inverted mount 4strokes ??
 

hello everbody...i'm thinking about a ucando 3d 60 with a 91 4stroke, but my friend told my that a 4stroke wont run reliable mounted upside down (saito's)?? anybody got anything on this ? maybe this is a saito thing and not so much for an o.s.:D

RE: inverted mount 4strokes ??
 

I have a Saito .56, a Magnun .91 and had a OS .91 4-stroke all inverted and have yet to have a flame-out. No on-board glow either. Sorry, but your friend doesn't know what he's saying. I'm sure there will be many more posts saying the same. This is a topic thats been rehashed many times here.

RE: inverted mount 4strokes ??
 

The majority of my Saito's are mounted upside down, everything from .82 to 1.50. They run just as good inverted as upright. I have a U-Can-Do .46 with inverted Saito .82 and it runs perfect. I don't foresee any problem with yours.

RE: inverted mount 4strokes ??
 

This is absolute hogwash. All my 4 - strokes ( OS, YS & Saito ) work fine.

RE: inverted mount 4strokes ??
 

Well there is my U-Can-Do with an inverted OS 90, Runs and flies beautifully.

Ed S

RE: inverted mount 4strokes ??
 

Ditto, Ditto, Ditto, and Ditto. Methinks your friend knowest not what he speaketh about.

RE: inverted mount 4strokes ??
 

G'day Mate,
The only time you will have trouble with an inverted motor, 4stroke or 2 stroke, is when your fuel tank is too high or too low, it MUST, be set so that the tank centre-line is level with or no more than 1/4"(6 mm) to 3/8" (10mm), below the fuel nipple, NOT above.

RE: inverted mount 4strokes ??
 

I agree with all of the previous comments - BUT- the key to using an inverted motor is to have it set up properly.

This includes, having the fuel tank mounted properly,
- tuning the engine properly,
- using the proper 4 stroke glow plug and
- using the correct fuel (10-15%)

The big problem with inverted engines is that the fuel runs to the top (bottom) of the cylinder head and cools the glow plug so things don't work properly.

This is caused by too much fuel (tank mounting & tuning), the wrong fuel (low nitro) or poor plugs.

A quick fix is to install an onboard glow system - that will cure the 'other mistakes'. But I like to KISS (Keep It Simple - Stupid).

Correct the real problem(s) and you will not need the onboard system.

RE: inverted mount 4strokes ??
 

I think its an improper set up thing! Your 4 stroke will be just a s happy inverted (and look better on your plane) as right side up. I think most folks problems on inverted engines is tank location.

RE: inverted mount 4strokes ??
 

I'll disagree on the tank location. All my 4 strokes are inverted and I have never altered the tank location. I feel the key is to make sure your low end needle is properly, after a proper break in of course.

RE: inverted mount 4strokes ??
 

I agree with you RC-Sport. I have had several arf's with inverted four-strokes and always put the tank where its suppose to go. Never ever paid attention to tank/carb height. And I ALWAYS use a OS F-plug.

RE: inverted mount 4strokes ??
 

I have to agree with Dan and Rc Sport. I've never moved a tank from the stock position and never had any problems with an inverted 4 stroke. Now 2 strokes are a different animal.

RE: inverted mount 4strokes ??
 

I agree, 4 strokes run fine inverted. However, 2 strokes do too if you get them set right.