This engine ran great mounted up now that i inverted it,it will quit when i quickly come off full throttle.i have lowered my tank and still have the problem,it will also quit at full throttle.Ive tried three different plugs and two fuels with the same results.Finlay i left my glow igniter on the plug and no problems so an onboard glow driver may be an option,but i don't understand why it quits at full throttle,idle i can see with fuel building up but not full throttle.......any thoughts?????

You need to angle the engine to one side or the other so excess glow fuel will not puddle around the glow plug hole

Also check the tank pressure connection on the muffler. Oil should not be able to puddle there as well.

Have you leaned the idle screw a lot? It may be restricting the fuel flow even at hi throttle. If you can't richen the hi speed it may be your problem.

On board is not going to solve your problem. Need to find the problem first and fix it. Try readjusting the whole thing again and check it by pinching off the fuel line at an idle speed or remove it and let the engine quit and listen to the rpms. This will tell you exactly where you stand with this thing

I run several engines inverted with lowered tanks and no problems.

Ive done all the tuning i can stand with this engine.at full throttle pinch the line and the rpms go up a few hundred rpm and on the low end the rpm goes up a little then dies.the tank has been lowered enough and i have no leaks.I'm running 10% cool power and tomorrow i will try 15% omega and some different plugs and i will rotate the engine a few degrees to help prevent pooling.if all this doesn't work I'm going to play soccer with it.

Try an idle bar plug and see what happens if you haven't already.

Ernie

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There you go. I've seen this work before under just such circumstances. That is why I carry as many different types of plugs with me as I can. It is worth a try and it may work. May not, but what are you out of? Nothing.

Hi Ed, well I used to carry a lot of different glow plugs, but someone usually needs to "borrow" one, and now I wonder where they all went...

Ernie

First, try a recommended fuel for the engine type "ABC" according to the directions. The Tower is a tight ABC engine and needs caster. Morgan recommends omega for ABC and ABN engines.

i tried it again with 15% omega.it ran like it did when it was mounted head up with 10% coll power,i could not get it to quit.can anyone explain the difference in fuel?why will it run inverted on this fuel and not the other?thank you to all who answered this thread

Well, like I said in previous posts, the directions tell you it will run the best with castor or a castor/synthetic blend and Omega has castor in it, which will help cool a tight "ABC" engine. You also stepped up the nitro a little to, but mine runs no different with 15% than 10% other than a couple hundred rpm on the top end. The Tower and Morgan directions both state that Omega is the proper fuel (blend) to run in the .75 since it is a "ABC" engine..

My friend's Tower 75 engine is deadsticking a lot. It seems that if he gives it the throttle fast, it hits the glow plug with a rich slug of fuel and quits. It will idle beautifully and the top end is slightly rich of top rpm. So what gives.... any ideas? The engine is upright and different glow plugs have been tried to no avail. Fuel is 10% Omega type I believe.

Thanks!

Ernie

Ernie,
Try leaning out the bottom end. Mine runs awesome, and starts with one backward snap of the spinner. Is the engine in question brand new. They are very tight when new. I ran mine for an hour on the stand. I just cracked the ninth gallon yesterday. My engine does nothing but make people rub there forehead. They cannot believe how well it runs. It pulls the Shoestring over 100mph easily. What prop are you running.

MOTORMAN, I think the prop is a 13x6, and the engine is fairly new, but should be well broken in by now.

We'll go back to leaning out the bottom end more IF it will take it next time he brings that engine.

Thanks,

Ernie

Ernie
when my engine was mounted up it ran great but in the beginning when it was new i had problems with it running at full throttle. the fix was to remove the remote needle,seal all fuel fittings,back plate,carb,and i cut a small piece of fuel tubbing and placed it over the high speed needle.i did not do all this on my own i read about this fix in earlier threads,but it worked.

Hi Jawbuy, if it were leaking air it wouldn't want to shut off either, right?

Thanks,

Ernie

The throttle is an air throttle not a fuel throttle. we do not have a gas pump like a car. A fast throttle opening gives it lots of air so it must have a bit of fuel hanging around. Try a richer low end.

ERNIE
I listed a lot of things i did to get the engine to run right and while I'm not sure witch one fixed my problem one of the things i did got it to work,maybe i had a bad remote needle but instead of fixing one thing at a time like i probably should of i did all the fixes at one time that i read about on rcu.now i could be wrong (and i probably am)but i would think a small air leak would cause the engine to lean out and quit.i understand that an air leak would keep the engine from quiting but maybe an air leak was happening only at full throttle( i don't know)but I'm trying to help.
Anyway i flew that plane today for the first time, its a harrier 46 and it was great everything worked perfectly,this is my second harrier 46 with this engine but its the first time i had it inverted

Wow, the Tower 75 engine on a Harrier 46 plane! I bet that is a LOT of fun. Way to go. This is what it is all about ..... :-)

Thanks for your suggestions and help. They are much appreciated.

Ernie

The 75 is a great engine for a 40 size plane and will run with the best of them. It is a very tight engine when new and will require a little breakin time but oh boy when this thing lets go you will be pleased. Just use a little JB Weld to hold the muffler together at the joints. I like the 12.5X6 prop the best but it will pull the 13X6 very well. The engine is a little sensitive on the needles but with the tuned muffler you can expect that (not as much back pressure as a quiter muffler) and the needles will need to be set properly or it will let you know. My 75 would run rich but would gurgle on transition. I tried a smaller prop on the 75 but it didn't like it so I use the 12X6 to 13X6 prop and it is very happy. I think the small prop required more fuel than the carb could deliver (too many rpms).