempted start bcz at both the front and rear of the engine mouse things happened. Much worse than previous years. I must try the dryer sheets method next winter...

After cleaning up the mouse, whose complete organ group was neatly separated from its elongated body, I proceeded to try to get the nest out of the flywheel area. This one was dense, and I got frustrated and tried to spin it out using the starter and an air compressor with a long air wand- stuck down almost touching the flywheel. No start. I finally got the nest completely out by hooking parts of it with a hooked gasket pick. I check spark- yes. I clean points. I change fuel filter and the very old hoses. I check the carb needle for flow through. No start. I notice that some head bolts are not very tight, so I open that up and give the mating surfaces a basic cleaning and put them back together with better torque. No start. Key then breaks off in ignition. Small screwdriver to the rescue.

This K301 ran fine when parked in November. So... the carb looks like an inexpensive non original one. Maybe I should change that after 5 years of use. Maybe it is not really sending fuel. Or maybe my spark is too small but it looks average to me. Maybe the points gap could be changed... Could the mouse nest and urine in the flwheel area have damaged something there? I "wants" to start, but wont even fire on spray. Thank you, helpful folks, for reading.

Compression? Sticking valve maybe?

While I had the head off, I spun the engine through its cycles. The valves rose and fell, were not loose and appeared okay to my amateur eye.

You have a starter/generator, no alternator under the flywheel, so there is nothing that could be damaged in there.
When you say you "checked the carb needle for flow though", what do you mean?
Did you have the carb bowl off? Was there a powdery residue or other crap in the bowl?

You say it won't fire "with spray"


If you squirt a little gas into the cylinder down the carb throat , will it fire?

I’m thinking stuck needle and seat in carb not allowing fuel to flow into the bowl. With fuel valve on crack the bolt loose on the bowl and see if any drips out.

You folks are very helpful. Thank you for saying that there is nothing delicate at the bottom of the flywheel area. I have not exposed it yet, and I would like to avoid that.

When I say no start "with spray", I am talking about some ether into the body of the carb. I am using an ether with lubricant, I think it is 50%. It wont even really "pop" for 1 or two spins. The only hint of combustion/explosion sounds like 1/3 of what it needs to spin up to speed.

When I say I checked the carb needle for "flow through", I mean I gently poked it with a nylon bristle from a parts cleaning brush, I sprayed it with carb cleaner, and then with my mouth I found I could easily blow through the length of the needle and found that both tiny holes were clear.

Lastly, the float bowl does have some gas going to it for sure because it flows out when I removed it. A few years ago the float valve gave me some trouble but then became functional again. I think I should try a new carb. I should also remove last years fuel, although it did have stabilizer in it.

My new fuel line route is a little longer than the previous one. Maybe I have violated some plumbing principal of gravity fed carbs, but I don't think so. If anyone can send me a link to a photo of proper fuel lines on a K301, CC129, that would be great. There seems to be very little room for the in-line filter. Maybe I should buy a smaller filter too.

I believe there is a compression release function on the 301, is it spinning fast enough to build compression? how is your battery? I had a starter/generator go out (slowly) and it would not start as it had no compression due to the slow speed of the starter. once I got a new starter and realized how fast it is supposed to crank it starts right up.

Did you squirt some actual gasoline in the carb throat (I like a hot dog mustard squeezer for this but you can dip some fuel line into a thing of gas then hold your thumb over the dry end ... put the wet end into the carb and release thumb)




This is a faster test than most ....

If it start and runs for 5-10 sec you can be sure it's a fuel issue (not compression release, valves, etc...)


...if it does then...


If you remove the fuel line from the carb end, does fuel run out?


If it does, it's a carb issue


These carbs are so simple, there's not much that can go wrong . If you CAREFULLY take the bowl off so as to not tear the gasket, if you clean the needle and seat and can blow from the seat to the gas inlet, then carefully reassemble, there's not a whole lot else that can go wrong.

success!! running!! phew.
 

Thanks everyone. Your comments and willingness to share helped me dive back in to the 129 today. As is often said- be methodical and check everything piece by piece.

I gave the somewhat drained battery some more charging time. Meanwhile I looked at that needle again and realized that it has maybe six holes in it. So I carefully cleared them and checked them. Then I ran the starter three times, about ten seconds each. I added more 50% ether spray (the kind with some lube in the mix) and FINALLY a few gentle bangs. Immediately a whole handful of moist debris and mouse bodies flew upwards out of the flywheel area. I will NOT be sharing pics of that. I truly believe that this hidden debris was probably slowing the crank speed to just below the rpm it needed.

After that, it was running like a champ, probably better than all of last year due to everything I tweaked. I drove out of the garage so distracted that I dragged the charger and extension cord with me.

So thank you, and now all is well. Time to use those dryer sheets or something. Mothballs did not work for me. I have included a few pics. (Yes, some parts are still off, including air cleaner, air shrouds, and exhaust supports.) And feel free to criticize my temporary fuel line. I think I need a smaller fuel filter.

The fuel line is not correct, should have no bends in it.

from the manual the 301 automatic compression release stops working at 650 rpm. so unless the engine spins at 650 you wont generate enough compression for the engine to start. The compression should be 110-120 psi and anything below 100psi warrants a "reconditioning" - I hate mice!

Cash- I think you were right about not enough speed to start- this makes more sense to me now. And yes, Minion, my line looks odd. Does anyone have a photo or a diagram of a well-run fuel line? Like I said, I think I need a smaller filter. And I am unsure of whether to route the line along the inside or the outside of the throttle cable linkages. Thanks again.

There should be all the filter you need in the tank now as part of the shut off valve.

I'd remove the tank and remove the valve w/the filter, clean and flush as may be needed, reinstall and ditch that extra filter that is mire or less redundant not to mention in the way.

Clean and install a new kit in the carb along with it's new valve seat and valve, readjust and be done with it.

When storing the tractor for long periods of time, merely shut off the fuel and run it until it quits.

I do this every fall for any that I will not be using until spring and they always fire right up come spring.

Thanks again everyone. The engine is running very well now. I eliminated the large fuel filter and replaced it with one of those very small B&S reg filters. They are smaller than an Oreo cookie. I don't want to mess with the tank and petcock filter this season- maybe next. The smaller fuel filter allowed the fuel line to run more directly.

The practice of running a carb bowl until empty was mentioned. I do this in our portable generator, but I guess I use the 129 to haul winter runs of firewood sometimes, so that bowl never gets drained.

I shut off the petcock on my machines every time I park them for the day. I hate being ready to get to work and finding my fuel has run through the carb and filled the block. I've had to do more oil changes on my machines over the years than I care to admit because of that, so I shut that thing and let it run out of fuel to shut itself off every time.

Mouse troubles
 

One other option would be to raise the front of the tractor so the carb is higher than the tank. Try parking it on a slope to see if this works until you figure out what is really the problem.
I replaced the carb on my 1450 and that solved a problem similar to yours. I’m guessing it was the float that was giving me the trouble. :bigthink:

All good now- running great. I do appreciate everyone's advice. It was either the mouse nests slowing down the flywheel, or maybe a plugged fuel filter. It now has no mouse nests, and a very small B and S fuel filter- I know, some folks don't use aux fuel filters.

Regarding fuel in an engine- I have never has fuel trickle down past the carb while the tractor sat. That would be a pain. And yes, I keep the petcock closed, but I do not often run the float bowl dry. It's a cheaply built carb, but its been okay for five years of rugged use.