hs40 finished.

[anthonyg]

Its a late 1980's that's been converted to recreational done in white and older decaling on it (placed incorrectly I might add). I have built a few like that, you have to use that shroud style with electronic ignition to clear the coil pack. I Have a new in the box full Chrome kit for that era engine in my office closet right now and I have some lighting systems and ball bearing late model parts so I will be building a few more of them one of these days.

They made recreational engines well into the 90's for the HS, and into the 2000's on the small H. But the flag decaling ended in 1978 and the recreational maed engines just got whatever the decals were at the time.

so you need a late model block and an old bearing style crank and side cover. and a new style lighting coil. but what year is that blower cover and can one be found. anthony.

 

[anthonyg]

I go to a powder coder that does high volumes in black. And he’ll sandblast and paint in either flat, semi or gloss black for $20 to $30 ( depending on his mood) for all the parts on a motor.

On your decal placement I think Mark was referring to the oil decal being in the wrong place. But I’m with you, I will often put it there. It depends on the motor. If I’m using a front mount gas tank I will usually put the decal where you put it. If I’m using a remote gas tank then I’ll put it in the proper place. The flag logo might be just a little bit low. But I don’t think anybody’s going to give you any heat about that!

You did a really nice job it’s a really good looking motor. I mean it’s not my style in that I think the paint seems way too shiny and way too thick. But man it sure does look good!

If you really want a light I guess you got to spend the money for the fly wheel and magneto. What I found is that people sell junk mtd minibikes and throw in the old Tecumseh motor, and you can usually rob those lighting parts on the cheap

it is mandatory i find a reasonable price for blasting and powder cote. stripping the parts by hand with sunny side two minute stripper and a wire brush is not the way to go. if i find myself building many more of these things i might put together a small blast cabinet and put a old electric oven in the garage. for the powder cote. anthony.

 

[cfh]

it's my opinion, but you're way over thinking this stuff.

first you don't need a ball bearing side cover/crank. unless you are turning big RPMs, there really is no big upside to that (expensive/rare) set up. i have several original motors with ball bearing side covers/cranks. do they run faster? hell no. do they run better? hell no. I'm running a bunch of HS50 motors with big cams too, and they are all bushing side cover/crank model. They work just freaking awesome. Don't get drunk with this kool aid that it needs to be ball bearing or nothing. i mean sure if it doesn't cost you more to have a ball bearing side cover/crank, go for it. but don't spend big money on this unless you're making a motor that's spinning more than 5000 rpm (or you're riding your minibike to Mexico!)

as for the rounded top blower housings... no HS50 ever had that. So unless you're trying to make your HS50 look like an old school 1968-1972 HS40, there's really no point in doing that. It involved getting a 32517 flywheel (generally expensive) and the blower housing (generally not too expensive). But if you're hell bent on getting that 'look', go for it. It will cost (mostly for the flywheel that is needed to work with the round blower housing). I just bought a rounded H35 blower housing on this site for $30. Sure it was rusty, but after your powder coat guy blasts it, that problem goes away.

Here's a Rupp motor I just did. It's not an original Rupp, it's an HS50 that I made look like a 1971 Rupp HS40. I used that rusty blower housing and a 32517 flywheel. I did this for no other reason than my personal entertainment. Will the bike go faster with that blower housing/fly wheel? hell no. But for a 1971 Black Widow, it does give 'that look.' I'm using Dellorto slide carb here (because that was the performance carb available for Tecumseh in 1971.)

I'll tell you what the single biggest/best thing you can do for any of these Tecumseh motors... get a freakin' better carb! The original tecumseh carbs BLOW. You're throwing away free performance using the original style carb. Get a slide carb. The 16mm style work great. Or you can bump it to 22mm. If at some point you're going to a bigger cam, the 16mm won't quite give you "everything" that a good 245/255 style cam will provide. But if you're running an otherwise stock motor, the 16mm carb is cheap and easy. It's free performance, at about $15. It looks way cool too. Your motor looks faster with it! ha!! But really it does make the Tecumseh a much better/faster motor.

 

[cfh]

I have 40 restored 1970s minibikes in my garage. Except for 3 with predators (a chopper, and two Fox 16" wheel models), they are *all* using rebuilt Tecumseh HS40 or HS50 engines with a torque converter. I would say less than 5 of those were original "mini bike" motors (survivors.) So that's over 30 Tecumseh motors, that formerly were snowblowers (mostly HS50). I've played around with all the options in carbs, cams, ball bearing side covers, honing, boring, clutch, you name it. I've dicked around with all this stuff trying to figure out what is worth the money, and what is not. I've come to this conclusion...

the HS50 tecumseh is the best motor in the tecumseh line. It's readily available, and parts are generally out there. I don't work with H35 motors (because it's the same cost to rebuild one of those, and no billet rod available, and damn it's just 3.5 hp!) I don't mess with H50 motors either (harder to get parts, no billet rod available, and it's stupid BIG and heavy.) Generally I don't mess with HS40 engines either. Though the HS40 motors do have enough power for my fat ass, i just prefer the HS50 motor (if given a choice.) Old 1970s and 1980s snowblowers are easy picking up here in michigan, and are generally lightly used. They are an excellent core if you want that original Tecumseh mini bike look. And with some minor tweaks, they run damn well and can (almost) compete with those stupid (stockish) predator motors. And if you want to make an HS50 look like a 1968-1972 HS40, it is do-able for a reasonable amount of up-charge in parts.

Again i stay away from H50 motors. They are just too wide. Put an HS50 motor in something that had a H50 motor, and you'll end up with that 'look' (still), but a better handling and more comfortable mini bike. at least that's my experience with that motor.

 

[massacre]

I also have noticed that the lighted flywheels and coils are going for higher prices. Same with small round shrouds and baffles.
It’s almost like people know they are rare and in limited supply, and pricing them accordingly lmfao.

I paid $200 plus “shipping” for an hs40 lighted flywheel and coil. Ouch. Then it took me like 4hrs to clean it because it was so dirty. Had a couple small nicks too.
But it has worked great so far and the motor has billet rod and cam and springs and turning high rpm.
to me it was worth it since I needed one and didn’t have one.
If you need something right away, it ends up costing more but if you can afford to wait for the right deal, it will be cheaper.
Same old same old

 

[massacre]

Also
I do agree with CFH about the slide carbs, they completely change the way the “bike” rides, a 16mm is great for a stock motor, but not for modded high RPM engines in my experience. Just not enough fuel delivery at high RPM.
A properly set up 16mm carb will pull just as hard from idle right on up to governor RPM, as a 22mm though. I was really surprised at that.
But after 3600ish RPM, it is just way too lean on my Hs50 which is usually turning 7000 rpm with the 22mm.

And the BB sidecover, I love them. They are expensive and more of a pain than a reg bushing cover, but I just like the design of it. Again my engine is turning high RPM so it is worth it to me with the tav.

 

[cfh]

Yea the lighted Tecumseh flywheel/coils are crazy. That's why i look for people selling junk MTD mini bikes. They always put in a predator. but ask, often they have the original tecumseh. and most of the trail flights were lighted. I have a pile of old HS40 motors (some with holes in the case), but with decent flywheels and lighted coils. And MTDs are dirty cheap (at least here.) They get no respect compared to Rupp or Speedway (or even Fox.)

I have several restored trail flights. They are actually *awesome* mini bikes. They handle great. the leading link front fork and just the feel of them is awesome. They look a bit weird, but they ride better than rupp/speedway/fox. well the 14" wheel speedways ride pretty damn well too.... but MTDs are easy to find and cheap. Speedways not so much, they are rare and generally expensive.

Another thing i have been playing with is the lighted coil add-on for CDI ignition Tecumseh's. It's only 350ma of power (compared to 3 amps), but it works quite well with an LED headlight. It's a cheap way to get lights. And really easy to install. The only downside is you get flicker on the LED headlight. Because there's only one magnet on the flywheel, you get lower power and it's not smooth like the 3amp points model flywheel/coils.

 

[cfh]

Yea Mass you're spinning BIG rpm's. Totally makes sense that you want a ball bearing side cover. But i don't run that hard. On my cam'ed motors i'm probably 5000 rpm tops. And as a side note... if you run 1970s Fox's with big wheels, say 16", no Tecumseh (hot or not) works very well. That's why the few 16" wheel bikes i have get those damn predator motors. I have one 16" wheel Fox with a HS50 with a big cam and carb, and it just doesn't go as well, as say the 10" wheel speedway and 12" wheel rupps with the same set up.

 

[massacre]

so you need a late model block and an old bearing style crank and side cover. and a new style lighting coil. but what year is that blower cover and can one be found. anthony.

If you want to run the skinny shroud, you will need to run a points ignition because the external coil is too wide for the skinny cover. I also like the skinny cover because it gives me more room on the footpeg on the right side. This is an off road “bike” so it’s more important than a street byke.

I swear there is a thread on all of this, because I went through this recently. Ended up using h35 shrouds and baffles on Hs50 engines with points and skinny flywheels. The lighted flywheel engines have studs for the recoil for clearance. Ended up drilling out the nutserts and welding in some studs for mine. Worked like a charm.

I’ll see if I can find the thread.

 

[markus]

so you need a late model block and an old bearing style crank and side cover. and a new style lighting coil. but what year is that blower cover and can one be found. anthony.

that particular shroud was used commonly 1984-1989 for the most part. Like I said above it had to be used to clear the ignition coil. But, It can actually be used on any small frame engine back into the 1970s on the steel flywheeled engines (and Early/first production HS50 thick aluminum wheel). The spacing is the same for the flywheel and fins and the back plate matches the mid 1970's style. As an example, you could bolt it onto your just finished HS40 with no modifications whatsoever an it would be fine to use. and you can use it on newer engines as well to be rid of the big fan looking recoils too, you want a screen for the flywheel cup though. That is usually the reason I use them, to backdate the look of a 90's built electronic ignition style engine.

So with that said, you can mix and match the parts (old and new) you just have to match the flywheel taper to the crankshaft and or decide which style ignition system you want to run.

 

[anthonyg]

well that was a lot of interesting reading. gonna reread the whole thing again in a day or two. im already sorry i found the picture of that beautiful and unique hs40. in a few days i will be convinced i need one.

 

[cfh]

Mass, the blower housing on the HS50 i showed above (rupp) is using an H35 round blower housing with a 32517 flywheel. it has that look you like! personally i don't see any advantage to the round blower housing other than the look. I have not noticed any issues with the steel flywheel/cdi flywheel square housing, in terms of comfort or room. I ride off road too! i have 10 acres plus 100 acres right across the street! just needs to warm up...

 

[markus]

well that was a lot of interesting reading. gonna reread the whole thing again in a day or two. im already sorry i found the picture of that beautiful and unique hs40. in a few days i will be convinced i need one.

too bad none of it pertains to the actual question you asked, Happy new year!

 

[anthonyg]

too bad none of it pertains to the actual question you asked, Happy new year!

happy new year.

 

[massacre]

True. I have a fat aluminum flywheel Hs50 engine and it has the fat shroud. It is also a points engine, so theoretically

Mass, the blower housing on the HS50 i showed above (rupp) is using an H35 round blower housing with a 32517 flywheel. it has that look you like! personally i don't see any advantage to the round blower housing other than the look. I have not noticed any issues with the steel flywheel/cdi flywheel square housing, in terms of comfort or room. I ride off road too! i have 10 acres plus 100 acres right across the street! just needs to warm up...

The skinny shroud gives me more room for my right foot. I rode it for like a year with the fat shroud too!
I can use either one but it just gives me a better bite on the peg and better feel when riding my MTD.
I like the look of either engine, I didn’t make the choice because of the look

 

[cfh]

Mass, i have several 1972/1973 HS50 motors with the alloy fat flywheel. i have not tried a round housing on them. are you saying it will work? because the round housing sure doesn't look big enough! i always use a 32517 flywheel when i go with a round top blower housing on the HS50...

by the way i rode the black widow around a bit more tonight. it has the big cam 245/255 style that i cut myself. arc rod. dellorto ua19s carb, open BW exhaust. the original rupp torque converter isn't handling it very well. i might have to convert to a comet style 20 clone driver on the motor. the motor gets up and goes on the rpm (fast!), and the torque converter slips pretty bad and can't keep up...

 

[massacre]

No the skinny shroud will not work with the fat flywheel

 

[anthonyg]

just started the hs40 for the first time. i gave the epoxy paint two weeks to cure. it started on the second pull on choke with the carburetor needles at 1-1/2 turns out. i only ran it 15 or 20 seconds. didn't adjust it at all. i was tempted to throw it on the bike but idon't want to scratch it. anthony

 

[Joe51]

Just curious & maybe missing something here so forgive me in advance...It looks to me from the pictures that the block was originally
a snow blower set up. Not an original Rupp HS40.
Again sorry if I missed something
Regards,
Joe51

 

[anthonyg]

Just curious & maybe missing something here so forgive me in advance...It looks to me from the pictures that the block was originally
a snow blower set up. Not an original Rupp HS40.
Again sorry if I missed something
Regards,
Joe51

the block is a1970 rupp hs40 . the blower cover is off a1972 hs50.