hi, i just bought a used asp .91 engine. it seems to have good compression but it is a real bear to start. i could only start it with the throttle just above idle, if i opened it any farther it would spray fuel out of the carb. i`m using a starter to turn it over.i got it started it & it ran good, good idle,transition & top end, but when i idled it down too low it stalled. it took 5 mins to restart it & it was fairly warm when it stalled out. is it normal to have to start it at a low idle,my 40`s will start at idle, full throttle or anywhere in between.how many turns should i i start with on the needle as a baseline ? it was set at about 3 1/2 turns out when i got it but i turned it in at least 1 full turn to get it running & i don`t want to run it lean! i`ve never had anything bigger than a 40 size engine . thanks alot conk

if a motor dont start first look at fuel supply then plug then all the rest it's for sure not because it's a asp or os !!

These engines are usually easy to start. Try the main needle at about 1 - 1/2 turns. Mine run about 1 - 1/8th turn when leaned out.

Sounds as though its cold weather where you are at? Wait until it gets warmer?

You might try a OS glow plug?.

Jim

i`ve got it running. w8ye your right. i had to turn the needle in alot. now the engine starts easily but won`t rev up , it`s stalls out when i try to advance the throttle. it also surges at idle a little bit. i noticed a hissing noise coming from the front bearing as i turned it over by hand.i see a bubble coming out of the front every once in a while when i turn it over. i guess you don`t get much for $20. the engine look like new & has good compression, but i`m thinking the carb is shot. i wonder how much a carb is & if i can even get one? thanks for all your help!!

You may still need a glow plug?

The other thing is that you may have the big needle in too far. Try easing it out a little. If the idle is a little rich and you set the high spped to where it runs right at low speed, it will go lean when you try to speed the engine up.

Also in this cold weather, alcohol engines don't do so well. Let it warm up some too.

Jim

Hello Congster!

Back in '93 I bought a ASP .61 and installed it in a C.G. Super Chipmunk. Several times I tried to fly the plane , but most of the times it flamed out and resulted in a dead stick landing. Never really investigated why the engine did'nt want to run properly so it ended up a hangar queen untill 2000. My son started to fly pretty well and insisted on taking the Chipmunk with the troublesome ASP. The plug burned out on the first flight and I changed it to a O.S. # 8 . What a difference, it runs like clockwork and is very dependable. ( Although I wished it was a .91 in the plane for more vertical performance.)
Moral of the story: Try a OS # 8 and feel the difference, I'll bet it will run better. Also check the carburetor fit, I replaced the O-Ring where it seats into the crankcase.

thanks buchtes i`ll do that ! i have it running alot better now. i have a test stand i use to break in small motors but the 91 won`t fit in it so i cut a hole in the 3/4 plywood that i mounted everything on & bolted the 91 down. the problem was that the mount for the smaller engines is about 1 1/2 inches taller than where the 91 mounted. so guess what?the fuel tank is 1 1/2 inches higher than the carb on the 91. not good!! i mounted the tank on the 3/4 plywood also, it runs good now. the idle is a little rough so i think i`ll try the different plug that buchtes suggested. thanks for all your help!! conk

I have one of the ASP 91 red heads and it runs great. Usually starts with one or two backflips. It has a lot of compression and will bite you occasionally if you handstart in the conventional forward direction. Also, some people have found it necessary to run it with a head gasket, especially if they like to run nitro in their fuel. In fact, mine came with one included in the box. I never installed it as I rarely run more than %5.

Greg's right!! These engines don't like nitro at all! There made in China and were designed to run on no nitro fuel. Too high a compression ratio. The added head gasket lowers it enough to run 5%, but any higher and it just doesn't like it one bit!
Suptter

w8ye what do u mean alcohol engines ? i`m running 15% nitro in it . it runs good except for a kinda rough idle. it has a 12 x 6 prop on it , someone told me to put a 14x 5,6 or 7 ? is this right? thanks conk

12 x 6 is kinda small for a .91. I usually run a 14 x 6 on mine, 15 or 16 x 6 with a pipe. I think 15% is a lot of nitro. The ASP's have high compression, and don't need all that nitro. It'll probably be happier with 5% or less. If you blow plugs, run hot, or hear that sizzle--use less nitro.

rsieminski took the words out of my mouth.

Jim

i`ll get some new fuel. it seems to run good on the bench , but maybe not in the air. thanks guys conk

Does anyone know what the proper timing and valve setting is for
an ASP four stroke.61

Get the Rocker arm assembly off the engine.

Put the engine on Top Dead Center.

Raise the exhaust cam follower up out of the way.

The Dot on the cam should align with the cam followers and push rods.

Re-assemble.

Adjust the valves .002" to .004"

Complete valve setting instructions are available if you need them?

Jim

Thanks I'll try that .
Youve been a great help.