Hi, I just acquired a 1978 Ariens 20" mint condition snow blower. Model 932001 s/n 013983 with a Tecumseh engine H35-45503M s/n 8110B . It wasn't running when I got it but had spark. Would run with carb cleaner, so I purchased and installed carb kit 631893a, and because it was that I also old installed Points 30547a, condenser 38540b and new plug .
Set the points per Tecumseh repair manual and torque the flywheel according to specs. Engine ran fine for one snow storm but what I noticed it took about five mins before I could go to full throttle or the engine would die. Once warmed up it seemed fine especially under load. Then after sitting for a few days it was harder and harder to get it to run at full throttle. Figuring it had to be carburetor issues I removed it again and this time I removed the welsh plugs (not having done it the first time) and found nothing unusual in there. Cleaned carb. again and ran it through the ultra sonic cleaner twice. Reinstalled and same conditions except now I can't get it to run past half throttle no matter how long I let it warm up. Choking it makes not difference. Oh I forgot to mention this as the diaphragm carburetor. Though I have been working on small engines as a hobby, since I was kid, this is the first time I've seen one of these on a Tecumseh engine. The Tecumseh manual goes into quite a bit of detail so I feel a lot more comfortable with it now. So given this background information I was wondering now if there is anyone that has experience with this engine and diaphragm carb and might have a suggestion of what would cause the engine to want to die as soon as I go past half throttle. I'm using fresh VP racing fuel with no ethanol.
I was told that there are techs on this site that have a vast amount of experience and this would be the forum to try.
Thanks for any help you can give.