149 Rebuild

[Vrobert]

My 149 has a similar story. My K321 engine serial number begins with a 16 indicating a 1986 replacement, while your engine was replaced in 1985. You will find this explained in the K321 service manual available here in the tech section.

Did yours also come with the fixed main-jet Walbro carb? Mine had a worn throttle shaft, so I bought a china replacement carb. It works OK after some tweaks and it was only $15. I also have a 149 thread here: https://www.onlycubcadets.net/forum/...ad.php?t=55868

[Aircomet]

Thanks for the information on the year the engine was replaced. This engine actually has an adjustable main jet walbro carb like most of the older ones. I’m hoping I can get it dialed in pretty good. I’ve had really good luck with these carbs so I think it will be fine. I have a few of the China knock offs on other tractors as well as the original ones were badly worn. They work okay; but, they all leak when setting so I have to shut the fuel off. They also can be difficult to get perfectly dialed in and don’t seem to start well in the cold like the original carbs did. I almost wonder if it is a jetting issue in them or just a poor casting. But, they get the job done.

[Aircomet]

Made some progress on the 149 this afternoon. Thanks to the generosity of another member here I was able to get ahold of the correct hydro control shaft and lever to replace mine. I got those installed on the tractor but I forgot to order the plastic friction bushing for it yet. But, for now it is tightened up enough to use. Then I painted and installed my new drive shaft and couplers from Jeff with new rag joints. I also bolted back on the seat pan and got my new seat mounted and new choke cable installed. So hopefully tomorrow I can heave the motor back in and button up the front end. Then, I should be able to attempt a test drive.

Sorry no pictures yet as it was well after dark when I was done putting tools and parts away for the night.

[Aircomet]

Well, I got the engine installed today and everything buttoned up nicely. Worst part was getting those front motor mounting bolts in. But I got it. I checked everything over once more and attempted the first start. It actually fired right up and after some carb adjustments it runs really well. Pto clutch works as it should as well as the hydraulic lift.

I took it for its first test drive and the hydro seems strong on it. But I definitely need to get that plastic bushing installed on the hydro lever as it is very tricky to hold the lever stable without any dampening right now. Now here is the bad news.

First up the my brand new cooling fan for the hydro has become a 10 piece design again. I believe a stick got up in it on the ride. Second, the hydro seems slower than my 147 does. It is plenty strong uphill and maintains speed fine but seems like it is a few mph slower than I’m used to. I was wondering if this could be intentional by IH since it is newer than my 147 or if I need to do some linkage adjustments?

Finally, the motor has a bad knock coming from it. It sounds very much like rod knock and I’ve eliminated the hood, pto, grill and other external parts. Only thing I haven’t checked is the muffler to see if a baffle is broken out. Could it be the balance gears causing this knock? I guess either way I am destined to pull this motor out again and tear it apart. It smokes anyways so I will probably go ahead and hone the cylinder and buy a rebuild kit.

[Aircomet]

I was just thinking that when I go to effort of removing the engine again I will probably remove the balance gears all together. I know many people do so and was wondering if anyone knows how big of a difference it makes on vibration? I just don’t like the idea of them deciding to do remodeling on my crank case and install a new window. I know not all engines had them anyways. But, if they run like a paint shaker without them then I’ll keep and replace them if bad.

[finsruskw]

your knock may be camshaft end play.

[Vrobert]

I've been getting some seat time on my 149, pulling the lawn sweeper around. I have noticed a rattle or knock that has me a little worried. It happens from mid to full throttle. It doesn't smoke so I'm hoping it's nothing serious.

Is there a foolproof way to diagnose this?

Aircomet, what town are you in? I'm near Annapolis.

[Aircomet]

I am near Sharpsburg Maryland.

What is the distinguishing characteristic of camshaft endplay knock? I noticed it doesn’t seem to be load dependentat all. It actually quiets up sometimes going uphill. It seems to be a midrange and high rpm most noticeable. Idle it is quiet. That’s why I am questioning rod knock myself as usual they will really hammer under load. Also it doesn’t knock every time it fires. It stops for a few revolutions and then knocks.

[Aircomet]

Also, is it a common issue for these newer style cam-cover dipsticks to be pushed out of the dipstick tubes by crank case pressure and start blowing oil out? I had to put a small spring on it to hold it in. But it doesn’t fit tight at all. O ring on it looks okay but might be worn. My buddy’s 169 has the same issue.

[Vrobert]

Originally Posted by Aircomet

Also, is it a common issue for these newer style cam-cover dipsticks to be pushed out of the dipstick tubes by crank case pressure and start blowing oil out? I had to put a small spring on it to hold it in. But it doesn’t fit tight at all. O ring on it looks okay but might be worn. My buddy’s 169 has the same issue.

If the vent isn't clogged is must need new rings. My Oring is good and tight, so try that first.

As for my knocking sound, I remember that the engine driveshaft coupler has a long notch worn in it. Could that be it? I'll remove the driveshaft and listen again. If the coupler is steel, I'll put some copper in the hole and try filling in the grove with my mig. While I'm at it I'll weld the broken heat shield.

I think our machines might be twins!