2013 - Turbine powered hydrostatic launch craft

[landuse]

Have you seen these links

Tecumseh carb cleanup, servicing and troubleshooting
http://www.kichline.com/chuck/fixit/mowers/tcarb/tcarb.html
http://www.smallenginesuppliers.com...cumseh_L-Head_Engines_Service_Information.pdf
http://www.smallenginesuppliers.com...cumseh/Tecumseh-basic-service-information.pdf

 

[sp_1989]

Wow, good info!

 

[sp_1989]

I ordered a carb kit, so maybe I'll be able to get it running smooth again. Thanks again landuse, the service info book had good carb information.

 

[landuse]

I ordered a carb kit, so maybe I'll be able to get it running smooth again. Thanks again landuse, the service info book had good carb information.

No problem. All these links can be found in the Helpful Links Sticky. Lots of good info there

 

[sp_1989]

Little Welder

Little Welder
(I know it's not a welding helmet and she doesn't weld.)

 

[sp_1989]

Drivetrain

A few pics of the drivetrain. I don't have a good way to cut slots to adjust the motor, so I got a belt that was close and used a few washers to adjust the motor. I ended up with the chain and belt just right. I know they'll both stretch over time, but for now it will work.

I'm currently waiting on the carb kit to arrive so I'm working on the hydrostat linkage. I think I'll put the lever in front of the steering wheel. I need to make some detents or something so it will stay where I put it. Should be interesting.

I think the throttle linkage will work ok. I didn't have a single cable long enough, so I used two together. The pic shows where they are connected.

 

[landuse]

The setup looks good so far. Your chain might be slightly too tight, but I am not too sure from the pics

 

[sp_1989]

Carb Rebuild

Well, I finally got the carb kit and spent part of Saturday rebuilding it. The carb itself is in good shape and some of the parts definitely needed replacing. It still leaked when I put it on, but I messed around with it a bit and it doesn't leak now. I tried running it a bit and it still has some issues. I'll work on it today some more.

Meanwhile I'm trying to finish up the hydrostat linkage.

Also on the to-do list, but not essential, is to connect to a quieter muffler. I found a piece of pipe that fits, so that's a start. Pretty loud with a straight pipe!

 

[sp_1989]

Going Nutty!!

That carb still leaks. I think I don't like Tecumseh carbs. I haven't had many problems with briggs carbs. I've rebuilt the carb from my Scout and my truck without any problems, but this one is not cooperating.

I'm wondering if the float is sticking. It seems to leak gas out the air inlet, so it's probably overflowing the bowl and running out the jets.

I need to check the float again. I didn't see any holes and there was no gas inside the float. It did actually float in a container of gasoline. I set the float level per directions, using an 11/64ths bit.


Any ideas?

 

[sp_1989]

Shift lever and muffler

Got the shift lever installed with linkage to hydrostat tranny. I don't have any detent positions, so you just have to feel for the center neutral position.

Also mounted a big muffler off the donor Deere. It's slightly quieter.

 

[sp_1989]

Atmospheric vent hole

Ok, after much Googling, I found a little vent hole I did not see earlier. I found it after wire brushing even more on the body of the carb. I used a little wire and cleaned it out.

I set up a little test stand to check the float. I put gas in the funnel and let it run into the carb. I watched as the "bowl" level came up and the float shut off the fuel. I let it sit for at least five minutes without any overflowing. I emptied it and refilled it several more times and it worked each time. Then I put the real bowl on and used the same setup. It worked well without any overflow or leaking. I THINK maybe I'm ready to try it in real life.

But I have a few other issues I'd like to take care of. One is the fuel line itself is pretty crappy, so I need to get a new one. The other is the routing of the fuel line. As you can see in the pic, it goes right against the engine. I think when it gets warmed up it vapor-locks. Since this is a former snow blower engine, I'm sure it isn't a problem in the winter. I'd like to route the fuel line in a cooler location, but I would need a 90 deg elbow on the fuel inlet. That may be a future adjustment.

 

[sp_1989]

It RUNS

Woo hoo! It runs!

That little bitty hole in the carb must have been the reason the carb kept leaking. Amazing how such a small hole can make that much difference.

I put the carb back on and put on a new fuel line, fuel shut off valve and fuel filter. When I added gas and opened the valve, I could see the gas in the clear fuel line and it didn't spill out the carb. I didn't change the location of the fuel line, so after I run it a while i'll see if it vapor locks or not.

I started it with just choke and no priming. I opened the choke and adjusted the mixture screws so now it runs pretty smooth.

Then I tried the driving test. It moved! I went forward and backward a little in the shop, then backed out of the shop to the grass. Once I hit the grass, it didn't have enough torque to move. I don't know if the hydrostat needs to have more air bled out of it or if it just doesn't have the torque to run at this high of a gear ratio. The original mower was geared down quite a bit, so that might be part of it.

 

[chris_the_poser]

Congrats on getting the carb problem sorted out.

 

[sp_1989]

Done!

Thanks.

Whew! What a project.

There's still room for improvement.

http://www.youtube.com/watch?v=mehWzDdyY6M

 

[DaiSan76]

Very cool. Do you have a foot throttle there to adjust your speed, or just that hydrostatic drive handle?

 

[sp_1989]

I have the foot throttle, but I am using a lever for now since you don't really need to adjust the engine speed much.

 

[sp_1989]

The problem with the Hydrostat Drive

Well, I gave it a shot. I tried the best I could to get the hydrostat drive to work for my go-kart. It would move it if I was on flat concrete, but it just didn't have much output torque. It would not go at all in the grass.

I also had problems keeping the driver sprocket on. I welded a #40 chain sprocket on the little original gear with the proper splines. I then drilled a hole and tapped it for a set screw. The problem was that that little gear was so hard I couldn't drill it very cleanly and tapping it just didn't end up right. I stripped the threads with a set screw and that was all she wrote for the sprocket.

I wanted it all to work, but I just couldn't get it done.

 

[sp_1989]

Last minute changes

Ok, so I bought a torque converter and finally got it installed. I re-connected the gas pedal to the throttle and I think everything is working.

Of course, nothing can be easy on this project. I had to drill and tap a hole in the end of the engine shaft. That was not as bad as I thought it was going to be. I also had to get a chain half-link to make the proper chain tension.

I took it for a spin this morning and then again this afternoon in the 95+ degree heat. It works pretty good.

I have now officially finished it for the second time!


http://youtu.be/uCpSbw1usN0

 

[sp_1989]

Before and After

Here's the before and after pictures.

We took it for a spin and the little inspector liked it and had lots of fun riding.

This contest was a good motivator to get this project done.

 

[landuse]

This contest was a good motivator to get this project done.

Thats what we want to hear!! Great job