flywheel replacement 912uls hard starting

[Slyfox]

I'm to the place that I need to replace my sprag clutch, when I start my engine cold it will crank and then slip out (neutral) let up on starter and it reengages. I hit the starter again and it will generally start right up. The other day I started the airplane did the same thing and had a hard time wanting to start. I thought to myself, what if it's flooded. I turned off the choke and went full throttle, kept cranking without a problem and fired right up, of course put the throttle to idle, ran real nice. I'm thinking flooded.

I called lockwood for the parts and was told since I now have the newer soft start modules I don't need the updated flywheel. The new flywheel would give an additional 7 degrees retard. I would like to know what others think about this. engine is a 2008

now why my engine is a little hard to start. I may need to just use half choke, I do preheat. thoughts. also thinking of backing off the idle mixture a half turn from 1.5 out.

[Av8r3400]

Steve, do you have the left-right-both-start switch or individual ignition toggles?

[Slyfox]

I have individual mag switches and a start switch

[Av8r3400]

After a few "kickback" events early on, this is the start procedure I have adopted to save my sprag and lightweight starter:


1. With ignitions *OFF* - Crank engine with auxiliary fuel pump and enrichener engaged sufficient for conditions.
2. With ignitions *OFF* - Continue cranking, release enrichener from right hand and reach over and turn on ignitions.
3. If engine does not light off, turn off ignitions then stop cranking, repeat from the top.
4. If engine starts proceed to warm up procedures.


Summary: I always try to get the engine turning at max RPM on the starter before turning ignitions off or on. I want the spinning inertia to help the engine start rather than trying to power through an ignition event with the starter. I do this weather the engine is hot or cold.

My engine is a low compression (but slightly higher than stock 80 hp) Zipper big bore.

[Slyfox]

I've tried similar, it seems as soon as the mags are on it kind of stops the motor. than the sprag slips out. so I'm sure that is most of my problem. My concern right now is I have the 912uls high compression, I've read many people saying that installing the updated flywheel and the soft start modules is a must. I currently have the soft start modules that replaced the green strip modules that did go bad because of no go at cold startup. I had severe problems with my right carb flooding out because of a bad seat. I have since replaced that carb and things are working great, that gave me some awful kickbacks. thus damaging the sprag clutch. Lockwood advised me against replacing the flywheel cus they say it doesn't do much. I don't want to NOT replace the flywheel since I'm right there. So I'm actually asking of that is a right thing to do and keep my original fly wheel. the updated flywheel will give an additional 7 degrees retard on startup. I totally tired of what I've been through the last year with this engine. right now after I do get it started it's the best I've ever had it run. I also put the bigger cross over pipe between the manifolds and now It runs with NO miss throughout the rpm ranges, it will idle way down to a very low rpm and be super smooth, love it. My engine is a 2008, I have a little over 800 hrs on it. the gear box was also rebuilt this last summer.

[Dusty]

Have you considered an aftermarket replacement ignition module?Some of these have programmable start parameters,