Not sure if you have the 3 bolt backplate or 4 bolt backplate versions, so.....

Fox 19 (3 bolt) 5.2 oz
Fox 25 (3 bolt) 5.0 oz

Fox 19 (4 bolt) 6.0 oz
Fox 25 (4 bolt) 5.9 oz

The 25's are actually lighter than the 19's in both cases.

Just for fun..... Fox .201 (3 bolt) 5.2 oz.

Thanks guys.  I am going to use the OS FP 15.  I ordered a needle valve today.  (already had the venturi)

I appreciate the engine info. 

In this instance I have to agree with Bill on a choice of power. That airframe was designed around the old Fox 15 rocket and 15x models. Even with a 15X it moves at a fast clip . An OS 15FP is really a lot more engine then the old Foxes and will if you are not an experienced flyer give you the ride of your life.
I keep reading of guys using McCoy 19's and other large engines and can't fathom any of them ever being fun to fly. they will be too fast and much too nose heavy to do much of anything. Find an OS LA10 and use that. you will be pleasently suprised as the flying habits of that little model.
dennis

OS10fp-s
Venturi part#21112003
NVA part#21111006

How come none of our machinist friends won't make us needle valve assemblies?

Hi Rusty,

For the majority of engines we now use, finding a NVA that fits isn't usually a problem.  The OS .10 FSR or FP is just one that is a completely different style from all the other OS engines.

Big Bear

Was the .10fsr-s the only c/l motor of the fsr series? (snip)

Could read that quip a lot of different ways............

Big Bear

Hi John,

The FSR series were EXTREMELY popular not too long ago (pre piped set ups), and saw extensive use by many.  I *believe* Bobby Hunt used a .40 FSR in his World Champion Genesis, which had previously been powered by an ST .46.  And in his Genesis .40.  Paul Walker won a NATS, IIRC with an FSR (.40 or .45??), and lots of other top fliers were suing them when they were fairly new.  One of the early schneurle ported engines used in large quantities.  I am not sure if the .40 and .45 were released as "S" (C/L) versions, though, but it wouldn't have been unlikely for OS to have done so, since they have usually done that in the past.  The series just before ("H") were sold as C/L versions.

The problem we have been discussing about the .10 FP/FSR needle valve assembly is that they used a specific size and no "spring shank" needle.   So far I haven't been able to cross reference any "other" series NVA as a direct drop in.  If anyone has, I would love to find out.

The FSRs are strong, and were not the usual "4-2" break engines out of the box from what I remember on the .40s and .45s.  I seem to remember that they were in the early stages of the high rpm/low pitch prop, but I might be off on that.  They are very viable today for stunt use, but most of (all?) the  top rank fliers want to use engines that are still "on the market" so to speak for replacement parts, etc..  Probably not what one would use in a piped set up, of course, but more than enough to power appropriately sized models.  For local use and sport stunt, they still are good engines.

Many, if not most, of the R/C engines from the past 20-25 years will work, if run properly, today for us.

Thanks!
Bill

Thanks Bill,I have a .10fp that i would like to convert. I have the exploded view manual that clearly shows the nva that you are talking about(.10fsr shown is r/c)it seems that might be a hard to find part as well as the 15fp-s the rest of the fp series i have seen all over feebay.      John.

PS if you ever need pics of the manual i can post on rcg(still working on the pic reduction thing)it has been very useful over the years for part# and working on fourstrokes.

Hi John,

I get the NVA and venturi for the .15FP from Tower.  Just got a set about three weeks ago.  I had to search OS .15FP on their data base, and look through everything they list for it.  Probably find it quicker by using the part number at Tower, though!

Bill

The FSR series were EXTREMELY popular not too long ago (pre piped set ups), and saw extensive use by many. 

   Oh, Bill, "not too long ago" = 30 years!  I have the same thing - I have to catch myself when talking about what happened in the 70's and 80s with a lot of my colleagues. Seems like yesterday to me, most of them weren't *born* then.

  FSRs were mostly dead meat when someone discovered the ST60.


   Brett