I've got one of these, and it does fly!!!!

problem is, engine keeps going dead....has anyone had to change the fuel tank level to match the spray bar??

Thanks

Mac

no, my 82 running fine

going dead, too lean, bad plug, air leak?

Spitfire,

you on 4s?

Mac

is your fuel tank buffered from vibration , if not the air bubbles will allow you to run and run well for about 5 to 10 mins , then wala , they will shut you down every time

another thing is it could be over heating, turn the HS needle out a little and see if that helps, if not most likely fuel foaming.

what fuel are you running?

Originally Posted by commrad

another thing is it could be over heating, turn the HS needle out a little and see if that helps, if not most likely fuel foaming.

what fuel are you running?

yep, a lean run causes overheating, sagging and then stop. Richen that sucker.

4s????? How come you asked that? No,Saito 82

Sorry 4 stroke....

Originally Posted by The Spitfire

yep, a lean run causes overheating, sagging and then stop. Richen that sucker.

even if it's rich on the ground, air flow could be the culprit. can you post a pic of you install? I had a plane once that looked like it had good airflow and ran very cool on the ground (had it 1k rpm below peak) and in the air it would over heat in less than 2-3 minutes and die. had some very weird aerodynamics in the air that stopped it from cooling.

Originally Posted by commrad

even if it's rich on the ground, air flow could be the culprit. can you post a pic of you install? I had a plane once that looked like it had good airflow and ran very cool on the ground (had it 1k rpm below peak) and in the air it would over heat in less than 2-3 minutes and die. had some very weird aerodynamics in the air that stopped it from cooling.

Yep, good point. I forgot to say that i cut out a serious of slots underneath to aid the air flow

that's how mine was that was overheating in the air. does the head stick out of the cowl? the head of an engine is really the only thing that has to be cooled. are all 3 vents in the chin cowl open? the 2 upper ones can actually be closed off. 1 thing you could do is to use a thin sheet of balsa and build a false bottom on the cowl that is closed at the front (glued directly to the cowl and raised about a 1/4 inch or so at the rear). this will create a rather large gain in airflow.

just looked at the openings in the front, the lower hole isn't scale so scratch closing the top 2. another thing you could do is to make the chin cowl functional which would be effective.

after looking at my P51 I ended up going with a larger engine so the head would stick out of the cowl and I have never had a heat related issue . the valve cover is even with the cowl in the rear and about 1/4 inch above the cowl in the front. to be honest just looking at mine you would swear it would fry after a few minutes but it does great. I've seen some that look like they would cool the crap out of an engine and after a few minutes of running they boil off fuel.

try running with out the cowl on if you feel it may be heat related and see what happens.

[QUOTE=commrad]can you post a pic of you install? QUOTE]

Lets see it

I was assuming that you have the air in and an outlet cut for air out ?

I've lowered the tank by about 30mm, botoom of the tank was higher than the spray bar....

Pics attached, please excuse the cowl damage, that was the last deadstick!![/IMG]

ok, let me ask another question, did the engine look like that when you installed it? all that baked on castor looks like it's been hot. my OS 10 has over 20 hours on it and still doesn't have the baked on castor, even my nearly 20 year old OS 40 fp doesn't have it. my 5 hour run time Magnum four stroke has some on the exhaust pipe.

looks like you may have a considerably higher inlet than exhaust on the airflow which is a bad thing.

just my misguided opinion.

I took the liberty to borrow your pic. I think you would do better with the gray areas covered, I see you opened up the chin cowl. again just my opinion.

you could try contacting KentuckyColonelon on here, he's a pretty knowledgeable guy and if I remember correctly he's flown his share of CMP's

btw an easy way to close off the air before you do a permanent block off install would be to use some duct tape over the holes and try it with the expectation that it will die, if it helps then maybe look at a more permanent fix.

here's a pic of all the cooling I have on p51. the hole for the valve cover is tear drop shaped to allow glow plug access.