Intermittent poor running on my 129

[three4rd]

Some of you guys have been through the (now closed) threads on all this, and I really didn't expect to come back here again after what took place with some of my posts, but I thought I should check back in for any further advice.

The debate rages on as to whether I should keep my 129 or buy a new XT3 model (which is probably the best model out there at this point?). As I believe I mentioned awhile back, my brother took the cub down to his shop to work on it. The one thing they discovered almost immediately is that the carb was shot, and so bought a new one and put it in. Along with a few other non-engine-related issues that they found and repaired, they then said it seemed to be running great. In fact, my brother felt so confident about it that he was getting ready to load it on his trailer to bring back to me and then just like that when he started it to drive it on the trailer it was running as poorly as it did this summer. His description matches exactly what I was seeing a few months ago - that it simply has no power. So I suspect it may well be a case of his simply not having had it long enough to see the pattern that has emerged over the past year or so - that of it running fine one moment and not fine the next. Points are new, properly gapped, and basically all new electrical components...all this stuff was described in my previous threads so I won't go back into it all.

At this point, he'd like to disconnect the ACR system and get a compression reading on it, as well as possibly check the valves. The problem is, they really don't have much time at the present or foreseeable future to do anymore with the cub.

We've discussed the option of getting a remanufactured short block (or would it be a long block?) from this Kustom company that was recommended to me here. A question that remains in my mind at least, not being a mechanic, is - what other components are there besides what I'd get with a rebuilt engine that might be causing running problems? If components extraneous to what I'd get from Kustom are causing the problem and simply get bolted back on to the new block, then won't the same sort of problems still be there? If putting in a rebuilt engine might possibly still not improve the running condition all that much due to some other weird problem that is taking place, then I guess it'd be better to buy a new tractor. I've been looking at the top-of-the-line cubs - the XT3 series. All I can say is, for $4-5k, I would hope that something like that should last longer than 3 years, which is about the lifespan that everyone is telling me new machines have. IF I could be guaranteed that putting the rebuilt engine in my 129 would basically restore it to running condition, I'd say let's go for it. I have little interest in buying a new tractor simply for the sake of buying a new tractor. This is why I still drive a '95 Riviera that is on its third engine I suppose. The guy at Kustom indicated that they stopped repairing tractors (even fairly new ones) cause they got tired of people bringing them in frustrated that their 3-year old tractors already stopped working, along with complaining to the shop about it.

Any further thoughts on this situation please let me know, as I really am not certain which way I want to go with this. Besides the puzzling intermittent poor running, I also have the leak in the transmission that has been there for years - hasn't really gotten any worse so I just keep adding fluid. And, it goes through right front wheel bearings. The oil pan drain bolt has issues too - I try not to ever use it (have an oil extractor instead). This is like the 3rd bolt that's in there - the previous one was stripped and so I had put in an oversized tapered bolt that has been working well but seemed to be a bit looser than usual a few months ago. I had noticed some oil dripping from it...tightened it up and seemed to be ok. This was just a bit before my brother took the tractor. And, one final issue is that the mower deck spindles aren't getting any younger either! There is a good amount of play in that center spindle. So, see what I mean? All in all, repairing it would still involve putting a rebuilt engine in a tractor and accessories that are all 40+ years old. Cost effective or not? I used to consider it a no-brainer to try and keep the old 129 running, but now am just not certain about it. Might this old tractor simply be pretty well 'used up' by now?