A question for those with Fox engine experience

Lustrox was still being sold by Fox in the eighties. What used to crack me up was watching folks ruin their ball bearing/ringed engines with its use. It was meant to hasten the break-in of bushed/lapped piston engines.

Anyone remember the factory recommendation to help 55 Chevy V-8 engines hasten their break-in by having dealers pour Bon Ami down the carb of a running engine?

I saw this repeated by an American Motors dealership in the early sixties when AMC introduced their then new seven main bearing six cylinder engines. The rings were too hard, allegedly, and needed help seating. Betcha the cylinder walls took the brunt of the beating.

Ed Cregger

Now I'm beginning to see the light....

Thanks Paul.

Good flying, desmobob

That business about long breakins applied to the old Fox engines that had an iron piston in a steel sleeve. Look in your .40 exhaust ports and I'll bet you's see an aluminum piston with a ring in it. For those who don't believe me, take a look at the parts list on the Flightline Solutions web site. It shows a piston ring for the .40 BB.

You can fly the ringed and the ABC engines right out of the box. I've done it many times. I still am using a Fox .50 (ringed aluminum piston) that I bought around 20 yrs ago. It's still going strong. I will say this: they do like a little extra castor in the fuel.

All my Fox engines came with tilt-down "mufflers." Duke used to run an exchange program if you wanted a tilt-up. Dunno about now.

Cheers,

CR

give me your address and I will send you a Tilt-up muffler # 90246 still in the package,,,no charge, only the snipped-for-privacy@webtv.net

I know this is a response to a really old post, cause I recently just got back into reading this group again, but I feel I might have something to add anyway, so here goes.

Pay particular attention to the projects and modifications menus, to the left. If you have a two needle valve carb, read this one,

real carefully, and if there is any problem with the midrange running rich (usually the problem) use the procedure on the low speed needle. Caution: remove a very, very, very, (one more time ) very small amount of metal at a time, then put it back in and test it. Removing too much will result in you ordering a new needle. DAMHIKT !

If people can not get their engine running right, and it is in good condition, there are a few things that are important. It all comes down to believing what is in the owner's manual, in the long run. Read it twice, and take every *little* thing as gospel.

They must have castor oil. If you can't get it straight castor, a blend is OK, but if you can find a bottle of racing castor oil, it does not hurt to add about 4 ounces or so per gallon of fuel.

If you have adjusted the needles and the engine has a rough midrange, but a good idle and high speed, follow the needle adjustment (sanding and filing) procedure. I got two engines for 20 bucks, cause the guy that got them said he could never get them to run. Now, there is no adjusting, except a click or two on the high speed, then I go fly with the knowledge that the engine will not stall while I am flying. The big problem before adjustment was that it would stall when it went from idle to full throttle. That usually show it has a rich midrange.

If you get it is going to full throttle well, except sometimes after a very long idle, consider using a Fox idle bar glow plug. It might help. The only other glow plug I ever got to work well was an OS glow plug.

Don't break them in too rich, because they will never get up to operating temperature. When they start to get too hot, richen it up just a little, by going to the 4 cycle sound, then lean it out until it just holds a two cycle again. After it cools, lean it down to max RPM, then quickly lean 2-4 clicks, if it starts to slow, at all. Seconds count.

Good luck. They really are a great engine, once you understand them, and like the others have said, bullet proof, too.

I got my Fox .50's to run great by using Perry (Varsane) pressure pumps. (the red ones). Another guy here in Amarillo Texas (elevation 3650 AMSL) was able to get his to run consistently by not opening the throttle barrel all of the way, and adjusting the high speed needle valve accordingly. A too large venturi has been mentioned more than once as the culprit causing poor fuel draw in the Fox engines. I believe it is .375 or greater. Another club member cut a new carb gasket with a smaller opening which functioned as a restrictor plate. His ran fine too.

I got my Fox .50's to run great by using Perry (Varsane) pressure pumps. (the red ones). Another guy here in Amarillo Texas (elevation 3650 AMSL) was able to get his to run consistently by not opening the throttle barrel all of the way, and adjusting the high speed needle valve accordingly. A too large venturi has been mentioned more than once as the culprit causing poor fuel draw in the Fox engines. I believe it is .375 or greater. Another club member cut a new carb gasket with a smaller opening which functioned as a restrictor plate. His ran fine too.

Thanks very much for the tips... I appreciate your taking the time to send them along!

Good flying, desmobob