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-   -   OS 1.40RX FI conversion (https://www.rcuniverse.com/forum/rc-pattern-flying-101/10112872-os-1-40rx-fi-conversion.html)

randy10926 11-03-2010 08:42 AM

OS 1.40RX FI conversion
 
A club member is selling a used os1.40 rx fi fir a nice price. A normal RX carb has been placed on it and all the FI stuff taken off. Any one know of a problem from doing this? Thinking that it will go well with a HINDSIGHT. A little concerned about timing issues, etc.

DaveL322 11-03-2010 08:59 AM

RE: OS 1.40RX FI conversion
 
If you replace the carb with the RX carb, and replace the backplate with the RX backplate pump, it will for all practical purposes be an RX.

The only thing the EFI really did was control fuel flow based on RPM and throttle position. Yes, it also had a temp sensor, but I flew them many flights without the temp sensor connected.

Timing is not an issue. Timing on a 2C is controlled by a combination of compression, heat range of the glow plug, and mixture, and this will be the exact same as a stock RX.

If you want a great deal on a 2nd low time EFI (with Shadel piston/liner, SS BB, new rod), PM me.

Regards,

Ryan Smith 11-03-2010 10:13 AM

RE: OS 1.40RX FI conversion
 
Randy,

I've done this a couple of times and have had no issues with it. Back when I was running OSs, I sold a 1.40 RX EFI to Blaire Page and converted it over for him and he flew it a bunch with no issues, and when I had some bearings go bad in a 1.40 RX and didn't have any spare bearings, so I converted a new EFI over to an RX and flew it for a while with no issues. Two strokes are pretty simple.

randy10926 11-04-2010 08:51 AM

RE: OS 1.40RX FI conversion
 
Well I need simple engines. I do not seem to be able to keep anything more complex running.

Man even my first electric caught fire in flight.

Gregg G 11-04-2010 10:20 AM

RE: OS 1.40RX FI conversion
 
Hey Randy, I know this may not apply in your situation, but I've got a YS 170 cdi that is just rock solid and is by far the best running YS that I have ever had.

rcpattern 11-04-2010 11:03 AM

RE: OS 1.40RX FI conversion
 
Randy,

I do agree with Greg. The 1.70DZ's are every bit as easy to run as the 1.40RX's were. The CDI's are even better.

Arch

flywilly 11-04-2010 02:59 PM

RE: OS 1.40RX FI conversion
 
Read the thread (in this forum) about the YS 170DZ CDI. It is very hard to beat the simplicity and ease of operation of the 2-stroke engine which does not require 30% nitro. If you are flying in the lower classes there is not the need for the extra power of the YS 170, in my opinion, and the most important aspect of pattern is the ability to practice effectively without equipment issues. The improvements in electric propulsion systems are making glo engines obsolete in pattern (sadly).

rcpattern 11-05-2010 12:55 PM

RE: OS 1.40RX FI conversion
 
Flywill,

The YS 1.70DZ will run fine on 15% Nitro. Having owned and flown OS 1.40RX's for years and YS 1.70DZ's for years, they both are VERY easy to operate, but honestly I had less problems with the 1.70's. Even changing the bearings in the OS 1.40RX you will still have problems with them sooner than you do on the YS. The 1.70's were by FAR the easiest running glow motors I've ever owned. I've now switched over to electric, and I know Randy already has the 1.40RX's and is going to run them, but I want to make sure people understand just how simple the YS's are. They do NOT need 30% nitro to run well. They are very happy on 15%.

Arch

MTK 11-05-2010 02:18 PM

RE: OS 1.40RX FI conversion
 


ORIGINAL: rcpattern

Flywill,

The YS 1.70DZ will run fine on 15% Nitro. Having owned and flown OS 1.40RX's for years and YS 1.70DZ's for years, they both are VERY easy to operate, but honestly I had less problems with the 1.70's. Even changing the bearings in the OS 1.40RX you will still have problems with them sooner than you do on the YS. The 1.70's were by FAR the easiest running glow motors I've ever owned. I've now switched over to electric, and I know Randy already has the 1.40RX's and is going to run them, but I want to make sure people understand just how simple the YS's are. They do NOT need 30% nitro to run well. They are very happy on 15%.

Arch
Ed Alt runs his on 20% and it runs fine. Used 30% only during high Summer heat. It doesn't make any sense to run 30% in the cool of the Fall, especially for a 10 lb airplane.

randy10926 11-08-2010 10:44 AM

RE: OS 1.40RX FI conversion
 
Well I can purchase a lot of used 140RXs for the price of a new 170CDI. Since I am just moving up to Advanced they should work with a lighter plane.

Now as my daughter is finished with college soon and moving to a different power plant becomes possible next year. I am thinking of moving to electrics. I will need to figure them out with something beside my contest planes thoughe. Seeing my practice Focus Sport smoking across the sky was not any fun.

MTK 11-08-2010 11:41 AM

RE: OS 1.40RX FI conversion
 


ORIGINAL: randy10926

Well I can purchase a lot of used 140RXs for the price of a new 170CDI. Since I am just moving up to Advanced they should work with a lighter plane.


Yes, no question about that one. And just because the big dawgs have move to other powerplants besides the OS140RX, does not make this engine any less viable. In the right hands and right airplane weight, it will win at any level of competition.

Good luck with whichever approach you take.

I personally still use 2 stroke powerplants (one of the few remaining diehards I suppose), except mine are gasoline burners.


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