Little help over here please.

[Fly5guy]

It appears I am missing some parts on this little project. I do not have solid rod going from the Gov arm? to the carb. At least I think that is what it is called. Nothing connect the throttle linkage to the carb. I also have noticed from pictures my choke lever is possibly installed on the wrong side and does not have anything for the grooves to index on. I do not know much about these bikes so any help is appreciated. I have already replaced the gas line and and added fuel filter. The tank was lined at some point and was failing. Luckily I was able to pretty much peel it right out. Very little rust in the tank, not sure why it was lined, its not leaking. The carb has been taken apart and soaked/ cleaned, before I started working on this. I got it to run, it will not stay running. I am going to dismantle the carb again and re-clean. Any other suggestions are welcome as to next steps. Thank you for your time.

 

[Triley41395]

It appears I am missing some parts on this little project. I do not have solid rod going from the Gov arm? to the carb. At least I think that is what it is called. Nothing connect the throttle linkage to the carb. I also have noticed from pictures my choke lever is possibly installed on the wrong side and does not have anything for the grooves to index on. I do not know much about these bikes so any help is appreciated. I have already replaced the gas line and and added fuel filter. The tank was lined at some point and was failing. Luckily I was able to pretty much peel it right out. Very little rust in the tank, not sure why it was lined, its not leaking. The carb has been taken apart and soaked/ cleaned, before I started working on this. I got it to run, it will not stay running. I am going to dismantle the carb again and re-clean. Any other suggestions are welcome as to next steps. Thank you for your time.

There are some great carb people here on this site that will likely chime in.
If it were me I would take the model number off the engine which should be on the top of the shroud above the pullstart and go to jacks small engines site and use the exploded view to get the part number. If that site doesn't have the parts you need put that number in on ebay and see if it pops up. I'm not knowledgeable enough to tell if that is an original carb or aftermarket. I would buy a cheap aftermarket carb from Amazon and try it. If that carb is original I would rebuild/repair it and put it back on.
Your almost there with a fine looking bike.

 

[Tom S.]

@Triley41395, pasting part numbers into ebay has been my pathway to many great finds.

 

[Fly5guy]

There are some great carb people here on this site that will likely chime in.
If it were me I would take the model number off the engine which should be on the top of the shroud above the pullstart and go to jacks small engines site and use the exploded view to get the part number. If that site doesn't have the parts you need put that number in on ebay and see if it pops up. I'm not knowledgeable enough to tell if that is an original carb or aftermarket. I would buy a cheap aftermarket carb from Amazon and try it. If that carb is original I would rebuild/repair it and put it back on.
Your almost there will a fine looking bike.

Thanks for the reply. Didn't know about jacks small engines. I'll do some digging. Thanks again.

 

[Triley41395]

Thanks for the reply. Didn't know about jacks small engines. I'll do some digging. Thanks again.

No problem, there is also a place on this site dedicated to just tecumseh engines, lots and lots of good advice there.
https://oldminibikes.com/forum/index.php?forums/tecumseh.34/

 

[bdjake]

You have a diaphragm carburetor, maybe the diaphragm is no good? you could buy a rebuild kit or a new carb. Usually these bikes have a bowl type carb, like what you would see on a snowblower. Yes you are missing the rod, you can find them online easily. You are also missing a nut on the gas tank bolt. looks like a real nice bike.

 

[Fly5guy]

You have a diaphragm carburetor, maybe the diaphragm is no good? you could buy a rebuild kit or a new carb. Usually these bikes have a bowl type carb, like what you would see on a snowblower. Yes you are missing the rod, you can find them online easily. You are also missing a nut on the gas tank bolt. looks like a real nice bike.

Yeah the guy that worked on it before me forgot to put them back on. I'm gonna check with him about the rod but might just look further into a new carb. If it were you would you do a rebuild kit for this carb or buy a float style? I believe all the pictures I've seen were float style. Where would be your destination for finding either of those parts? Thanks.

 

[manchester1]

I would just buy a float carb. 15.00 on eBay. Worry about that other carb later. Then you can hook the governor up properly. And yes, you are missing the linkage (metal wire). That linkage hooks on the governor and carb and is what controls your speed.

 

[markus]

Tecumseh part number for the link rod is #32698 You choke lever looks correct and someone may have just twisted it over at the top a little to clear the exhaust. you can verify its correct by looking to see f it has a flat spot ground into it between body and lever which should rest against the stainless tab that serves as a detent to hold it in the open/run position. on the HS40 with that carb it typically sits in the open/run position right above the air filter and pulls to the right to choke.

I cant tell if you exhaust is sitting to low or ??? That carb was very short lived during 1971 model year, your engine model number should be HS40 55331c and probably very late 1970 or very early 1971 serial number. They were coming out with the angled intake and bowl carb to replace the diaphragm setup. clearance for the choke lever on the new 1971 models with exhaust on the right of the bike rather than crossing over to the left was not good with the diaphragms.

A diaphragm carb needs to be totally disassembled to properly clean (that means the welch plug on the side and the one, on that particular version, found covering the main/high speed circuit check valve, under the diaphragm itself). There is a non serviceable brass check valve under it that main welch, you can't pull it out but you must make sure its very clean in there. your fuel also has to be squeaky clean since there is nowhere for dirt or debris to go but into the circuits. so if you tank has any problems you always going to have problems even with good filters.

That is the correct carb for your engine and, if original, is unique to the slanted application HS40 only, It was the ONLY diaphragm that ever was built, setup, and used for that size engine and only used 1969-early 1971. You can verify by looking at the number stamped in the mounting ear which will be stamped 356, if its stamped 379 than its from an H25-35 and the idle circuit is totally different and much smaller so it may not want to run correctly/well I just finished a full engine resto on a similar early '71 slanted application HS40 for a member with the same setup. and I just found another one of the HS specific 356 carbs which just came out of the cleaning solution and I will be rebuilding, great and hard to find carbs!

Here it is during break in

this is one I did a few years ago that is the same version as yours:

 

[bdjake]

Yeah the guy that worked on it before me forgot to put them back on. I'm gonna check with him about the rod but might just look further into a new carb. If it were you would you do a rebuild kit for this carb or buy a float style? I believe all the pictures I've seen were float style. Where would be your destination for finding either of those parts? Thanks.

IF I had this bike I would either rebuild this carb or buy a new diaphragm type. The float carbs need to sit level which requires a special intake or adapter. The diaphragm carbs eliminate the need for the special intake or adapter because they can operate at any angle. Amazon has them for $20, I haven't used them but probably work fine. Amazon will also have float style carbs that work well for like $16 or so and the adapter is at Blackwidowmotorsports.net. They also have many, many other great parts.

 

[Fly5guy]

Tecumseh part number for the link rod is #32698 You choke lever looks correct and someone may have just twisted it over at the top a little to clear the exhaust. you can verify its correct by looking to see f it has a flat spot ground into it between body and lever which should rest against the stainless tab that serves as a detent to hold it in the open/run position. on the HS40 with that carb it typically sits in the open/run position right above the air filter and pulls to the right to choke.

I cant tell if you exhaust is sitting to low or ??? That carb was very short lived during 1971 model year, your engine model number should be HS40 55331c and probably very late 1970 or very early 1971 serial number. They were coming out with the angled intake and bowl carb to replace the diaphragm setup and clearance for the choke lever on the new 1971 models with exhaust on the right of the bike rather than crossing over to the left was not good with the diaphragms.

A diaphragm carb needs to be totally disassembled to properly clean (that means the welch plug on the side and the one, on that particular version, found covering the main/high speed circuit check valve, under the diaphragm itself There is a non serviceable brass check valve under it that main welch, you can pull it out but you must make sure its very clean in there. you fuel also has to be squeaky clean since there is nowhere for dirt or debris to go but into the circuits. so if you tank has any problems you always going to have problems even with good filters.

That is the correct carb for your engine and, if original, is unique to the slanted application HS40 only, It was the ONLY diaphragm that ever was built, setup, and used for that size engine and only used 1969-early 1971. You can verify by looking at the number stamped in the mounting ear which will be stamped 356, if its stamped 379 than its from an H25-35 and the idle circuit is totally different and much smaller so it may not want to run correctly/well I just finished a full engine resto on a similar early '71 slanted application HS40 for a member with the same setup. and I just found another one of the HS specific 356 carbs which just came out of the cleaning solution and I will be rebuilding, great and hard to find carbs!

Here it is during break in

this is one I did a few years ago that is the same version as yours:

View attachment 287910

Your spot on on the model number. Serial Number is 1020B. What year would that make this? I did find the 32698 part number but nice to confirm thank you. I have no idea what is going on with the exhaust. I'll put a close up pic below. doesn't seem correct. This bike was in the back of a garage of the old farm house we bought covered with tons of junk, boxes etc. No clue how long it sat there. 356 on the carb as you said. Pic below. Not sure what kind of gasket was used originally, hard as rock but not metal. Then it appears someone used like silicone after. I'm actually trying to get this running to sell it. As much as I would like to keep it I have a tractor on order and well, a guy has to choose sometimes. If I choose to put a new carb on it would you be interested in the old one? I think I saw no selling stuff on this part of the forum so hopefully now breaking any rules for asking. Thanks again for the info. Very cool.

 

[Fly5guy]

IF I had this bike I would either rebuild this carb or buy a new diaphragm type. The float carbs need to sit level which requires a special intake or adapter. The diaphragm carbs eliminate the need for the special intake or adapter because they can operate at any angle. Amazon has them for $20, I haven't used them but probably work fine. Amazon will also have float style carbs that work well for like $16 or so and the adapter is at Blackwidowmotorsports.com. They also have many, many other great parts.

Awesome. Thank you for the info. I was seeing other older posts about the float style being level and was wondering about adapters etc.

 

[bdjake]

Awesome. Thank you for the info. I was seeing other older posts about the float style being level and was wondering about adapters etc.

Correction: Blackwidowmotorsports.net not .com.. Sorry.

 

[copyman]

I've used the slant adapter from black widow with bowl type carb and it works great. I would of used the regular slanted intake but very hard to find & ridiculous high priced original one. If not mistaken Black widow now has both the slanted intake & adapter in stock.

 

[Fly5guy]

I've used the slant adapter from black widow with bowl type carb and it works great. I would of used the regular slanted intake but very hard to find & ridiculous high priced original one. If not mistaken Black widow now has both the slanted intake & adapter in stock.

I got a rebuild kit for the diaphragm. Any idea what hole the throttle linkage is supposed to be in. Both on the gov and the carb?

 

[toomanytoys]

My rupp is running a non angled setup on the tecumseh and it’s never been an issue at all.

 

[copyman]

I got a rebuild kit for the diaphragm. Any idea what hole the throttle linkage is supposed to be in. Both on the gov and the carb?

Linkage for bowl and diaphragm Carb & Gov is covered really well in the Tecumseh L head service manual. Also the Gov adjustment in manual is important.

 

[copyman]

My rupp is running a non angled setup on the tecumseh and it’s never been an issue at all.

Good to know. I've read that before, just seems that the float would be affected sitting at an angle.

With the price of the original slant intake (if you can find one) I would of opted to use bowl carb without anything, but since the adapter is only $20 I went that route.

 

[Fly5guy]

Linkage for bowl and diaphragm Carb & Gov is covered really well in the Tecumseh L head service manual. Also the Gov adjustment in manual is important.

Found it. This is very helpful. Thank you.

 

[Fly5guy]

Ok. So I got the carb kit and installed all the parts. Got the bike running. Started pretty easily actually. It would idle well but would die when I gave it throttle. After adjusting carb I Got it running fairly well but had no power to the rear. So I took that all apart cleaned up and back on. After, I noticed the carb is leaking fuel out the choke hole. So its full. I soaked up as much as I could and let it sit overnight but now I can't get it to start. It just floods when I turn the gas on. Diaphragm and gasket are installed properly, no F on carb. Why is it leaking gas?

Edit: Well things have transpired, possibly for the worse. I noticed the connection from the head to the exhaust seemed wet. At about the same time I saw a drip come from the screw that is on the bottom of the exhaust. I am pretty sure this is all gas. I drained the oil, which did not seem to have any gas in it but was super black considering I just changed it. Pulled the plug. Now what? If only I would have utilized the new shut off valve on the new petcock I installed I most likely could have avoided some of this.