Custom Exhaust

[holmsey2012]

Has anyone tried to use a custom exhaust off something like a 250cc dirt bike on their robin 244cc motor? I have an 86 marathon and I've heard an 88 carb and exhaust are about all you can do to increase power besides a major redesign. Just curious. Winters are long up here and I'm looking to try a few things before spring hits.

[DOOmsman]

I am not sure about this but we can talk about it.
It wold seem that a 2stroke pipe would run hot,
it sends a pulse back to the engine that is stronger
than a mufflers back pressure.
?????????

[1989Marathon]

Originally Posted by DOOmsman

I am not sure about this but we can talk about it.
It wold seem that a 2stroke pipe would run hot,
it sends a pulse back to the engine that is stronger
than a mufflers back pressure.
?????????

The 244cc is a 2-stroke.

[pachanga90]

The trick is to find a 2-stroke pipe that is from a similar weight machine,but a lower rpm range to match up with the 244 motor(most 2-strokes turn high rpm,carts don't,even modified).I was going to try a YZ125 pipe that I had,but never got around to it.Hope this helps.

[Morgan44]

Somebody needs to try this. Hmmmmm.

[pachanga90]

Bigger carb would help,as would increasing timing-advance,but they set the timing at 0 so they will run in both directions.The timing being advanced would increase power and rpm quite a bit.If someone could find a way to retard timing for reverse only,it would be huge!!

[Morgan44]

I wouldn't have the know how to attemt the timing thing. I do know the fellow above with the super charger attempted that on a very similiar motor with no luck. I have to say, if he couldn't do it, I don't know that it can happen. I would love go see an exhaust change that would make a difference though.

[redcloud]

I have a 91 marathon and would never want to buy an OEM muffler at the prices I have seen. I did do some searching on this forum a while back and found a post that a guy had taken his muffler that was shot to a tractor dealer and they modified a muffler from a lawn mower and it worked great. Would have to do a search to find again but that is what I would try if I ever need one, jeeper's it would be cheaper to muffler a dragster than a 91 marathon.

[bildobildo]

I have a 90 marathon and a 92 suzuki rm 250 I finished rebuilding two years ago I might have an extra fmf pipe and silencer. I will have to check however not sure what good it will do me because the transaxle input shaft took a dump on me today. but i will look anyhow and see if it will fit with and then start it to see how it sounds. but probably wont be able to tell any if performance changes.