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Engine basics => Engine set up tips => Topic started by: Chris Belcher on January 31, 2017, 08:41:27 AM

Title: Stalker 46 issue
Post by: Chris Belcher on January 31, 2017, 08:41:27 AM
I have a profile Cardinal that has the universal mount from Brodak so i have been trying different engines out. ST 46, LA 46, and others all run the way they are supposed to. Yesterday i mounted a Stalker 46 and had an issue with what sounds like it going dead rich when you point the nose down. Lap times were even so I'm pretty sure tank height is correct, prop was a XOAR 11 x 6 and Rev 11.5 x 5, both worked pretty well and lap times were 5.2 to 5.4  The engine breaks everywhere like it is supposed to EXCEPT like on down leg of outside squares and when you hit the turn to inverted on the reverse WO. As soon as you hit down it just seems to go really rich, like a burp but not a burp. It responds back pretty quickly and only seems to do it on the first turn...after that is seem OK. I tried uniflow with press, uniflow no press and vented, all about the same.

Set up is:
Stalker 46 SE (new ones from Tom Dixon) not sure if they are the same as the ones i had back inthe 90s. It is a baffle piston but I thought my old ones were iron piston..don't remember really
Thunderbolt RC long plug
RSM 4.5 oz uniflow tank
XOAR 11 x 6 prop
stock needle valve
stock venturi...not sure what size it is...yet, will measure tonite.


Title: Re: Stalker 46 issue
Post by: Walter Hicks on January 31, 2017, 12:57:22 PM
There were some comments in the Stalker 46 Engine Review regarding this. I spoke to Tom Dixon recently regarding this I dont think it is a problem just
annoying until you get used to it according to the review and Tom.
Title: Re: Stalker 46 issue
Post by: Chris Belcher on January 31, 2017, 02:36:47 PM
Where might this review be? Wouldn't mind reading that. I wonder if it was on profiles only or both inverted and side mounted...
Title: Re: Stalker 46 issue
Post by: Chris Belcher on January 31, 2017, 02:39:23 PM
Found it...yep he mentions it too in the exact same places as I had...interesting.
Title: Re: Stalker 46 issue
Post by: Steve Helmick on January 31, 2017, 04:02:20 PM
Fuel used? That might make a difference. Some Stalker users around here used 80/18, no nitro, all Klotz. Others used "YS 20/20" (i.e., 20% nitro) because they needed more power.  D>K Steve
Title: Re:
Post by: Manuel Cortes on January 31, 2017, 11:15:13 PM
Hi all.

Some years ago I usted a 1995 Stalker 46 (plain bearing version, ABC,BTW) and performed flawlesly without any burp ir similar. I used 11x6 wood, and 5% nitro. 22% oil (50-50). Launch revs 8600. Was a delight, same character as a good ringed ST 46, and lasts forever.

Kind regards.

Manuel

Enviado desde mi Y635-L01 mediante Tapatalk

Title: Re: Stalker 46 issue
Post by: Chris Belcher on February 01, 2017, 08:53:33 AM
I KNEW I was forgetting something in the set up part...fuel of course...of some importance DOH!
I actually was thinking this may have been the issue all along, I was using Powermaster 10/22. I don't have any all synthetic or low castor content fuel or I would have used it as i have read these like very little castor. Since i first posted I have gotten PMs about this engine and this issue. I put the engine in another plane in inverted mount and no burps, just the sweet stalker run i remember from the 90s.  8)
Title: Re: Stalker 46 issue
Post by: Manuel Cortes on February 02, 2017, 01:44:17 AM
Hi again.
I recommend you to check the backplate sealing. In the ninetees I had a nightmare with a Merco 35 who ran perfect vertical but burped when SideWinder position....after several work, it had a problem with the backplate joint. Once replaced, was perfect again........just in case......

The presure lost was minimal, but caused the indicated problem.

Kind regards.

Manuel.
Title: Re: Stalker 46 issue
Post by: Chris Belcher on February 02, 2017, 03:11:27 PM
Interesting...If I remember correctly the Stalkers have the "screw in" back plate where the case is threaded female and the backplate threaded male, with little cut outs to get your tool in to pry/twist off, and an O ring or some kind of gasket back there. I will look tonite.
Title: Re: Re: Stalker 46 issue
Post by: Manuel Cortes on February 02, 2017, 11:54:03 PM
Interesting...If I remember correctly the Stalkers have the "screw in" back plate where the case is threaded female and the backplate threaded male, with little cut outs to get your tool in to pry/twist off, and an O ring or some kind of gasket back there. I will look tonite.
Yes, is antes uncommon failure un that configuration, but never mind, and easy to check.

Kind regards.

Enviado desde mi Y635-L01 mediante Tapatalk