pywackit

Guys, I've got a Magnum .61 4 stroke that I've been using for quite some time now and haven't had any problems with her at all. One of the old timers noticed how much build up was on the muffler and said that that wasn't right. The build up looks like cooked residue, all brown and such. He seemed to think I'm running my engine to lean so it's getting hot. I thought this was normal but he told me his 15 year old 4 stroke doesn't have any build up at all and he's never had any to even wipe off. I know I can clean it off but just haven't done it yet.
Oh yeah....I'm using that 15% Omega fuel.

DaveB

Sounds like castor oil residue to me. Try cleaning the muffler using the crock-pot anti-freeze method.

DaveB

cruzomatic

My Feedback: (17)

Go to the store and pick up some Dawn Power Dissolver. It's awesome. Spray, wait a few minutes then brush with a light wire brush and wipe off clean. You'll thank me later.

http://www.homemadesimple.com/sites/...issolver.shtml

bruce88123

Yep, you're burning castor and he's probably using synthetic. Makes a difference. I wouldn't change a thing or worry about cleaning either.

pywackit

That sounds like great news! I've got it cleaned up already.....can I run synthetic in mine, just what part is synthetic anyway?

Now I'm guessing here but my engine runs hot most of the time and I was wondering if it's just running to lean or maybe the prop size isn't a good one for her. I've got a 11-8 on her now but will put back the 12-6 and see if that makes a difference. I've noticed this engine isn't really that powerful for it's size and have thought about putting a .70 4-stroke on her....I know that'll have more then enough power. I wouldn't have to run full power with that, wonder if you can switch the carb linkage around on a .70 4-stroke...maybe I just want a bigger engine...LOL!

Thanks for the help guys!

bruce88123

It's the oil. You can run completely castor, completely synthetic or any combination thereof. Castor protects the engine just a bit better. Follow your engine manufacturers recomendations as to oil content. It should be in the manual.
Typical 4c fuel mix is 65% methanol, 15% nitro, 20% oil. Variations on those basic numbers.

danny31292

You may have the wrong prop but remember the 2c and 4c engines don't have the same power for the same size. Four strokes do run hot and the mufflers do burn right after they are run. Also if you really want to get the caster off use the antifreeze method as other have suggested.