122 only running sort of great - Page 3

Jbo_c · #21 08-26-2018, 05:54 PM

Strange that it’s not ‘supposed’ to have a pump. That one has every appearance of being original. I’ll run the gas straight from tank to the carb and see what happens.

Will get a sediment bowl enroute. In the mean time, I picked up a paper flow-through filter to use until the sediment bowl arrives.

Is there general agreement that this sounds like a fuel delivery issue? Or is that just a good place to start? I have a new coil, condenser, and(maybe) points that I plan to install, but I don’t really think any of them are the problem.

Thanks for the help. About to go change the fuel delivery and finish mowing. Will report back.

Jbo

Alvy · #22 08-26-2018, 06:44 PM

Quote:

Originally Posted by Jbo_c

Strange that it’s not ‘supposed’ to have a pump. That one has every appearance of being original. I’ll run the gas straight from tank to the carb and see what happens.

Will get a sediment bowl enroute. In the mean time, I picked up a paper flow-through filter to use until the sediment bowl arrives.

Is there general agreement that this sounds like a fuel delivery issue? Or is that just a good place to start? I have a new coil, condenser, and(maybe) points that I plan to install, but I don’t really think any of them are the problem.

Thanks for the help. About to go change the fuel delivery and finish mowing. Will report back.

Jbo

The provision for the fuel pump is there but should have a block off plate. Your model is gravity fed and uses a sediment bowl. The sediment bowl has a screen on the top that filters the outgoing fuel to the carb. It works fine that way but an extra filtering measure of an inline gravity flow filter in between it and the carb is fine too. If your pump is weak that could be the issue because it’s lower than the carb and has to pump the fuel up. It still does sound like a fuel delivery issue and also it’s a good idea to static time the engine if you put points in.

https://www.onlycubcadets.net/forum/...ad.php?t=33461

J-Mech · #23 08-26-2018, 06:45 PM

DO NOT put a paper filter on it if you gravity feed it. It won’t flow enough fuel through it. The pancake filter is better.

Alvy · #24 08-26-2018, 06:48 PM

Quote:

Originally Posted by J-Mech

DO NOT put a paper filter on it if you gravity feed it. It won’t flow enough fuel through it. The pancake filter is better.

I run one on all of mine with no issues.

J-Mech · #25 08-26-2018, 07:03 PM

Quote:

Originally Posted by Alvy

I run one on all of mine with no issues.

You must be lucky.

I spent a week when I worked at IH trying to figure out why a gravity fed Cub would die before the tank went dry. It was the paper filter. When the tank got low, not enough weight to push the gas through. Maybe you keep your tank full, maybe you have a low micron filter. I don't know..... But I've changed out a lot (and suggested it on here several times) since finding out the issue with that one long ago, and it always fixes it. I strongly suggest against it.

DeltaCub · #26 08-26-2018, 07:08 PM

Quote:

Originally Posted by J-Mech

You must be lucky.

I spent a week when I worked at IH trying to figure out why a gravity fed Cub would die before the tank went dry. It was the paper filter. When the tank got low, not enough weight to push the gas through. Maybe you keep your tank full, maybe you have a low micron filter. I don't know..... But I've changed out a lot (and suggested it on here several times) since finding out the issue with that one long ago, and it always fixes it. I strongly suggest against it.

Eons ago, I had a similar experience on a damned old Simplicity...two days. Put the fuel line back to the factory design and it ran fine.

J-Mech · #27 08-26-2018, 07:16 PM

Quote:

Originally Posted by DeltaCub

Eons ago, I had a similar experience on a damned old Simplicity...two days. Put the fuel line back to the factory design and it ran fine.

It came in for several things, that being one. I did all the work, went and mowed for 20 or 30 min and it was fine. Sent it home. Came back with the same complaint, "Dies after mowing a while.". Well, I went and mowed with it and it ran fine. Sent it back. Came back.... this went on for a while before I just went out and mowed with it until it quit. Problem was, when I got down to about 1/4 tank of fuel, I would go fill up. It wasn't until I tried to run it out of gas that I figured it out. Just below 1/4 tank, it would quit. My mistake was adding gas.

Jbo_c · #28 08-26-2018, 07:18 PM

OK. Finished my mowing without the fuel pump. Ran fine, but the same issue. I did use the paper filter, but maybe J-mech’s point is correct and that’s what caused it to keep having the issue. On the other hand, I was able to look at the filter when the issue was happening and could see that there was no fuel in the filter. Ergo, I’m thinking the fuel tank outflow must be clogged. That’s easy enough to verify and clean. That’ll be my next step. I was able to stumble through getting the mowing done that I needed done. Sadly, I’m heading out on vacation next week so I won’t get to report back right away.

Incidentally, I took a closer look while drinking with the fuel pump and it’s a light blue instead of Cadet yellow, so I guess somebody added it from another machine at some point.

Thanks for all the help so far. I’ll update when I get back and drain/clean the tank.

Jbo

cooperino · #29 08-26-2018, 07:18 PM

Quote:

Originally Posted by J-Mech

You must be lucky.

I spent a week when I worked at IH trying to figure out why a gravity fed Cub would die before the tank went dry. It was the paper filter. When the tank got low, not enough weight to push the gas through. Maybe you keep your tank full, maybe you have a low micron filter. I don't know..... But I've changed out a lot (and suggested it on here several times) since finding out the issue with that one long ago, and it always fixes it. I strongly suggest against it.

Yup.. I had same exact thing happen. Soon as I got to half tank and extra pressure went away it would starve for fuel and run like crap. Installed bowl, took out filter. Never happened again.

Edit. This was on my 126. The PO had the paper filter in there... I made the mistake of putting same style filter on before I realized it should have a bowl.

Alvy · #30 08-26-2018, 07:33 PM

Quote:

Originally Posted by J-Mech

You must be lucky.

Well, maybe. Or maybe it’s because I’m at sea level and that has something to do with it.

I run them all the way down to the nub with no issues. Maybe there is something to it I don’t know. I just figure the micron rating of the sediment bowl sometimes doesn’t keep all the poo poo out and I can see the gas flow in the clear paper ones. My rusty tanks don’t help either and the paper ones seem to filter it all out so I don’t get stuck needle osis. I see how your explanation can happen though.

Remember too I have that rare tropical grass that everyone gets told they can’t mow in the “transport” position but all of mine are set at that height to mow with.