Thread Tools
Aug 23, 2010, 04:19 PM
Registered User
Thread OP
Help!

Frustation with my O.S. .35 FP C/L engine


...........................I have a Top Flite Tutor(C/L)airplane,with an almost new O.S. .35 FP C/L engine,propeller APC 10.5" X 4.5" and 5% (nitro)fuel,and I have a problem with this motor,it always runs steady,two strokes and never 4strokes like old Fox.I wonder how can I do,in order my O.S. runs 4 strokes flying horizontal,and 2 strokes flying vertical.
Thank you for your help.


Carlos
Sign up now
to remove ads between posts
Aug 23, 2010, 07:06 PM
Old Timer
The Kiwi's Avatar
Only the old cross-flow, loop-scavenged engines can automatically shift into a classic 4-2-4 breaking stunt run. There is no good reason to screw up a perfectly good OS Max FP (which is Schneurle Ported) by cutting, grinding, and trying to turn it into something it is not.

Use either a 10-4, or an 11-4, depending on how heavy the plane is, and set for a "rich" two-stroke run. Be VERY sure to use a fuel with LOTS of oil, at least half of which is Castor. I use 25%, half and half Castor and Synthetic oils, with 10% Nitro in my FPs, and they run like a high quality brand of sewing machines, smooth and steady.

On a largish profile stunter, my 40 performed very well with an APC 11-4 prop. One of my 35s, while attached to a terribly overweight foam-wing "Slow Combat" model didn't like that brand 11-4, but was very happy running with a Taipan 10-4.

I have 15s, 20s, 25s, 35s and 40s from the OS Max FP line. I may have a 10 as well, which would be at least one of every size that they made, other than the 60.

Kiwi
Last edited by The Kiwi; Aug 24, 2010 at 09:00 AM.
Aug 24, 2010, 08:36 AM
Registered User
Thread OP

My Tutor and O.S. 35 FP S


.....................I really appreciate all your help.Ill try to do your good advice.Right now Im using some APC 10.5" X 4.5" propeller,I wonder if there is other better propeller I can use,for example some wood propeller or other nylon lighter propeller.


Thanks

Carlos
Aug 24, 2010, 01:06 PM
Old Timer
The Kiwi's Avatar

Try reading what I have already written


There is a 20 or 25% difference in pitch (depending which direction is the desired direction) between the 11-4 I have used and found worked well, versus the failed choice you have made.

K.
Aug 24, 2010, 02:05 PM
Registered User
Thread OP

O.s. 35 fp s


Once again, than you for your help.
Ill change the APC propeller,and Ill put 11" X 4".But there is another problem with the accurracy in setting the needdle valve,its very sensitive,and its quite difficult to set the engine running steady.I wonder if spray bar is installed in my engine in a proper way.Id like to know if spray bar has to be installed with hole facing to specific side.


Thanks


Carlos
Aug 24, 2010, 03:16 PM
Registered User
Gluehand's Avatar
This is how you normally position the hole in the spraybar, twin + single hole types.....

Aug 24, 2010, 05:38 PM
Registered User
I tend to agree with Kiwi. I know those engines like plenty of oil and more than anything I'd make sure I have good fuel with that 25% lube in it. I always set my needle valves with the hole staight down but i doubt that is your problem. You other option would be to do like I did and convert all your controline planes over to electric. That will end the bad engine runs permanantly.
Last edited by bogusbob1; Aug 24, 2010 at 05:39 PM. Reason: misspell
Aug 24, 2010, 06:57 PM
Registered User
Hi Carlos,

If you're really after a nice 4/2 run, have you considered replacing the FP with a Max-S 35? They're not hard to get hold of, and will reliably produce the sort of run you want. The mount pattern is slightly narrower, but this wouldn't be much of a problem.

Steve
Aug 24, 2010, 07:01 PM
Registered User
Gluehand is correct as to how to set the hole in the spraybar. But, in fact, if you can't see it, it will be fine. The prop you are using should be OK. Castor oil in the fuel is necessary; 20- 25% total oil should be fine. I prefer a steady 2 cycle run to a 4-2-4.
Mar 24, 2016, 11:46 AM
Registered User
Carlos,
If you are not getting the engine run with a 4-2-4 break that you are looking for, you need to call Tom Dixon. He reworks engines to give you the 4-2-4 break. His website is Tom Dixon model airplanes His phone is 770-592-3279, he will answer your questions about plug,fuel and props
Happy flying
LeRoy Polk
Mar 24, 2016, 12:00 PM
Old Timer
The Kiwi's Avatar
Several engine tuners have been known to put their talents to use making over these fine engines into something that they were never meant to be. Not saying Mr. Dixon's modifications are either bad or good, just totally unnecessary. There were several east European producers of engines that offered a natural classic 4-2-4 run, and I think that Tom used to import at least one of those to sell.

I've not heard much about those since the CL people interested in stunt competition mostly abandoned classic power systems.


Kiwi
Mar 24, 2016, 12:37 PM
Registered User
That engine isn't going to give you a 4-2 break, as others have pointed out.
I run a 40 0n that prop and I'm thinking you might like a 10-5 or 4 for it.

Inconsistent engine runs are almost always one of 3 things.

First...is the tank in a good location with no leaks and is it tight?

Second....change glow plugs. When it won't stay the same...it's the plug.

Third.....Tom Dixon throws the OS needle assembly in the trash. The braze that holds the needle into it's body fails and you have a needle floatind around giving you contsant changes.
Mar 24, 2016, 12:45 PM
Registered User
Norm Furutani's Avatar
Could also be the venturi is too large. A quick fix/check is to block one side of the needle body with a piece of wood, or less restrictive, a piece of panty hose over the venturi opening. Secure with a rubber band or small tiewrap. If this works, either get a smaller venturi or make a restrictor out of aluminum tubing.

Norm
Mar 27, 2016, 01:12 PM
Registered User
I always used a Fox 35 , OS Max 30 and 35 . I used the OS Max , Fox and Enya spray bars and needles and never had any issues . They all ran really great with the 4-2-4 stroke using 5-10% nitro and 25% castor .
The newer engines run totally different with less oil and using synthetic oil . Maybe I was lucky but I never had a problems and all my planes flew great ! I used a 10x6 on my 35's and a 9x6 on my 30 . I did build a twin engine profile using 2 Enya 19's with 9x6 props . Flew great too . Now back then I used SIG fuel for control line engines and just ran great ! Was 5% or 7% nitro with 25% caster oil . Wish they still made that fuel !!!!!
Mar 27, 2016, 03:57 PM
Registered User
radman615's Avatar
As the old country song says,"Just give it away!"


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
For Sale O.S. .35 FP OS 35 FP for sale alexedit Aircraft - Fuel - Engines and Accessories (FS/W) 4 Mar 02, 2011 10:39 AM
Discussion Restoring a vintage 35 C/L stunter for my Dad's 70th birthday Scirocco14 Control Line 40 Jun 15, 2010 02:41 PM
Sold O.S. 25 FP engine with muffler ncpiperpilot Aircraft - Fuel - Engines and Accessories (FS/W) 2 Feb 01, 2010 11:36 PM
Sold O.S. .15 FP engine with muffler ncpiperpilot Aircraft - Fuel - Engines and Accessories (FS/W) 0 Jan 31, 2010 04:59 PM
Sold SOLD SOLD SOLDNIB Enya .35 Engine R/C or C/L Gonnacrash Aircraft - Fuel - Engines and Accessories (FS/W) 0 Feb 28, 2008 12:50 PM