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Engine basics => Four strokes only => Topic started by: Randy Ryan on July 10, 2012, 08:02:25 PM

Title: Plugs!!??
Post by: Randy Ryan on July 10, 2012, 08:02:25 PM
OK 4 Strokers, after a layoff I'm back at my 4S experimentation. I'm running a Saito .56 on a Score. I flew this combination a few years ago and really liked it so decided to try it myself. So here's the question. I'm running 10% Coolpower, what glow plug should I be running. Currently has an OD F but the engines balks when ai take the booster off and its pretty cruddy. Is this a good plug for this purpose or is there something better?
Title: Re: Plugs!!??
Post by: Bob Reeves on July 11, 2012, 09:02:55 AM
OS-F is what I run and have so far not had to replace a single one, they seem to last forever.. In fact the Saito 56 I was flying at Brodaks this year was the one I flew the heck out of in a Score 4 years ago and it still has the same plug.

To get your Saito running well, may I suggest you take at look at the info I put together on the Gluedobbers web site.

http://www.tulsacl.com/SaitoCarb.html

Even if you don't do the carb mod, the info toward the bottom under "Setup and Flight Performance" is what I discovered after much experimentation over several years.
Title: Re: Plugs!!??
Post by: Randy Ryan on July 11, 2012, 09:06:18 AM
OS-F is what I run and have so far not had to replace a single one, they seem to last forever.. In fact the Saito 56 I was flying at Brodaks this year was the one I flew the heck out of in a Score 4 years ago and it still has the same plug.

To get your Saito running well, may I suggest you take at look at the info I put together on the Gluedobbers web site.

http://www.tulsacl.com/SaitoCarb.html

Even if you don't do the carb mod, the info toward the bottom under "Setup and Flight Performance" is what I discovered after much experimentation over several years.

Thanks Bob, fixed venturi, I'll have a look see.
Title: Re: Plugs!!??
Post by: proparc on July 11, 2012, 02:30:51 PM
If you using an OS Max F plug and the engine balks when you remove the booster, you have a fuel\delivery problem.
Title: Re: Plugs!!??
Post by: Randy Ryan on July 12, 2012, 03:48:31 PM
If you using an OS Max F plug and the engine balks when you remove the booster, you have a fuel\delivery problem.

It's been a while and I forgot that I WAS running muffler pressure but did not the other day when I experienced the bogging. I will try it with pressure and I'm looking at some variant of Bob Reeves choked venturi on my fixed venturi Saito. Also need ot revisit props.

Title: Re: Plugs!!??
Post by: Randy Ryan on July 12, 2012, 03:50:10 PM
OS-F is what I run and have so far not had to replace a single one, they seem to last forever.. In fact the Saito 56 I was flying at Brodaks this year was the one I flew the heck out of in a Score 4 years ago and it still has the same plug.

To get your Saito running well, may I suggest you take at look at the info I put together on the Gluedobbers web site.

http://www.tulsacl.com/SaitoCarb.html

Even if you don't do the carb mod, the info toward the bottom under "Setup and Flight Performance" is what I discovered after much experimentation over several years.

Bob, what was your lap time with the Score and FA-56? I like to fly slow, 5 seconds or a little more. Is that realistic or do I have to get used to a little higher speed!
Title: Re: Plugs!!??
Post by: Bob Reeves on July 12, 2012, 05:22:32 PM
I flew the Score a little faster than I'm presently flying the Latency, Score ran 4.9 to 5, Latency 5.1 to 5.2. both using 63 foot lines. I've flown complete patterns with the Latency at 5.6 but it was pretty light on the lines up top, reminded of the days we flew 60 size ships with a 46. The Latency is lighter than the Score and in better trim.

The slower you fly the more important it is to have the airplane in proper trim. Speed can cover up some pretty bad trim or airframe issues.
Title: Re: Plugs!!??
Post by: Dan McEntee on July 30, 2012, 06:00:42 PM
   I still have the stock Saito plug in my .56 that was in it when I bought it, and I don't know why a Glow Devil 4 stroke plug or even a Glow Devil R/C long wouldn't work.  Mine runs fine after three years and I haven't had to set valve yet either. If the engine runs fine, I figure why bother?  For what it's worth, I have mine in a Score that weighes 70 ounces, and I'm running Bob Reeves' screw set up, and a regular plumbed plastic 4 ounce Sulivan tank on muffler pressure. For prop, I have been using 13-7 Rev-Up or 13-7 Vess at take off RPM betwen 7800 to 8000 RPM. I'm full out on lines at 70" handle to centerline of the model and lap times between 5.3 to 5.5 seconds. Been loving this combination since I got it all figured out, and just need the spare time to build another model for a Saito .62 I have.
    Type at you later,
      Dan McEntee
                   
Title: Re: Plugs!!??
Post by: proparc on July 30, 2012, 07:19:32 PM
OK 4 Strokers, after a layoff I'm back at my 4S experimentation. I'm running a Saito .56 on a Score. I flew this combination a few years ago and really liked it so decided to try it myself. So here's the question. I'm running 10% Coolpower, what glow plug should I be running. Currently has an OD F but the engines balks when ai take the booster off and its pretty cruddy. Is this a good plug for this purpose or is there something better?

Something wrong with the fuel blend. I'd switch fuel before I would switch out F plugs. More nitro? Remember an F Plug can go bad after a while. Maybe filament shot.
Title: Re: Plugs!!??
Post by: Bob Reeves on July 31, 2012, 09:08:17 AM
Working with Gerald from the "Ragged Runs" thread sure told us how important using Power Master YS-20-20 is to getting these things running properly. Because I switched to YS 20-20 very early in my 4 stroke development I was not aware of just how important the 20-20 piece of the puzzle is. I have always reccommended it but not having tried other fuels wasn't sure if my set up would actually work with anything other than YS 20-20.

I am now convinced that if you are going to run a 4 stroke do whatever it takes to get your hands on a few cans of Powermaster YS 20-20.