Mentor 140 Problem

[Robert Schofield]

Lance,
The engine is a 140.
I have had the engine about a year. The pipe is one piece  5 oz. The header was included so I thought they would match. I didn't mess with the pump as I "adjusted" the pump on one of the first Hano 61's and never did get it readjusted. Had to send it back to the sevice center and they set it back in.
Is counter clockwise lower pressure on the pump screw?
Thanks for the advice and insight. 
Bob Schofield
  ----- Original Message ----- 
  From: Lance Van Nostrand 
  To: discussion at nsrca.org 
  Sent: Sunday, May 08, 2005 9:53 PM
  Subject: Re: Mentor 140 Problem


  Bob,
  You say you are running the 140?  or is it the 170?  Which Mintor aluminum pipe, the sectional one at 3.5 oz or the old style at 5 oz?  They have different baffle positions and the tuning lengths are different.  Mintor began supplying a different length header when they released the new lighter pipe, so there's a possibility you have a mismatch. I'm very familiar with the 170 but less so with the 140, in as much as they have exchangeable parts.  
    You want to prop the engine to run about 8000-8200, so the advice of others to use more prop is good.  If you want some more details visit my website at www.aeroslave.com under 3m Mintor engine tips and tricks.  I have some advice there.  You probably will have to lower the pump pressure 1/2 turn because I did when testing the engine with CoolPower.  Feel free to contact me off list with more details and I'm sure we can resolve this.  When set up right the Mintor (170 at least) has the most linear 2 stroke carb out there.  
  --Lance

    ----- Original Message ----- 
    From: Robert Schofield 
    To: discussion at nsrca.org 
    Sent: Sunday, May 08, 2005 6:15 PM
    Subject: Mentor 140 Problem


    I need advice. I have been trying to dial in a Mentor 140 for 6 or 7 months. I have about 7 or 8 gallons of fuel thru it. It took forever to get it to run half way right but it finally started to work. I have it in a test plane because I still don't trust it. After break-in I tried to fly it but it would surge at any low power setting. The people I got it from sent me a new pump and carb. It will now idle well but mid-rang is so rich it will 4 stroke. I was told to lengthen the pipe, which I did. It was set at 1/2 in. between the header and front of the pipe. By the way the pipe is the aluminum pipe from Mentor. The header is a 30mm. rise from Mentor. 
    I leaned the low end and set the pipe at 3/4 in. spacing. I also leaned the top end. I have tried lean and rich on both top and bottom. It always runs very rich mid-range. I am using 15 % Cool Power. 17x8N APC. RPM top is 8800. I richened it to 8400, 8500, 8600. Idle is very good and reliable. When I pull verticle, that is when it leans out and runs like it should, however blowing the top of the box at 80 mph ain't cool.    
    I was told to lower the pump pressure, which I have not done yet. 
    I have run YS,OS,Supertiger, Hano's for 15 years, but this is the most flustrating thing I have ever seen.
    The power is scary, however I would like to have throttle control instead if a "parked and gone" switch. 
    HELP
    Bob Schofield    
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