Cub 149

cmsedore · Nov 8, 2002

My brother recently acquired a cub cadet 149. It is in reasonable condition, has a mower deck and snowthrower.

The problem is it won't start. The past owner used it regularly (he passed away without anyone else knowing the secret to getting it to run). Here's what I know:

It has spark, pretty good spark actually.

It gets gas (plug gets wet after trying to start).

The starter (starter/generator combo) seems weak--it has trouble turning it through the compression stroke. It seems to have a bit of torque (I can't stop it by holding a wrench against it when the belt is off). We're having the starter rebuilt.

I put a new plug in. It fires on almost every rotation, but it blows back through the carb each time (one time creating a nice little fire

. I'm a little suspicious that the timing is off and it is firing far enough before TDC that it is pushing the piston 'backwards'/blowing back out the intake valve, but I don't see how to adjust that (and I'm not sure it is the problem anyway).

I've tried a little starter fluid and various options with the choke and throttle. Any suggestions would be greatly appreciated.

-Chris

Justaplain · Nov 8, 2002

Go to www.perr.com/forum. There are a lot of ggod mechs on there. bcs

rdln · Nov 8, 2002

The new rebuilt starter should do the trick, did with my 100.

cup149 · Nov 8, 2002

I bought a 149 a few years ago and it took me some time to learn the starting tricks. The timing could be off, or the auto compression release might not be working. But let's assume for now that they are correct. You are on the right track with the starting fluid. You note that it turns slowly through the compression stroke. On mine, this is can be a clue that it is not getting enough fuel to fire up. I will give it a big spray of gumout (more convienient than trying to spray gasoline) in the carb throat. Put the air cleaner back on because it acts as a flame arrestor. Then in cooler weather I hook it up to the 50 amp charger so it has enough current to spin fast enough. Full choke and turn the switch. After one or two slow revolutions it will turn over quite fast and puff brown smoke out the exhaust. Keep it turning over if it continues to turn over quickly. But if it goes back to just barely making it over the compression stroke, you need to stop and spray more flammable substance down the carburator. As long as it is turning over quickly it should start running on it's own and you may need to push in on the choke just a little once it's putting. Well, that's how mine has to be started. Some guys claim to get these engines to start in one revolution. Good Luck.

cmsedore · Nov 9, 2002

That's encouraging--thanks.

cmsedore · Nov 9, 2002

Thanks for the great info.

Can you point me to where I should look to check out the compression release? Does it blow back through the carb? (thus explaining the vent of gasses when firing...) I wondered if it had such a feature, but have not seen anything obvious (to me, anyway) while working on it.

We've been jumping it with a 50A charger/200A starter device, with some improvement. It just feels like three _quick_ turns and it would start right up--frustrating and has me wishing it had a recoil.

You got it right on the flame arrestor /w3tcompact/icons/smile.gif.

-Chris

cup149 · Nov 9, 2002

The compression relief opens the exhaust valve during part of the compression stroke. The file attached shows checking it after removing the head, but you should be able to take off the breather/tappet cover and see the exhaust tappet lift .030-.040. Setting the points at .020, gets you in the ballpark for ignition timing, but if you have a timing light, use that for final tweeking. The guys in the forum at www.ihcubcadet.com are the best bet for information.