H35 intake differences

[markus]

today I dug out some engines getting ready to get something together for my Lil indian. I have decided to use an H35, but I haven't decided if I want to make it lighted or not.

I pulled to 2 H35's that I have left out, the one is a rare lighted 1969 steel sleeve off a 1969 Rupp scrambler and the other is a 1971 off probably a powerdyne as it was silver at one time and had the big 148cc decal on the pullstart.

It looks like roughly around 1970 Tecumseh did away with the steel sleeves in the blocks from what can tell. i started to pull the 69 apart and thought the intake looked like it had an awful small bore inside. So I pulled the one off the 1971 and its hogged out alot more and the casting number is different on intake as too.

I compared the valves and inlets and bores just in case maybe a tag was incorrect. everything is the same sizes, I had another pre 70's H35 that was junk awhile back and I pulled out the stuff I didnt throw out and the intake is the same small bore.

So they ditched the lined cylinder and opened up the intake for whatever reason when the made the changes. Anyone think running the later intake would be a plus on the earlier engine :shrug: Its a 4" wheeled lil indian so I'm not going for performance, The smaller intake might be better for low end though :shrug:

 

[oldfatguy]

I have a few early 60s toro Tecumseh hs35 engines that have the intakes with the smaller port. All the mini bike intakes that I have seen were all with the large port. I think that the smaller port intakes were used on power equipment to give better low speed torque and to limit the engines top speed. They probably could turn up on a mini bike and would work fine if you aren't looking for high rpm performance. I have an all original 1968 hs25 that I should check to see which intake it has.