jpf5911

I purchased a Magnum .91 four stroke for my 4*60.

My engine has a rear needle vavle / choke adjustment which I like for safety reasons. However, with all that hardward in the back of the engine, I have had to mount it slightly more forward than optimal (about 1/8 inch). Also, I noticed that I will have to cut some holes in the cheeks of the plane to accomodate the needle valve.

Is this just something to deal with or should I try to swap the engine for the one with the adjustment valves in the front, or is there some other way to address this problem?

Please, no Magnum bashing as I have had good luck with their 2 strokes and they are way more affordable than the other choices.

Thanks,

JPF

digger.10

Having a little hole in the plane is a lot better than having a big hole in your finger... 1/8 inch forward of ideal mounting position is no big deal, with a .91 chances are you are going to have to ballast the rear anyhow. Moving the battery towards the tail will help.

FHHuber

The .91 class 4-stroke is too good a match for the 4*60. Don't worry about the bit of inconvenience getting at the needle, you won't have to adjust it often. 4-stroke needle settings are more stable than 2-stroke. (and 2-strokes don't need tweaking very often... once the correct fuel and prop are being used.)

Try a 14X6 on the 91 4-stroke once its broken in. (13X6 for break-in flying). You should like the results.

mahoo

If your cut out for the needle valve extends into or past the reinforcing lite ply. Find the laser cut piece that came out of the cheek plate and install a portion of this additional lite ply to reinforce around the needle cut out.

Mitch

jpf5911

Good point. I think the needle valve sits low enough that I can poke a whole in the thin, inner part of the cheek, rather than the doubled outer portion.

We'll see!!

JPF

dr_wogz

My Feedback: (3)

I had a Super Tiger .91 on mine.

Some advice that was forwarded to me:

Beef up the landing gear. The stock gear is a little flimsy, especially with teh bigger engine up front.

Add bigger diameter wheels as well, larger prop means less ground clearance. using a 3.5" dia wheel will add a bit..

And, if you can, go for a larger fuel tank. A 16oz just fits!

In the two crashes i had (one minor, one .. one that rendered it to the back of teh shop, to one day repair..) the engine mounts were rather weak. They were the first things to break. While this is a favourable thing, i do wonder if I was on the 'edge of teh envelope' of teh mounts..

Don't forget to post a picture when it's flying!!