Hi everyone, I just started with the forum but I've been doing a lot of research on here the last few weeks. I just want to clear things up on a few questions I have.


So, a couple weeks ago I bought an early 1970's JD 726 with the Tecumseh H70-130158 engine. This thing is a beast. But it has been very temperamental for me. First thing I did was adjust the carburetor and that was a big help. Second, I changed the oil to 5w-30 from 10w-30 but it seemed to be a lot more temperamental. So i went back to 10-w30. It was still running weird so I ended up replacing the gas cap and now it runs great.



But anyways, this motor has always used 10w-30, so I was wondering if I should try switching to a semi-synthetic 5w-30 or just keep using conventional 10w-30?


Secondly, I am thinking about doing some other maintenance on it. Possibly replacing the head gasket, breather assembly, and the belts. So, one of the questions is, how do you know if you need to replace the head gasket? Also, is there a way to replace the belts without removing the auger from the body of the snowblower?


I am sure I have other questions but these are the main ones.


Thanks!

Oh and another question, what type of oil should I use in the auger differential?

Welcome to the forum!

I run synthetic Mobil 1 5W-30 in my Tecumsehs (more recent than yours). Personally, I think going to synthetic is fine.

If the head gasket and breather assemblies are working OK, why replace them? A failed head gasket can cause lower compression, possibly some visible smoke or oil around the head.

Belts, on the other hand, can weaken/stretch, and be worth replacing proactively. I'd keep the old ones around as spares, in case a replacement belt fails in the future.

For auger gearbox lube, what does your manual say? It's being discussed here presently:

https://www.snowblowerforum.com/foru...rm-drives.html

I don't think there's a single correct answer. It depends at least in part on what kind of gears you have, and their materials.

Don't replace the head gasket if it's working. You have a chance of snapping a head bolt.

Use synthetic oil, any weight.

I have a JD1032, my manual calls for 5w-20 for the gear case. The level should be 1"-1 1/2" from the top.

I don't replace belts unless they are ripped, torn, ready to snap, slipping, or stretched too much where they are slapping.

To replace the belts on my 1032, you need two people, one to hold the handlebar as when you remove 2 bolts, the handle will fall. There is a rod on the bottom and the handle tilts on this bar when you remove the 2 bolts.

Well I just used it a few minutes ago. Would hardly run on full choke with half speed, so I adjusted the high speed on the carburetor and it ran great. When I shut it down, I heard a knock and now it won't turn on at all. String is very hard to pull and even the electric start won't do it. Any suggestions?

Check your oil level. Hope it's full or at least has enough. Make sure you're in neutral, clutch not engaged etc when pulling on the rope too.

Oil is full. Changed it a few days ago. Took the plug off and pulled the string a couple times and could feel aircoming out the hole. Spark plug was a little gummed up so I cleaned it and engine still won't start. Seems the engine is flooding after 2 or 3 pulls

Anyone?

The fact that it got difficult to turn the engine seems interesting.

Is it possible the carb's needle valve is not closing properly, and is allowing gas to overflow, into the engine?

How are you trying to start it? As in, prime X times, full-choke, then pull cord, etc.

Welcome to SBF!!!
You say you got the blower and adjusted the carb, By the sounds of it you need to pull the carb and clean it then re adjust. If you adjust a dirty or fouled carb to make it run better most times it will not be good for the next running as in your case.


If that is flooding over by the needle and seat then it complicates things as well.
Certainly keep track of your oil as not to fill the crankcase with flooding gas if this would apply to your style intake on your tec.