I have a MX7-180C. Seems that the front of the starter housing (nose of the bendix casting) is rubbing on the inside of my cowling. Question is: what can be done about it. Since the starter isn't movable and the cowl position is also fixed what are my options? I figured I'd repair the cowl with some fiberglass but that won't stop the rubbing. If fact, adding the extra fabric and resin will increase contact pressure.
I am not really familiar with the MX7-180C installation.... But a friend of mine owned a Husky, and realized there was something different about how the bottom of his spinner was getting too close to his cowling. The lower isolation mounts were shot....
I second Karl's thought on isolation mounts. Could even be as bad as a broken/bent engine mount. If this is a new problem with an airplane you've had for a while I would have an A&P look it over very carefully before your next flight!
If the airplane is new to you and it came that way, I'd still have it checked before the next flight, though it might be possible someone has done something wrong on a cowl replacement?
Mine is the same, except I'm a 235 with new Lord mounts and nothing's wrong with my engine mount. The cowl was simply "fitted" too far aft. I thouht about bonding a thin piece of stainless steel to the lower cowl, but ended up grinding a little off of the nose of the starter. If you don't do something, eventually it will wear a hole in the cowling.
When installing cowls, I get more clearance up there if I install both cowls loosely with the screws at firewall / bootcowl, then reach fwd and lift nose of cowlings, and now tighten all the screws holding top and bottom cowls. By doing this, it can make a big difference in the clearances at the front end?
If your fitting the cowl on a 540, shove it up as high as it can possibly go. Then you might have enough clearence for the two top front spark plug wires. At least on an IO, not sure about the O.
you can push up all you want but the #1 and #2 top spark plug wires are still pinched by the top cowling (O-540)
i have replaced the leads on #1 twice now. i currently have a lead with the 90 degree metal elbow on the end. this needed some carefull bending, so that now it just touches the cowl- instead of being smashed into it. we'll see how this works.
UP-M5 wrote:you can push up all you want but the #1 and #2 top spark plug wires are still pinched by the top cowling (O-540)
i have replaced the leads on #1 twice now. i currently have a lead with the 90 degree metal elbow on the end. this needed some carefull bending, so that now it just touches the cowl- instead of being smashed into it. we'll see how this works.
I bent a two pieces of .040 aluminum in an angle and attached it to the cylinder heads. I then rolled two pieces of stainless steel and bonded them to the top cowl with B2 fuel tank sealer to give the aluminum something to rub on. I haven't pulled the cap on my new harness to see, but I don't think the leads can be individually replaced on that big single drive mag that I have. So far that has worked. Too bad Maule just didn't make the cowling a half of an inch taller there.
I had this problem with my 2001 M-7 rubbing and couldn't change it. So I took a piece anti-chaff tape (teflon) and suck it to the in side of the cowl. Then bought a square piece felt with sticky backing at home depot. I cut a piece to fit the front round part of the knob that sticks out and it worked great. Never even changed it in the 4yrs I owned it and it stoped the rubbing.
Last edited by Wayne on Thu Mar 20, 2008 5:31 am, edited 1 time in total.
TomD wrote:I have done a "on field survey" of M5-235's and see a little spider web in the cowl above the #1 plug in quite a few of them
I had (have) the same problem.
My solution was to go with a Unison (now Autolite ) plug which is about 3/4" shorter than the comparable Champion plug.
Problem solved.
TD
I didn't know that. I've got Champion fine wires, and if you know what those things cost, you know why I don't want to change them. On the massives, the Unison plugs are every bit as good as the Champions, they just look better and cost less. I wonder if the Unison fine wires are shorter too? The fine wires run smoother, peak happens at a leaner mix, and my hot start issues are gone with them. I want to stick with fine wires.
Question is: what can be done about it. Since the starter isn't movable and the cowl position is also fixed what are my options? I figured I'd repair the cowl with some fiberglass but that won't stop the rubbing. If fact, adding the extra fabric and resin will increase contact pressure.
