Need help with some basic Tecumseh questions

[mwmurrell]

All of my experience is with clones because they are cheep and easy.

I recently bought a bike that has a Tecumseh 3.5.

The positioning of the intake places the carb and airfilter in really bad positions directly up on the fender.

The engine runs well but isn't made for a minibike ( i think it came off a snowblower because it has a plug-in electric start).

All i want to do is know
A) How to identify this engine (what do they go by when i search for parts)

B) Iv been seeing different intake manifolds available but none for the 3.5 ( i dont think at least). Something about a slanted manifold that putts the carb in a better position.

C) The exhaust port is threaded but i would like to put some kind of header on it. Do they make these basic hop up parts for the 3.5 and if so where?

Pics will be on shortly

Thanks for the help. I pretty much rely on you experts!

 

[zeeman]

I'm no expert, but depending on the year it was manufactured, you should find some numbers either stamped into the top of the recoil shroud, or embossed on a plate on the front right hand side of the engine. Newer Tecumsehs, like from the 90's I believe had a sticker on the back of the shroud. Depending on what it was used for originally, the numbers could be somewhere else. It should start with 'H35, then some numbers, then a serial number. You can put a header on it if it has two threaded holes on each side of the exhaust similar to the way the carb mounts. If you have to have a header, I'm sure you could thread a piece of pipe into the block and weld on what ever design you want. I don't think there are many hop up parts available except maybe some special order things. I'm sure others will chime in.

 

[The Restore Kid]

Yeah you can throw a pipe on it easy enough.. :shrug: I don't think there are any after market connecting rods for 3.5 but as long as you aren't running it on alcohol and dynamite, it should hold together.. Some of the bigger engines are hand granaders, but the 3.5 Tec is pretty tough...

As far as intake manifold all I can picture being wrong is it being a really modern one with the 3 foot long stupid ass thing with a AAA battery sized hole through the middle.. :hammer: Those things are trash for that reason alone.. :laugh: Any other standard pre-1995 Tec 3.5 intake should work fine for you.. :shrug: %85 of the old bikes CAME with Tecumsehs specifiaclly because they fit in bikes so well..

Nothing else, they made adapters for lawn mowers and stuff that will re-route the air filters orientation...

the TILTED intake manifolds are for HS series engines and will not even bolt to your motor.. If ya could get one on it, it would just exacerbate the problem ten fold.. :laugh: Those ONLY work on tilted framed minibikes..

 

[chazdaddy]

I am no expert, but the air filter adapter plate on my H35 puts the air cleaner in the center of the bike too close the to rear fender, same problem as you described. I took one off a HS50 and it offsets the air filter to the right out of the way. You may want to try a different air filter adapter plate (the flat plate that is attached to the carb with 2 screws that the air filter is mounted to). :smile:

 

[mwmurrell]

here are some pics to help

I understand what both of you guys are saying

This project is not meant to be high performance... the air filter and exhaust are the only two things im changing on the engine. Not only does the exhaust flange have 2 threaded holes, the head is threaded for a pipe.

so from what im gathering 3.5 Tecumseh intake manifolds are fairly interchangeable? This is more vintage than modern so nothing fancy. Its going on a toad.

You say HS50 and H35. Where can i find out which engines those numbers represent. What is the 3.5HP....Its hard to shop for parts because i dont know what engine i need to order the part for...i thought they would do it by hp...

Here are some decent pics....open to suggestions on how to remove electric AC starter....idk if i can just take it off or not.
you can see how the air filter literally sits on the fender. almost anything different will work. so the 3.5's are somewhat the same as far as that manifold goes and it looks like i could locate a different shape one if i really want to

btw is the long spring leaver in pic (3649) with several holes running down it... is that part of the governor and if so how do i eliminate it? same way you do the clone engines?

 

[Motra]

That looks more like an HS40 with that port arrangement. An H35 is 3.5HP, HS40 is 4HP and HS50 is 5HP.

 

[jrzmac]

You dont need a new intake manifold. yours is fine, sometimes they come with a real skinny intake that you HAVE to change but yours is o.k. all you need is a new air filter assembly. Outdoor Distributors - Lawn Mower Parts . also, I wouldn't recomend removing that governor arm. If you take that off and leave the gear intact inside the engine, you could run into problems down the road. if you're having problems running it the way it is, take some pics of the back of the engine, the throttle mech., and the carb. something could be hooked up wrong or something? there's certain ways things are supposed to be hooked up, and certain holes etc. but no 2 engines are alike, and most of the time you have to play around with the linkages to get things going. some springs will be longer than others, or connecting rods will be longer etc. make any sense???

 

[The Restore Kid]

That looks more like an HS40 with that port arrangement. An H35 is 3.5HP, HS40 is 4HP and HS50 is 5HP.

X 2 :thumbsup:

You dont need a new intake manifold. yours is fine, sometimes they come with a real skinny intake that you HAVE to change but yours is o.k. all you need is a new air filter assembly. Outdoor Distributors - Lawn Mower Parts . also, I wouldn't recomend removing that governor arm. If you take that off and leave the gear intact inside the engine, you could run into problems down the road. if you're having problems running it the way it is, take some pics of the back of the engine, the throttle mech., and the carb. something could be hooked up wrong or something? there's certain ways things are supposed to be hooked up, and certain holes etc. but no 2 engines are alike, and most of the time you have to play around with the linkages to get things going. some springs will be longer than others, or connecting rods will be longer etc. make any sense???

X 2 :thumbsup:


Yeah, you can also take the standard round air filter, and bolt it on up side down to gain clearance too.. Many, pretty well ALL of the tilted motors, came upside down..

Whatever ya put on it, might hit your choke arm though.. :doah: Might have to modify that some :blink:

 

[mr.modified]

You may be able to bolt the intake on upside down, making it a down draft. Tecumsehs usually have the manifold bolt holes offset from the port, but you can reshape the manifold a little with a file or dremel. Of course you would have to hook the throttle back up somehow. Not sure if you would have a clearance problem at the top.

 

[zeeman]

Hey MW, What you have there is a Manco Thunderbird minibike. I agree that the engine did not come on it. It would probably have had a Tecumseh H35 (3.5 hp). Talking about removing that little arm thingy is a no-no on this forum, just so you will know. I put an air filter unit off of a Clinton engine on my H35. There is a thread on it in the project log section. I started off with the same bike you have.

 

[mwmurrell]

Im sorry about the governor talk, and thanks for informing me. I was un aware of that rule. But that is the mechanism that works the governer right?
Actually my first bike was a brand new lil indian with hs35.
I have never modified a briggs or tecumseh at all.....not even bolt on parts.
I have lots of experience with modifying clones so im taking this Tecumseh engine as a learning process. I have a GX200 ready to go which is actually going into the Thunderbird. Its Dads birthday present (lots of pics in the projects forrum).

So it looks like 4hp to you guys and exhaust, intake manifold and air filter should be easy enough to locate if i want them.

Thanks for all the help. I really appreciate it.

BTW can i remove that electric start and is the starter worth anything to anybody> TY

 

[zeeman]

The arm you are talking about is the governor arm. Sure, you can remove the electric start. Post the starter for sale in the for sale forum. Who knows, someone could be looking for a used one. I have not seen your build in the projects forum, but I'll look for it. Good luck on your project.

 

[Mark G]

Yep that's either a 4 or a 5hp. I just put the same motor, on the same bike. put an extra link in your chain and move the motor a touch forward, that will just get the air filter to clear the fender. You will have to bend the choke lever too. I use a round Clinton one (same dimensions as a Tecumseh) on mine and it works real well. If I get a chance today I'll get some pics
Throw the electric starter on ebay, you'll be surprised at what you get. Just put HS40-HS50 in the title and you'll be all set. :thumbsup:

 

[The Restore Kid]

Yep that's either a 4 or a 5hp. I just put the same motor, on the same bike. put an extra link in your chain and move the motor a touch forward, that will just get the air filter to clear the fender. You will have to bend the choke lever too. I use a round Clinton one (same dimensions as a Tecumseh) on mine and it works real well. If I get a chance today I'll get some pics
Throw the electric starter on ebay, you'll be surprised at what you get. Just put HS40-HS50 in the title and you'll be all set. :thumbsup:

Snowblower... :lol:

Put snowblower in the title, about November 30'th Tecumseh H30 H35 Hs40 HS50, SNOW BLOWER 110 electric starer... You'll be amazed what it brings.. :lol:

 

[mwmurrell]

thanks for the heads up on the electric start. I have a thread in the projects forum and also i think some uploaded pics. today i figured out what im going to do with the forks. Then engine mounting.