Noob with engine problem
 

Peakmodels 26cc, engine starts, runs at a fast idle,moving throttle fully open or closed makes no diff to engine rpm.Throttle butterfly works,tryed larger fuel hose no diff.This is my first venture in gas so any ideas before I beat it with my Hammer and go go back to glow.

RE: Noob with engine problem
 

I have two of these engines, they run great! This sounds like a weak ignition battery, make sure it's charged, only use 4.8v, there is no need for 6v.

Try this:

Get Pennzoil, run it at 32:1 all the time.

Do check the timing, here's my way:
The easy no math timing.

Cut a strip of paper 1/4" x 5".

Rap the paper around the prop drive, back by the crankcase where the magnet is. Overlap the paper then cut with a #11 blade cut though both layers of the paper.

Now you have a piece of paper the exact circumference of the prop drive.

Cut it in half, take one of the halves and cut that in half again, take that and cut it in half also. Now cut it so it's in 1/3 and 2/3 pieces.

The 2/3 piece is how much before TDC the engine should fire, (30*).

Now find TDC by removing the spark plug, then sticking something in the hole, a pencil works fine. Move the crankshaft until the piston. is at the top of the cylinder, you'll find that about 5* either side of the TDC it doesn't feel like the piston is moving. Wiggle the crank back and forth until you can find the center of this piston not moving zone, that's TDC.

Now with a marker make a line across the edge of the prop drive onto the crankcase, it doesn't matter where, just that it's easy to see.

Now turn the prop drive clockwise a distance equal to the 2/3 piece of paper.

Plug the ignition into a 4.8v battery, and turn it on.

Now with the two screws loosened move the sensor off the magnet until you hear the ignition pop.

Tighten the screws for the sensor down, then confirm that the timing is still set that 2/3 piece of paper before the TDC mark.

You may have to lengthen one of the grooves in the sensor mount to get the timing correct.


1.Start the engine, set the throttle so the engine is going 3500 rpm.

2.With the engine running I turn the "L" needle in, it is always the needle that is closest to the engine, when the engine speeds up to 4000 rpm I adjust the throttle to bring it back to 3500 rpm. You keep repeating this step until your engine doesn't speed up anymore when you turn the "L" needle in.

3.Turn the "L" needle out 3/16th of a turn.

4.Open the "H" needle 2 turns out, open the throttle all the way open. Now slowly turn the "H" needle in the engine will increase in rpms. Turn the needle about 1/16 at a time, when you get no more increase in rpm the "H" is set properly.

5.Set you idle speed with your throttle trims, it's best to take the idle stop screw completely out, you should have it so the idle is correct with the trim in the middle, and the low trim kills the engine.

6.With the engine running at the idle speed that you fly at you should now be able to snap the throttle open and the engine quickly speed up. If it just dies, turn the "L" needle out 1/16th of a turn, repeat this step until is quickly speeds up. If when you snap the throttle open it stumbles then speeds up turn the "L" needle in 1/16th of a turn until it cleanly and quickly speeds up.

7.Close the hole or notch up in the choke plate, I'll post a picture of what I mean, I do it with soldiering the hole close, some use glue or a bolt.

After you modify the choke plate the way to start the engine is:
a. Close choke completely.
b. Open throttle half way.
c. Flip engine with ignition on until the engine coughs.
d. Take choke fully off.
e. Set throttle just above idle, flip until it starts, usually 3 to 5 flips.

RE: Noob with engine problem
 

A very good post.

Karol

RE: Noob with engine problem
 

Wouldn't it be eaiser to use a degree wheel and a pointer.I no your way way will work,but sounds complicated for a guy just getting into gas.
What ever works.
BCCHI

RE: Noob with engine problem
 

Do you think he would have a degree wheel being a newbee?

RE: Noob with engine problem
 

I made one by printing it out with my printer and pasting it to a piece of light ply. I like the C-H one the best

It works as well as my professional one

RE: Noob with engine problem
 

Well thanks to you W8ye he's got more than one now.

Karol

RE: Noob with engine problem
 

Thanks for help guys,I reset timing but didn't do much. One of the guys at my club has the same engine nib so we swapped out the carb and hello we have throttle response,still a little rough but I think I just need to follow Soarich's tuning tips and we should be all go.That is if it ever stops raining,so much for our summer.

RE: Noob with engine problem
 

Hi we had a guy in our club arrive at the field with the carb on backwards on his chinese engine so the pulse hole from the crankcase was not lined up with the carb so no pulse no pump no gas, check yours was ok and put back your old carb in the same position as the one you have on with the engine running, it may have been that.

RE: Noob with engine problem
 

Just my 2 cents worth. Blocked exhausts. Have a few problems with hornets, etc building a nest in the outlets, have had ppl spend a lot of time trying to find a engine wont rev problem..
Get the same problem with whipper snippers and chain saws..