Couple questions about my new mini

[Generrader]

Hey guys, just got a second mini bike today. I believe it’s an old Taco mini bike but please correct me if I’m wrong. It has a Tecumseh 5hp OHH50 engine which turns out to be quite different in design from my other mini with the Tecumseh 3.5 so I’m pretty confused at the moment. On the 5hp one there is no on/off switch of any kind and no choke on the carburetor. It has the primer bulb style carb so I guess those don’t come with chokes? I tried to choke it manually by taking off the air filter and plugging the hole with my thumb but still no luck in getting the engine started. Not sure if the other guy ever had it running with that engine but part of me thinks it needs some type of ignition on/off switch to run? He said he got it off a lawnmower so maybe they are slightly different in design? I think that because when I look up the owners manual for the OHH50, Tecumseh mentions multiple things about the on/off switch and the choke. Part of me thinks the carb could be dirty and need and clean but the engine looks so well-kept and wasn’t stored with gas in it so that’s kind of hard for me to believe. Hopefully you guys can give me some insight and advice, I’d like some more knowledge before I start digging into the carb and messing up gaskets and what not. Any help is greatly appreciated. Sorry for the long post.

 

[Strigoi]

It didn't come off of a push mower, that's for sure. Every one I've seen runs a vertical shaft, not horizontal.

I know next to nothing with it comes to the Power Sport Tecumseh engines.

 

[manchester1]

I have seen that style engine on some of the newer Lil Indians. 1990's-2000's. I have one similar on a 1999 Lil Indian and the kill button was on the shroud. I'm sure that is not a "specific" mini bike engine but it will work.

 

[45t]

Frame looks somewhat like a Cat, but there are a few items that don’t look right for it to be a Cat. Scrub brake, pegs, rear wheel mount Location and wheels all look non cat.

 

[manchester1]

I have no clue what that frame is. We need one of the experts to chime in.

 

[markus]

The bike is made by Nelson manufacturing under the invader name they used for the karts and mini bikes.

Regarding the engine, do you see any loose small wires hanging anywhere? front or rear of the engine. No switch on the shroud usually means a remote kill switch mounting if its an RV type engine. Nothing like that then take off the air cleaner and look real good at wires you do see that and if they are hooked to anything near the throttle control to make sure its not grounded, like say on a mower engine if it goes to Idle position it actually creates a ground to shut the engine off. For testing I would pull any small electrical wires off what they plug into under there, you also may have a low oil float switch inside the engine.....If it is full of oil and you have no spark you want to rule that out as well. Just remember if you pull everything to test and it fires up you need to have a backup plan to shut it down, like a zip tie firmly around the spark plug boot so you can pull it off if it does fire up etc...

The non choke lever, primer bulb carbs like to be started at wide open throttle after bulb is pushed 3-5 times when cold....not ideal for a mini bike application.

If you get no spark after ruling out kill switch, and oil sensor you will have to pull the shroud off and inspect/test/change the ignition coil and flywheel.

If you supply the the engine model number that is supposed to be on the shroud that way its setup can maybe get narrowed down through parts lists etc..

 

[manchester1]

Great info Markus. I thank you.

 

[Generrader]

It didn't come off of a push mower, that's for sure. Every one I've seen runs a vertical shaft, not horizontal.

I know next to nothing with it comes to the Power Sport Tecumseh engines.

Interesting, good to know. The guy sounded like he barely remembered much about it since the mini had been in storage for many years. Makes sense.

 

[Generrader]

The bike is made by Nelson manufacturing under the invader name they used for the karts and mini bikes.

Regarding the engine, do you see any loose small wires hanging anywhere? front or rear of the engine. No switch on the shroud usually means a remote kill switch mounting if its an RV type engine. Nothing like that then take off the air cleaner and look real good at wires you do see that and if they are hooked to anything near the throttle control to make sure its not grounded, like say on a mower engine if it goes to Idle position it actually creates a ground to shut the engine off. For testing I would pull any small electrical wires off what they plug into under there, you also may have a low oil float switch inside the engine.....If it is full of oil and you have no spark you want to rule that out as well. Just remember if you pull everything to test and it fires up you need to have a backup plan to shut it down, like a zip tie firmly around the spark plug boot so you can pull it off if it does fire up etc...

The non choke lever, primer bulb carbs like to be started at wide open throttle after bulb is pushed 3-5 times when cold....not ideal for a mini bike application.

If you get no spark after ruling out kill switch, and oil sensor you will have to pull the shroud off and inspect/test/change the ignition coil and flywheel.

If you supply the the engine model number that is supposed to be on the shroud that way its setup can maybe get narrowed down through parts lists etc..

Thank you so much for taking the time to write all that, I appreciate the help. Don’t see any loose wires - the only wire I do see is a green wire that’s grounded under the throttle assembly and appears to go into the motor. I assume that’s for the ignition right? My Murray mini bike has a similar setup but then there is an additional wire grounded to the same spot that goes up to where I put the key in on the bars. Maybe I need to purchase an on/off switch that wire up and mount to the bars? Or should I not even need that? Also, I’ve had minis with Predator motors where that wire comes out of the motor through a hole in the front of the engine (look at red circle in picture) .. this Tecumseh motor has that hole but nothing coming out of it? Sorry if there’s are dumb questions - I’m a confused amateur. Cleaning carbs is usually about as far as I go with these minis. And on that note, I’ve never had a mini with a primer bulb carb so I have a question about that too. I know with my Gopeds and other equipment with primer bulbs you can feel the gas pumping/pressure changing in the bulb after a few pumps... with this mini I can’t feel a thing, as if it almost doesn’t seem like it’s pumping gas. Should I be able to feel it in the bubble? If so, maybe the carb is clogged?
Anyways, thanks again. I’ll keep trying to narrow down the issue. Bike is full of oil so don’t think it has anything to do with that.

 

[redm18]

Does it have spark? If you pull the spark plug hook it back up and touch the engine with it then pull the cord to start to you see spark?

 

[Generrader]

Does it have spark? If you pull the spark plug hook it back up and touch the engine with it then pull the cord to start to you see spark?

Yes, it has spark. However when I pulled the plug it looked super burnt/fouled so I just went out and bought a new one - the mini still won’t start though.

 

[redm18]

Yes, it has spark. However when I pulled the plug it looked super burnt/fouled so I just went out and bought a new one - the mini still won’t start though.

Dribble a little gas down the spark plug hole and see if it will run.

 

[Generrader]

Dribble a little gas down the spark plug hole and see if it will run.

I ended up taking the air filter off and pouring little in the intake side and got it to start! Thank you! Must just be a dirty carburetor.

Still weird how there is no way to shut off the engine apart from pulling the spark plug cap but I guess it’s not the end of the world.

 

[markus]

Thank you so much for taking the time to write all that, I appreciate the help. Don’t see any loose wires - the only wire I do see is a green wire that’s grounded under the throttle assembly and appears to go into the motor. I assume that’s for the ignition right? My Murray mini bike has a similar setup but then there is an additional wire grounded to the same spot that goes up to where I put the key in on the bars. Maybe I need to purchase an on/off switch that wire up and mount to the bars? Or should I not even need that? Also, I’ve had minis with Predator motors where that wire comes out of the motor through a hole in the front of the engine (look at red circle in picture) .. this Tecumseh motor has that hole but nothing coming out of it? Sorry if there’s are dumb questions - I’m a confused amateur. Cleaning carbs is usually about as far as I go with these minis. And on that note, I’ve never had a mini with a primer bulb carb so I have a question about that too. I know with my Gopeds and other equipment with primer bulbs you can feel the gas pumping/pressure changing in the bulb after a few pumps... with this mini I can’t feel a thing, as if it almost doesn’t seem like it’s pumping gas. Should I be able to feel it in the bubble? If so, maybe the carb is clogged?
Anyways, thanks again. I’ll keep trying to narrow down the issue. Bike is full of oil so don’t think it has anything to do with that.
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Looking at the parts list, that engine does not have the oil sensor option etc.. so thats good (as long as you keep oil in it ) The single wire that is just under the throttle linkage is connected to the coil to ground it out, so all you need to do for a Kill switch is a attach to that via a female spade connector off the kill switch wire of your choice, Like a push button kill switch mounted up on your handlebars etc.

On that style carb the primer does not fill with fuel like on a weedeater type engine, All its doing when you prime it is pushing/forcing a rush of air into the fuel bowl which in turn forces some fuel up through the main and idle jet into the bore of the carb. your carb style on that is a series 8 this website give some insight on how its made and whats going on there for rebuilding/cleaning out: https://outdoorpowerinfo.com/repairs/tecumseh_carb_640017.asp If you have to replace, I would go another route for carburation that has adjustable high/low needles and a manual choke. but don't get ahead of yourself, adjust-ability is nice, but depending on your mechanical skills, and how you ride, may just make it more problematic setup. Not to mention Inexpensive factory style replacement carbs for these are not very reliable out of the box. maybe you can clean it out easy enough to get you going first and you can get a better handle on overall condition of engine, etc.. before you dive into anything else.

Good luck with your project!

 

[Generrader]

Looking at the parts list, that engine does not have the oil sensor option etc.. so thats good (as long as you keep oil in it ) The single wire that is just under the throttle linkage is connected to the coil to ground it out, so all you need to do for a Kill switch is a attach to that via a female spade connector off the kill switch wire of your choice, Like a push button kill switch mounted up on your handlebars etc.

On that style carb the primer does not fill with fuel like on a weedeater type engine, All its doing when you prime it is pushing/forcing a rush of air into the fuel bowl which in turn forces some fuel up through the main and idle jet into the bore of the carb. your carb style on that is a series 8 this website give some insight on how its made and whats going on there for rebuilding/cleaning out: https://outdoorpowerinfo.com/repairs/tecumseh_carb_640017.asp If you have to replace, I would go another route for carburation that has adjustable high/low needles and a manual choke. but don't get ahead of yourself, adjust-ability is nice, but depending on your mechanical skills, and how you ride, may just make it more problematic setup. Not to mention Inexpensive factory style replacement carbs for these are not very reliable out of the box. maybe you can clean it out easy enough to get you going first and you can get a better handle on overall condition of engine, etc.. before you dive into anything else.

Good luck with your project!

thank you again for all your info and help, I’m learning a lot!
I took the carb off and it was the dirtiest/most clogged up carb I’ve ever seen! I cleaned it out and it fired right up today after putting it back on. Only issue was it took off like a rocket ship! I definitely wasn’t prepared like you recommended and almost wrecked it before being able to pull the cap off the spark plug. My Murray tries to take off like this sometimes (nothing to this degree though) and that usually is just because the clutch needs to be lubed again (or if idle is set too high). So I turned the idle way down and sprayed WD-40 behind the top sprocket. I zip-tied an easy “kill-switch” around the plug cap and tried to start it again and it did the same thing. I was stumped and was looking around the mini and it seems like the throttle is stuck at minimum around halfway open? Or it appears to me like that at least (see attached pictures). Don’t know why it doesn’t want to budge lower than the position it’s in now but seems weird. Going to take the cable off tomorrow and mess with it but wanted to hear your thoughts (or anybody else’s input) if possible.
Also, one more thing: I’m having trouble finding an on/off switch setup. I’ve attached pics to help visualize my issue. My Murray has a setup that comes off the ground wire into a “plug” that then goes to the switch. All the ones I’ve found on eBay/amazon only seem the have half the plug and don’t include the other half with the green wire with the connector that i need to put on top of my ground. Either that, or they just have 2 wires with weird ends on them and no “plug.” The closest one I’ve found (see pic) is one that has no plug but has the correct connector I need but also has a seemingly random red wire with a weird end. I probably sound dumb but am not good with electrical. Any help pointing me in the right direction would be greatly appreciated. Ebay seems to have a bigger/better selection, I just can’t seem to find what I need.
I also attached a photo of how dirty the carb was just for kicks.

 

[Steve73]

thank you again for all your info and help, I’m learning a lot!
I took the carb off and it was the dirtiest/most clogged up carb I’ve ever seen! I cleaned it out and it fired right up today after putting it back on. Only issue was it took off like a rocket ship! I definitely wasn’t prepared like you recommended and almost wrecked it before being able to pull the cap off the spark plug. My Murray tries to take off like this sometimes (nothing to this degree though) and that usually is just because the clutch needs to be lubed again (or if idle is set too high). So I turned the idle way down and sprayed WD-40 behind the top sprocket. I zip-tied an easy “kill-switch” around the plug cap and tried to start it again and it did the same thing. I was stumped and was looking around the mini and it seems like the throttle is stuck at minimum around halfway open? Or it appears to me like that at least (see attached pictures). Don’t know why it doesn’t want to budge lower than the position it’s in now but seems weird. Going to take the cable off tomorrow and mess with it but wanted to hear your thoughts (or anybody else’s input) if possible.
Also, one more thing: I’m having trouble finding an on/off switch setup. I’ve attached pics to help visualize my issue. My Murray has a setup that comes off the ground wire into a “plug” that then goes to the switch. All the ones I’ve found on eBay/amazon only seem the have half the plug and don’t include the other half with the green wire with the connector that i need to put on top of my ground. Either that, or they just have 2 wires with weird ends on them and no “plug.” The closest one I’ve found (see pic) is one that has no plug but has the correct connector I need but also has a seemingly random red wire with a weird end. I probably sound dumb but am not good with electrical. Any help pointing me in the right direction would be greatly appreciated. Ebay seems to have a bigger/better selection, I just can’t seem to find what I need.
I also attached a photo of how dirty the carb was just for kicks.
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That float! OMG

 

[Generrader]

That float! OMG

Had to scrub it with a wire brush for a long time to get all that off lol. Float bowl looked similar, covered in green gunk. People think that if they empty the gas tank before storing they’re ok but in reality you need to let the mini bike completely run out of gas while running.

 

[Bigjake]

Looks like the kill switch with the green and red will work for you just have to change the end on the red one with a flat and hook it on the the connector where the green wire comes out of your engine then take the green one from the switch and ground it on the engine somewhere

Another thing I don't like the angle that throttle cable goes in to the holder looks like it would bind easy see if you have enough cable to make it go straight in the holder just a little slop will help
I'm clueless on your linkage maybe look for governor adjustment that's the first thing they mess with and screw up most of the time

 

[minibikin']

Disconnect the cable from the linkage. Try starting it with the rear wheel off the ground. Perhaps the linkage was pulled too tight when the cable was installed and it isnt returning all the way to idle?

 

[Generrader]

Disconnect the cable from the linkage. Try starting it with the rear wheel off the ground. Perhaps the linkage was pulled too tight when the cable was installed and it isnt returning all the way to idle?

That’s exactly what it was. Thank you.
And just wanted to say thanks to everybody that helped me out! Got her starting right up and running perfectly now. Clocked at 33mph on the speed trap by my house. Tons of fun.