New engine - not as easy as it looks !!!!

[andys]

Started breaking in my new engine. All went well, did it as per engine instructions, although I heated it up first with a heatgun. Then ran it a little and started leaning it out as the factory setting were very rich.

A few days passed, went to run it again today (couldn't pre heat it this time) and it just kept cutting out on the box when I gave it the gas. In the end I went back to stock settings, got it warmed up and started the leaning process again.

What did I do wrong, is it just the cold weather and a new engine ?

Engine is a Tecnopower and pipe combo. Went like stink when I got it running again.

Very tempted to get a Surestart engine pre heater now....

[dave g]

you cant just start a cold engine up and give it gas or 90% of the time it will cut out when you nail it.

if it starts and idles ok,then let it idle for 20-30 seconds to get a bit of heat into it.

[andys]

Cheers Dave.

I was only running it on the box when it was cutting out, it would only idle with the throttle trim opened up a bit, I was then trying to just increase the revs a bit to warm it up on the box, but it just kept cutting out when I tried to increase the revs.

I seem to think it jut was too cold, as it was a cold day and after re starting it a few times and resetting the needles / getting some temperature into it, it ran ok.

Just hard I guess to get heat into a new engine when you are outside and it's freezing !

[dave g]

put a sock or some tinfoil around the head to keep a bit of heat in.
when running an engine in i never run them too rich,i run them in on about 90% race tune.

running and engine far too rich puts a lot of stress on the conrod and bushing as your effectivly hydrolocking the engine,its bad enough with the extra pinch,plus you cant get temp into the engine.

just lean the lsn a little a time until it idles ok.

[andys]

Cheers Dave.

Engine break in is a bloody minefield. Read so much on it - it hurts. The manual said to run it rich, make it 4 stroke etc. I did this a bit, but did lean it out when I started doing low speed runs with it. Had around 8 tanks through it now, building it up, but the pinch is just silly when it's cold. Starter box really struggles !

To that end i've ordered a SureStart pre heater, otherwise I think i'd be struggling to get it running now its dropping colder.