GAB Version CHEAP.0 Tecumseh OHH50 172cc 5HP

[bob58o]

This is what I am trying to recreate
http://oldmowerparts.com/Tecumseh-730130-exhaust-adapter-kit-P3999326.aspx
Cheaper to buy it, then buy the drill bit and tap.
Not sure it fits 100%???
BUT I like adding tools to my collection.
AND want to learn to make stuff myself.

 

[bob58o]

I like this one too!!! I know this one will fit.
http://www.ebay.com/itm/TECUMSEH-5-...166513?hash=item3d08d4c3b1:g:Ag0AAOSwDNdV4jjx

 

[bob58o]

Also the angle of the exhaust port vs the location of the carb is an issue.

This is going to be tricky unless my welding improves greatly.

So much for CHEAP.0 ;0

 

[bob58o]

Stock muffler.

 

[bob58o]

Holy metal batman!

 

[bob58o]

Holes need to be bigger.
They were off maybe 0.020".
A 17/64 and some back and forth may do it.

 

[bob58o]

Looking exhaust flangish?

Some people weld onto regular washers to make easy flanges.

 

[chancer]

Grind off the Galvanizing compound before welding. It makes noxious fumes, and it will make it easier to weld.
Also on those taps When I thread pipe (I know opposite thing) I will go 1 or 2 turns then back out 1/2 a turn. It keeps from creating 1 big curly shaving, that will get in the newly cut thread and screw up the thread.

 

[bob58o]

I used a socket and ratchet.
Like 1/4 turn in, 1/8 out.
The hex socket kept slipping on the square end of the tap.
It wasn't easy.

Next time I'll use the impact wrench.

 

[Poboy kartman]

I used a socket and ratchet.
Like 1/4 turn in, 1/8 out.
The hex socket kept slipping on the square end of the tap.
It wasn't easy.

Next time I'll use the impact wrench.

You will break the tap unless you are extremely careful.

 

[chancer]

That kit should have come with a "T" handle. Or use a crescent wrench. They are designed to be done by hand not with power tools.

 

[bob58o]

Flange attempt #2 was closer, but I am not happy with it.

The holes were off and I should have tried to slot them instead of going for a bigger diameter.
NOTE TO SELF: SMALL CENTERPUNCH HOLES - BECAUSES MAKING 0.020" ADJUSMENTS WHEN THE CENTERPUNCH MARK IS 0.045" IS DIFFICULT!!!!!!!!!

Flanged hex bolts will work if holes are perfect I think.

In reality, there is about zero room for error. Seems like I need perfectly placed holes and socket cap screws.

With a larger diameter hole, I can bolt it on BUT I don't like the fit. The bolt hole is close to the center bore. I tried using flanged bolts, but the flange prevents me from threading the pipe in. Or the pipe prevents me from getting the bolts in. I'm going to get socket cap screws, but think my holes might be too big to get a good seal with these????

socket cap screw head 1/4 - 20 is 0.375"
Hex Head 1/4 -20 is 0.505" across the widest part
Flanged is even wider I believe.

I forgot how big I had to drill to BUT I DON'T LIKE IT!!! I have another square washer to play with.

Going to try some different screws, but I already pulled the trigger on multiple back up plans.

Bought this first.
http://www.ebay.com/itm/Tecumseh-5-...886402?hash=item3f68204ac2:g:~iEAAOSwqBJXXKD8

It is 10.5" and I would need to cut it down to 8". The end would still be only an inch or so away and blowing straight into the rear fender. I don't like it, but this is the only exhaust that I am 99% sure fits the engine (still doesn't fit the bike).


This is the one I bought second.
http://www.ebay.com/itm/TECUMSEH-5-...166513?hash=item3d08d4c3b1:g:Ag0AAOSwDNdV4jjx

I am 85% sure it fits.
This is what I want to use!!!!!!
See how it is welded inside and out. The outside weld stops for bolt head.

I will put a 45* 3/4" Female NPT Elbow on this.
A few inches of pipe.
Another 45* elbow.
Some pipe.
Another 45
Then the final length of Pipe
Then optional muffler.

It will dip down from the exhaust port, curve above the carb, then turn and go out under the seat.
THE WAY A MINI BIKE EXHAUST SHOULD!!!



At least I got some new tools (which I like just as much as engines and go karts!!)
Too bad I don't know how to properly use them(or even have a need for some of these tools).

 

[bob58o]

This engine will be a learning tool/toy for me.

What you think about this new air box?
There used to be much more plastic (7 sq inches?) and only two penny sized holes.

Now just one big hole.

 

[bob58o]

Vs Before

 

[bob58o]

And there was 1/2" wall the air had to climb over to get to the second little hole.

 

[bob58o]

Think this is free flowing enough?

Or does it need speed holes in the side plastic, so air can have a straight shot to the carb??

 

[bob58o]

Ok new basic exhaust design.
It won't be so close to the carb, but will still pass above it.
The flange I got is shorter.
These pipes come on 1/2" increments so adjustments are easy.

What you think?
23.5 - 24" long.
3 x 45 degree fittings.
Too long?

 

[bob58o]

Lots of options.

 

[Poboy kartman]

Bob....center punches help...step drills help...(the ones that have a smaller flute in the center) ....or....just start with smaller bits and work your way up....At the very least...you need an 1/8" pilot hole to drill that large a hole..
and a drill press with a clamp would be nice...(but not necessary) .

I like the airbox...it's almost got as large a hole in it as your wallet.

 

[bob58o]

This actually bolts on!