bumpman

My Feedback: (23)

I have a ST .25 that I cant find any info on.I dont know when it was manufactured or what it is, X series ,ABC, or ? IT has a highly polished head and carb top,allmost show quality.No ring.flat piston.Only says made in Italy by Super Tigre,stamped 25 on one side and the "S" on other.

Bax

My Feedback: (11)

You have one of the old SuperTigre S-.25 egnines. It was likely manufactured in the late 80's to early 90's.

Will Glenn

I have a SuperTigre .25 exactly like this. I looked and I couldnt find anything about it either. It came on an older Great Planes pt-20 that I saw at the local hobby shop when I first started out in the hobby. I purchased the plane for 80 bucks and didnt notice the that it had a SuperTigre .25 until i got it home. When I was working on the weight distribution of the plane, I pulled the old battery pack out and the date was 1999.

Unowat2

Hello:
I was also interested to read your article on the Super Tigre 25. I have the same but with a faded purple head.
I am having difficulty getting it to run reliably, either tick-over or full speed.
Really my question is does it need a rebuild as I feel the compression is not good.

Will Glenn

re"> Your case sounds exactly like mine. I havent achieved getting it to get to run reliably. I really need it run one more flyin season. Have any suggestions?

Unowat2

Hi Will:
Regarding age of engine I can confirm I purchased it secondhand, from a shop during the middle to late 80's. It has not been used much since. Possibly because it would not run reliably.
I have bench tested it with different nitro content fuels ( 5%, 10%, 15% ) and glo plugs. I have also checked the carburetor spray-bar is positioned correctly.
On my most recent test I was using 5% nitro and OS No 8 plug.
I am wondering if the compression is lower than it should be it is not drawing in the fuel reliably. This in turn would cause me to over richen the mixture to compensate and the engine cannot cope with that amount of fuel.
Also I notice when running there is fuel visible in the carb intake as if it is not drawing properly. I am confident it has the correct carb fitted but is quite large for a 25 when compared to a OSFP 25.
I am hoping this can open a discussion as I feel the engine is to good to be scrapped.

Regards Colin.

Will Glenn

re"> I agree it shouldn't be scrapped. When I was trying to learn to fly last summer, my dad and I got mine to run, but the only way we got it to run was to rev the engine the highest we could and adjust the needle valve until it revved the highest. I did kind of guess that it would've been manufactured around the 80s-90s period.

Bax

My Feedback: (11)

It may just be that the carb's not correctly set. Please see the carb-setting post at the top of this forum.

I the engine has a lot of time on it, has had an overheat, or has had debris run through it, then the piston/liner fit will be bad, with lowered compression the result. Idle is the first thing to go when the compression starts to go. Top-end is usually not affected right away.

Idle is also an indicator of a badly-set carb.

Figure on up to 5 hours of running or so for the engine to become fully broken-in, if it's not abused.

Will Glenn

Thanks Bax. That helps a lot. I will definately use that forum when I make adjustments.