149 misses

Dave R · #1 09-30-2013, 07:50 PM

I have a 149 that has been sitting for a year or so waiting for me to regain my interest in getting it running.

Here is what happens...It starts right up, idles fine, increase the speed a little and everything is still fine. Ease the lever forward and start around the yard and put a little pull on it and it starts to miss just like an engine out of time. I mean miss bad and shakes too. If I stop and reach down and readjust the high speed mixture setting on top the carb I can get it to smooth right out. Then everything is fine until the load changes again. If I run it slow and just make orbits around the yard it is fine. I even hauled a big load of wood today at just above idle and all is well.

I took the carb off this morning, soaked it about an hour blew it all out and put it back together, same result. Changed the fuel filter, blew the fuel line out, new spark plug, but still the miss under load when the governor calls for more fuel.

I think it has to do with the mixture that you set on top of the carb next to the throttle shaft. Adjusting that always smooths it out. I have put enough air through it from both ends to have blown most anything into the next county. And yes those four little holes in that adjustment valve are clear.

What I think happens when the governor calls for more fuel the engine is going lean, thus the missing, shaking and occasional backfire. So, a carb kit looks like it only have the float cutoff and some gaskets. I'm about to the point of just getting a different carb.

So, give me some ideas. Thanks for the help.
Dave in SW Missouri

_DX3_ · #2 09-30-2013, 08:07 PM

Check the throttle shaft and see if it has lateral movement. I could be pulling air thru there if it is worn. If it is, it's time to put in a shaft bushing. Also you can set the timing and it might also be time to do that. You will have to remove the starter/gen to see the timing hole in the flywheel shield. Also might be time to check and maybe replace the points and condenser especially if you plan on setting the timing.

Timing link:
http://www.onlycubcadets.net/forum/s...ead.php?t=4405

IACubCadet · #3 09-30-2013, 09:54 PM

I'd try a condenser. I had a similar problem with a 107 years ago. I would adjust the main jet and it would act like that fixed the problem, but it never really did. I would drive 50 feet wide open with no issues, and then it would miss and shake for a while, then run fine. A new condenser solved that problem real quick. Just my .02, might not even be worth the two cents, but there you go.

zippy1 · #4 09-30-2013, 11:16 PM

Quote:

Originally Posted by IACubCadet

I'd try a condenser. I had a similar problem with a 107 years ago. I would adjust the main jet and it would act like that fixed the problem, but it never really did. I would drive 50 feet wide open with no issues, and then it would miss and shake for a while, then run fine. A new condenser solved that problem real quick. Just my .02, might not even be worth the two cents, but there you go.

X-2

Yosemite Sam · #5 10-01-2013, 01:02 AM

Quote:

Originally Posted by Dave R

And yes those four little holes in that adjustment valve are clear.

Is the tube between the upper and lower holes clear?

I'm somewhat torn about this one... After setting, the carb could shellac up inside (along with the tank, fuel line and screen in the valve). I don't know that soaking for an hour will dissolve all the impurities that could contaminate the system. The tank should also be cleaned as well.

There is no mention of how the machine runs/performs at wot (this is where the engine should be running when in use anyway).

I agree with checking the throttle shaft for wear, probably should also check for a bad head gasket/warped head.

I also agree with cleaning/replacing the points and setting the timing. Even if you don't directly suspect a timing issue you can spend a half hour adjusting the timing properly and you can then rule that out as the problem and move along with confidence to something else.

Good luck.

98% of all carburetor problems are electrical.

Dave R · #6 10-01-2013, 01:28 PM

What a day. Tried everything, cleaned the tank, cleaned the lines, took the carb apart, put that all back, tried new coil to plug wire.

Did the Static timing, didn't run right, so I started adjusting the points a little at a time. Got it to where it ran seemingly ok. I ran it up and down my road a mile or more, ran out of gas had to walk home, get the gas can, walk back, started right up and home we came.

I believe the darn point setting was it all along. Took some years off my life. Beside it's warm here today and the mosquitoes are alive and well.

Thanks to every one for your help. This is a working Cadet. I haul wood in, pull the wood splitter, and in general it earns its keep.
Thanks again
Dave in SW Missouri

ACecil · #7 10-01-2013, 01:33 PM

Glad to hear, you got it figured out!

Dave R · #8 10-03-2013, 11:50 AM

I am happy to say I hope I got the 149 up and running ok. I worked it like a tank yesterday. Had a huge red oak that blew down a couple summers ago just north of my house in a heavily wooded area. I cut a road into it and cut it up into manageable pieces and threw a nylon strap around them and pulled them to my wood yard, a 100 yards or more away. The old girl never missed a beat, other than ran out of gas once, (about the same time I ran out too) It was apparently a points issue all along, but it took a while for me to get there.

This is a working 149, and believe me it worked!
Thanks for the help, and thanks for the old Cadets.
Dave in SW Missouri

ACecil · #9 10-03-2013, 11:54 AM

Quote:

Originally Posted by Dave R

I am happy to say I hope I got the 149 up and running ok. I worked it like a tank yesterday. Had a huge red oak that blew down a couple summers ago just north of my house in a heavily wooded area. I cut a road into it and cut it up into manageable pieces and threw a nylon strap around them and pulled them to my wood yard, a 100 yards or more away. The old girl never missed a beat, other than ran out of gas once, (about the same time I ran out too) It was apparently a points issue all along, but it took a while for me to get there.

This is a working 149, and believe me it worked!
Thanks for the help, and thanks for the old Cadets.
Dave in SW Missouri

Glad to hear the 149 is doing well for you!

kostendorf · #10 10-03-2013, 12:30 PM

Dave, Glad to see another Missourian. I'm from Troy Mo. and about those points, I need to change the rod that rides on the cam in my 1650 but as long as its running good I'll leave it alone. I had to set my points at .024 to be in time. But what I need to say is The static time method worked. When the s was in the window I was at .024. Did you have to widen or shorten the gap after you static timed it?