exhaust

[Tony]

Ok, I just got in from a ride on my mini bike. I was going down the road and i heard a noise, it sounded like the chain poped off. (It didn't but i think it hit a mount support.) Anyways i started it up to continue my ride when I noticed I was going really slow, probly about jogging speed. I turned off the engine and the chain was a bit looser (but still doing its job.) Then it wouldnt start. I had to hold the throttle down a bit to get it started. And now it is idling way slower and I did not mess with the carb. Any ideas on what could of happened?

 

[Tony]

Tecumseh engines are low performance no matter how you slice them. In my opinion, the math involved to get what you want will give you little bang for the buck.
Is this a reed valve engine or piston ported?

reed this is the engine https://surpluscenter.com/item.asp?UID=2009042117540743&item=28-1477&catname=engines They have some good prices on engines, chains, sprockets, pulleys, ect.

 

[Affair_driven]

Link not working:

 

[Tony]

you have to click continue to this website on IE. when it comes up to the error page.

 

[Affair_driven]

Still n/g.
What is model number of engine?

 

[Tony]

techumseh ah 600. i googled it and didnt find much.

 

[Kenny_McCormic]

Backpressure=BS
blowing an engine from no exhaust=BS

Engines dont run right and damage valves, seize, etc. without an exhaust pipe or with a straight pipe because people neglect to rejet the carb.

I can pull a McCullough Mac 110 off the shelf right now and fire it up. Muffler bolt threads are stripped out so it has no muffler, but every now and then it has a screwdriver taken to the screw labeled H. Fun to stand back while somebody uses it and watch through the exhaust port as the fuel demands change and the flame color goes from orange to blue.

 

[motor_head]

if you strait pipe it make SHURE you adjust the carb to run richer or the lack of backpressure will make it run lean which is bad on any engine but on 2-strokes its even worse
running a 2-stroke lean means it won't get the proper lubrication BAD

 

[modelengineer]

blowing an engine from no exhaust=BS

You can damage the exhaust valve from cold air coming in contact with the extremely hot valve once you shut down the engine though. It can make the valve stem brittle. I don't know if that counts as 'blowing the engine', but it wouldn't work after the valve breaks.

Completely agree with the backpressure thing though.

 

[motor_head]

it's a 2-stroke no valves

 

[modelengineer]

Then you can damage the piston. I've seen it happen.

 

[pmat]

i had a 2 stroke gas scooter that i ran for 2 years with the muffler off and it ran great until the mount on the engine to the scooter literally snapped. haha the motor was running on the ground bouncing around and the kill swich wire was off