Engine Bogs in High Alpha

[Notorious B.E.N.]

I have a DA 60 on a Pro Flow can in an Extreme Flight Edge. I've noticed that the engine starts to bog when I go into high alpha. This includes upright harriers and rolling harriers. It also bogs on inverted downlines (45 degree) and when I roll upright, it returns to normal.

Any ideas of what I can try?

Transition is fine with no hesitation and very little midrange burble when upright.

 

[yakken]

Tunning or it needs a metering plate mod

 

[Notorious B.E.N.]

I have added a nipple to the diaphragm plate and I have a line running to a pill bottle in the fuse. Not mine but same idea:
http://www.GiantScaleNews.com/forums/attachment.php?attachmentid=133437&d=1225051504


Is the metering plate mod like this?
http://www.GiantScaleNews.com/forums/uploads/6/2/9/a569887-210-Mod%231.JPG

 

[49dimes]

That's what I did to my DA 120. Works great but the 60 is a rear mount carb. what you did should work fine. Also Might want to increase the spring tension a bit under the diaphragm. Just a "gentle" stretch is all it takes.

 

[Terryscustom]

When I had problems with my 176 the pill bottle did nothing, I did what Dave Sullivan suggested (same as Dimes is showing) and it worked perfectly.

Transition is fine with no hesitation and very little midrange burble when upright.

However in high alfa you are not suffering from cowl pressure effects so I would first check your tuning on the low end. Also verify your header length with Dave on that setup. It is likely that. You should have zero mid range burble.

 

[Notorious B.E.N.]

When I had problems with my 176 the pill bottle did nothing, I did what Dave Sullivan suggested (same as Dimes is showing) and it worked perfectly.


However in high alfa you are not suffering from cowl pressure effects so I would first check your tuning on the low end. Also verify your header length with Dave on that setup. It is likely that. You should have zero mid range burble.

Should I try setting the low richer or leaner first?

Also, what's a good source on how to make the plates to go on the carb for holding the fuel tubing?

 

[Dirt Doctor]

DA sells a plate with a nipple on it for around $8 bucks.

 

[Terryscustom]

Should I try setting the low richer or leaner first?
Also, what's a good source on how to make the plates to go on the carb for holding the fuel tubing?

No guessing.....tune it.
http://giantscalenews.com/threads/basic-engine-tuning.2806/

 

[Notorious B.E.N.]

OK, I was actually referencing that at the field Sunday. Will give it another go and start with the low and get that steady 15-20 second idle first.

 

[Notorious B.E.N.]

I played with the needles yesterday and the motor sounds great for the most part and is still having problems in high alpha. I did notice on the last flight yesterday that it sounds like it's being starved for fuel occasionally for just a second even in straight and level. So I'm going to pull the fuel tank and inspect and also inspect the screen in the carb.

Any other places I should check?

If I don't find anything in the fuel tank or screen I may buy a Dubro tank to assemble and throw in there just in case there's something up with my water bottle tank.