Side Popper questions

[davidlamb78]

I got three free motors yesterday. One is an older two stroke. One is a little Briggs that is mostly complete, and I got what I think is a side popper. It appears to be removed from some kind of snow thrower or old power tool. There are some numbers stamped in the top cover. It has a large priming bulb in the side of the shroud. The entire thing, including the tank, is painted red or orange.

First off, how will I know if this is a side popper? Is it simply because the exhaust is on the side, and that makes it a side-popper, or is this a similar situation to the old Mopar Hemi vs. the new Hemi? I know the original Hemis are sought after, and most will say that the new Hemi doesn't even compare to the older ones. Are there some older Tec motors that are side poppers and are considered to be better than the newer versions?

I'm curious because this motor came on a go cart. The guy that gave it to me said the motor wouldn't go fast enough to engage the clutch. I fired it up. It runs, and it doesn't have a problem getting up in the RPMs without a load. I'd like to stick this on an older bike, and I was hoping to just stick it on and go. It appears that I might need to check compression, do a clean up, and possibly rebuild it. I'll know more when I open it up.

If I end up rebuilding this thing, is there anything I should know about these little gems before I tear it apart?

 

[Havasu Dave]

Side popper mean side exhaust. I found out that the earlier genre of the Tecumseh- Lauson engines had smaller bores for given HP ratings than later ones. What this means is that it's difficult to source oversize pistons and rings for them, since part numbers don't cross on the older ones, and the plethora of newer model parts for sale are listed as "H30 or H35" and are larger bore than an earlier one.

This is what I ran in to with an H30 I wanted to rebuild for a 1962 "Fun Kart." So its still on the shelf, a motor way out of spec, and no parts for it.

You may want to remove the head carefully, preserving the gasket just in case it's a small bore type, then mic out the bore and compare with the Tecumseh manual to see what genre you have. If it runs, heck you already won.

 

[davidlamb78]

Thanks, Dave! This is exactly the kinds of stuff I'm looking for!

 

[Havasu Dave]

I don't know how much I helped, LOL. I assume you cant ID it with any tags or decals. If it ends up being an early Tec, or a Lauson, I'd be very selective and careful about tearing it apart. I've been looking for a 3HP Lauson for a long time.

 

[markus]

If numbers are stamped in the top and it has a primer bulb on the cover face its going to be mid 70's and up and can range in HP use the numbers as a start point.

 

[Havasu Dave]

Since it's been a long time, I went back and checked. The 82 and prior H25 and H30 had a 2.3125 bore. After 82, the H30 had a 2.5" bore.

The Cyl main was around .200 smaller as well.

Checking further, I found the TVS 75 and LEV80 (both vertical engines) shared that 2.3 bore. Standard pistons and rings are available, but I didn't find anyone carrying the .010 or .020 OS stuff for them. Just tossing this out there.

Markus, my H25/35 definitely had a button on the front, as well as some apparent carb heat set up for snow blower. I'd need a .020 over at least iirc the measurements of wear and taper.

 

[davidlamb78]

Okay, it appears to be an H35. That's the first part of the ID stamped in the cover. It does have a Briggs carb on it, but I have an older Tecumseh carb that came with it. I will clean up the tec carb and put it back on.

 

[markus]

yea thats mid 70's early 80's configuration, the last set of digits in the stamping will tell the date, I would say its post 1976 because of the head. The h35 and fist set of digits can be used when searching for parts explosions and numbers on sites like partstree.

 

[owend]

I have used them on several bikes and they always ran well for me, just not the fastest thing out there:laugh: send me a pm and I'll get you a picture of the linkage set up.