Engine ID HELP!!!!! H40 or what?!?!

[Dave Moore]

Hello everyone,

I just found this forum and have searching around a bit to try and ID my engine, but so far have only confused myself more lol.

The tag on the shroud says its an H40 55805a and the DOM is 7352. But from what im reading is that an H40 is really old and there are only HS40's nowadays (past 20 years).

Alright, let me back up here, all I wanted to do was order a new carb for this thing considering the one I have is really worn out and the bike wont idle well, if at all, hesitates and bogs upon acceleration and then just stalls. The number I got off the carb is hard to read but says 5123M7K which equates to a Tecumseh #640134, and which from what Ive come up with is for an H35, but this is supposedly an H40. Now, did some more researching on here and it appears others have this carb and have upgraded to a #632230, so I dont really see a problem there.

All I want to know is what code is my engine? Because I have other gaskets and parts to order for it.... Everything Ive read so far is leading me to believe its actually an H35, but I googled an H40 for a minibike and came up with this picture, which is EXACTLY my engine. ut:


Heres my engine, half taken apart to find out what I have here. Thank you for any replies.





PS, sorry for small photos

 

[capguncowboy]

H40. I think it's a 1997 model if I'm not mistaken

The sub model number is 55805A

When you search for parts, use "H40 55805A". Part tree will tell you the original parts number and list compatible parts if they're available.

 

[Dave Moore]

Thank you. Yea, late 97, like on christmas day, Merry christmas to me haha. So im not crazy then. When I got this engine and bike, everything was torn apart or missing, so I had to piece it all back together, and I wasnt sure if the shroud was from another engine or not. And now Im really tearing into it to make it nice again and not all rigged together.

So would I be alright with buying that replacement carb I mentioned?

 

[markus]

The H40 of that era is the same as an H35 of that era. if you cross the part numbers there is nothing different I dunno why they bothered to badge them that way. I just crossed my 2000 H35 with your 1997 H40 and every part number is the same.

the 632230 is intended for the larger "medium frame" engine from years before, while the body of the carb is basically the same, the throttle shaft is set up to pull instead of push and you wont be able to utilize it unless you change out the shaft.

I dont know what a good replacment carb is for the small frame H/HS engines is offhand, if you going through the trouble to replace it, you would probably want to swap to fully adjustable style instead of the stock fixed jet you have now...but I am pretty sure you can just install the adjustable jet on these too. you will loose the inlet for the breather hose on most replacement carbs which is not big deal.

Lots of guys buy the replacement carbs and there is info on this site and someone might chime in with numbers or a link, I've just never ordered one myself as I have a pretty good supply of old carbs and I rebuild them usually

 

[Dave Moore]

The H40 of that era is the same as an H35 of that era. if you cross the part numbers there is nothing different I dunno why they bothered to badge them that way. I just crossed my 2000 H35 with your 1997 H40 and every part number is the same.

This is what Ive come to find out as well from all the research Ive done so far. I was just wanting some reassurance; Ive been looking at exhausts, and all the ones Ive seen appear to be for exhaust ports on the flywheel side and not the clutch side like mine, so its kind of a pain. I decided to make my own...

What exactly do you mean by the shaft is set up for pull and not push? Push meaning the governor shaft pushes the throttle open? Im in the process of deleting the governor and just using the throttle linkage to acuate it. Ive already ordered the above mentioned carb and hopefully Ill see exactly what youre talking about, Im a mechanic by trade and have a really decent of how things work so Im sure I can figure out a way to make it work.

I got that carb number off of this site on a few different threads..... all I wanted is full adjustability of the carb and this option seemed the best so far. There are soooo manyyyyyyy carburetor styles out there.........

 

[markus]

This is what Ive come to find out as well from all the research Ive done so far. I was just wanting some reassurance; Ive been looking at exhausts, and all the ones Ive seen appear to be for exhaust ports on the flywheel side and not the clutch side like mine, so its kind of a pain. I decided to make my own...

What exactly do you mean by the shaft is set up for pull and not push? Push meaning the governor shaft pushes the throttle open? Im in the process of deleting the governor and just using the throttle linkage to acuate it. Ive already ordered the above mentioned carb and hopefully Ill see exactly what youre talking about, Im a mechanic by trade and have a really decent of how things work so Im sure I can figure out a way to make it work.

I got that carb number off of this site on a few different threads..... all I wanted is full adjustability of the carb and this option seemed the best so far. There are soooo manyyyyyyy carburetor styles out there.........

the larger engines (old style H40) pull the arm on the carb the smaller style (what you have) push, the shape of the arm is different and you cant really use the arm.....the carb body however is really the same, so you can simply unscrew the butterfly plate and yank the throttle shaft/arm and swap them over usually. just make sure the spring goes back on the felt washer is there.

I Just built a header for this one, these engines like yours and the one i just bought the other day have a really small exhaust valve and port, Thin wall 1/2 tubing was the same as the ID of the port so made it a stepped header from that up to 1"

was this:

and I turned it into this over the weekend

I actually need to swap out my carb too as its not adjustable...at all. It actually (surprisingly) runs great though but now that it has the abilitly to breath much eaiser it wants to idle higher and there is no way to adjust it out. I just wanted to try it (just finished this weekend).

 

[Dave Moore]

Nice bike, I really like that blue on there! Mine is almost the same except for a longer frame. Ill see what I can come up with as far as linkage goes when the carb shows up. If I have to, Ill make a one piece bell crank and go from there.

I made an exhaust flange for it earlier today and I have a pipe thats a hair over 5/8" inner diameter that Im gonna weld on to the flange. Should I step the pipe to a larger size towards the end or am I OK leaving it one size?

 

[markus]

Nice bike, I really like that blue on there! Mine is almost the same except for a longer frame. Ill see what I can come up with as far as linkage goes when the carb shows up. If I have to, Ill make a one piece bell crank and go from there.

I made an exhaust flange for it earlier today and I have a pipe thats a hair over 5/8" inner diameter that Im gonna weld on to the flange. Should I step the pipe to a larger size towards the end or am I OK leaving it one size?

I like it stepped, I would have liked to do it a lot longer than I did but the frame is so dam short! The sound is pretty nice too, its really not too loud and its pretty "crisp" I guess you could say :shrug: not popping alot of backfiring and blubbering when coming off the throttle.

the other reason to step it is to get it up to a size that can fit muffler if needed, I got it up to 1" tubing which I have seen the clamp on muffs in that size and up.