It sounds like your are flooding your Fox 35. You should understand from the posts on breaking your Fox in that it is not a buy-and-fly engine. It needs to be properly broken in first. I get the impression you have it mounted in your Nobler. If so, this is not good. Best to make a test stand and get it working and broken in before you put it in an airplane.

Take a look at this thread. http://www.rcuniverse.com/forum/m_5708436/tm.htm

Is the engine still mounted in an airplane? It is much easier to break engines in on a test stand...

How does the engine feel when you flip the prop? Same as before? If not, any ideas why?

Possibility - fuel line clogged with some kinda gunk, or filter is clogged (you are using one, right?) Or if no filter, some dirt might be blocking the needle valve/spraybar unit. If it is that, pull the needle out and flush the spraybar. When doing that block the spraybar's needle side to make sure you the jets inside the venturii aren't blocked.

Another possibility, but you sound like you may have checked for it, could be a hole in the fuel line. Silicone tubing gets pinholes very easily, and they aren't always easy to spot.

And a rare possibility for new equipment - if the tank is metal and has brass tubing, a tube inside the tank may have split along its length...

Backplate on tight?

Luck! a good Fox 35 is a long-lasting pleasure...

yes i have it mounted in my nobler but i made a stand that holds the whole plane up side down so the engine is up right, yes i have a filter it's clean, fuel lines good, tested it and the filter,it has a plastic gas tank it's good, spray bars fine, lets put it this way it's getting gas in the engine, because some times i have nitro run out of the muffler! to rich when that happens! but i even tried to crank it with only two truns out and then one turn out! i know that's way to lean right? but it still would not start[&o] and yes the back plate is on nice and tight.

oh and it feels a little easyer to turn over after about the first day of having it i think it was a little tight to start with but it feels fine now, still wont start[sm=confused.gif]

I would remove the muffler during breakin.

would that help on starting?

Wonder if your needlevalve is not seating properly. Try screwing it all the way in and put a piece of tubing on and try to blow through. If you can, there is at least part of your problem. If it will shut off completely, make sure the engine is dry and put a little fuel in the exhaust with the piston up. Turn it over once or twice and put the battery on. A hard flip, and it should fire and run for a second or two. Get it to do that consistantly, then open the needle one turn and try again. Your problem is that your engine, for some reason, is flooding. So what I am advising is designed to keep the crankcase from getting flooded. If you can keep it from flooding you should be able to start it.

PT-19, I think I might have an idea worth investigation. I have had this problem before with some RC models, but only a couple times.

First, you say you are using a "plastic" tank, i.e. an RC tank. That in itself is fine. Now, are you using muffler pressure? [:-] You also say the engine is in your model which is turned upside down. [X(]

If so, you just might be getting a big blow back as the pressure/fill tube is submerged in the fuel and the fuel weight is trying to fill your muffler. When you are flipping the prop, the piston is somewhat like a pump and the pressure line compresses, then blow-back can be bring fuel into the muffler which sucks back into the cylinder. Doesn't take much to flood a tight new engine at this point. Now when you do get a pop or so, it simply blows the fire out in the plug OR it just does a lean start and you have the NV too much closed to allow fuel draw, so instant flame out.
I would -- as you were advised -- remove that muffler for at least an 1/2 hour of initial running.
I have never had a Fox on a Fox N/V that did not need 4-6 turns open. As suggested above use the blow-through test. In addition, I have never owned a Fox that would not run, even if only very poorly because of the next item coming up.

This happened back in the 1960-62 era, and could have happened again. Duke had some assemblers (Back then all Foxes were assembled by hand) that were less than attentive to their work. Many Foxes were shipped with the Sleeve in backwards. That did not do Fox any good in the market place. I discovered it when a buddy had a new Fox that would start but only run like it was rich, and flame out if he tried to lean it out. I looked into the exhaust, and something did not seem proper. Off with the head, and twisted the sleeve to line up the ports properly, and the darndest thing happened. It ran like advertised.
In the next 10 years I found people with Foxes that would not run. All same problem.

Icing on the cake: About 7-8 years ago I bought a Fox 36 on eBay. Looked brand new. Set it in a stand and fired it up. It had a muffler on it. Same old thing. I laughed, jerked off the head, rotated the sleeve and it still flies a CL model this very day.

So you keep pecking around and we will find out how to make that Fox run. BTW, look in the venturi and be sure it wasn't one that Duke marketed for PUSHER operation, with a different timed crankshaft. [X(]

It'll help clearing floods and the engine will run cooler without it.

well after all this time i finally got that fox to run! three and a half turns out ant about six flips of the the prop and bam!, and once it started i turned the needle valve out some more, and i've got about three tanks run thru it, now that i've got the engine running now i've got to worry about flying it![X(] after i get it brock in of course.

broke, sorry

Congratulations. It's always a good feeling to master engine starting.

yeah i know, and the whole thing is i have a bunch of cox control line engines and never had a problem at all starting them, but the good thing is i got it to start so i'm happy