airraptor

My Feedback: (66)

to say you have used it for eight years doesnt tell us anything lol you could only only run the engine once a year for 30 years and say the plug has lasted 30 years. gsllons thru the engine is good.

again on new engines i use a old plug since everything is breaking in.

drac1

My Feedback: (4)

The symptoms you are describing doesn't sound like a crook plug. It sounds like moisture in the fuel. A crook plug will drop rpm when the glow driver is removed.
Plugs are inexpensive these days so it isn't worth the hassle of cleaning them.
Fuel stored correctly in an airtight container will last for years. I've had fuel stored for 5 years and it still ran perfectly when used.
I also use a new plug in a new engine and i leave that plug in untill the idle starts to change. I've got engines that have had the same plug for years and i run 30% nitro.

fourstar40

My Feedback: (27)

Good point. ANd you're right. I probably only fly my Cub a couple of times a year. Strike my last comment. lol

MTK

Ding, ding , ding.....Raptor hit the ringer. In addition to the platinum elementfouling with use, bearings play a major role too.

To the OP, four strokes love the OS F plugs and need to have good bearings for proper operation. Four strokes also love high nitro fuel with fairly high oil content, higher than 2 strokes need. One of the best fuels you can run in a 4 stroke is Cool Power 30% Heli blend. You can mix it down to 25% if you want but I wouldn't run anything less than 20% nitro in a 4 stroke. They simply behave better, have better field manners and spool up better with no hesitation after extended running in mid range or idle. Try it I think you will like it

jeffie8696

Uh oh, high nitro suggestion, you are gonna get it.

JPMacG

My Feedback: (2)

MTK is correct, Saitos like high nitro. But I'm cheap and just fly sport, so I am satisfied with 10%. If I flew competitively I would probably buy 30%.

But, on the other hand, my Enya 4-stroke seems to run best on 5%.

MJD

My Feedback: (1)

When I went up to just 20% on my Saito .72 from 10%, I was very pleased with the overall improvement in manners. And I felt I could set it a little rich on the top end and still have lots of chug in the verticals. It's getting a little tired.. time for the 30%?

1QwkSport2.5r

I was gonna say... Loads of nitro in all 4-strokes except Enya 4C's. Mine runs no different on 20% as it does on 5%, and it really likes 20% castor. I quit hand starting it, getting whacked by a big APC hurts.

You Saito and OS 4-stroke guys can enjoy your 20-30% nitro. That stuff is too darn expensive here in MN. I like my 5% fuel, it's cheap.

I'm a McCoy glow plug fan myself, though I recently tried Enya plugs in my 4C. My OS F plug I have is in my "break-in" box. Not happy with it.

jeffie8696

My Saitos are so well mannered they will run on anything, I use 15% in all of them.

NM2K

My Feedback: (14)

Yeah, it's the over rated, el cheapo built, expensive engines that actually need high nitro fuel to run worth a hoot. (grin)


Ed Cregger

bogbeagle

My plugs seem to last forever.

I honestly cannot remember the last time that I changed a plug; certainly not this year. Flown 32 hours, this year, to date... using just 3 glow engines, all on straight fuel. (OS F and Enya 3 plugs)

I don't know whether the battery-powered glow-driver helps to extend the life of plugs. I mean, you cannot over-drive the plug and cook the element, in the way that you can with those power panels.

1QwkSport2.5r

I was waiting for this.

NM2K

My Feedback: (14)

Truthfully, I probably own as many Saito engines as any other single brand and the ones that I have ran, ran superbly.


Ed Cregger

MJD

My Feedback: (1)

Funny how this works. I tried a variety of 4c plugs, and experienced the best overall behaviour on the OS F.

1QwkSport2.5r

I got the same top rpm between the F plug and a Fox idlebar plug, but the idlebar gave a much lower and stable idle. A McCoy MC4C and Enya #3 gave very similar performance to the idlebar plug, but transition is better. This is all with an Enya 60-4C which is an engine that likes to burble at idle. A Fox miracle plug wasn't even a contender. Top rpm was down 2000rpm from any of the plugs I tested, and idle quality/transition was poor. This is of course using 5% nitro and 20% castor fuel. I now use an Enya #3 in the 4C.

I will add, I've noted numerous differences in how engines run for me in MN than for others in various parts of the country/world. I easily get 1000rpm less than someone right at seal level. I'm at approx 900ft ASL.

rcfan450

Ok fellas, it's time to return and report. I bought me a brand new bottle of 30% Heli Cool Power. That's what I've always ran, tried 20% and didn't like the performance out of my 2-stroke or 4-strokes with it, I like POWER! (and I need it at 6000')

The verdict. It ran perfectly, or so I thought.

But... I also bought a new OS F plug. It already had an OS F plug in it but that's the one that was in question.

So before changing the old plug I started it with the igniter on and left it on for a bit to make sure the motor was warm. Checked rpms with rpm gauge for while, then took igniter off. There was about 100-150 rpms drop with igniter off. So the rpms went down, but not by much.

I then put the new plug in and did the same thing. Rpms went down by maybe 50 rpms, it was hard to tell it even changed. With the old plug there was a noticable sound difference in the motor when I took it off, with the new plug there was hardly any sound difference at all.

So I think the plug maybe isn't 100% anymore, but most likely the underlying issue was bad fuel. It was the bottom of the barrel (so to speak) for that gallon of fuel and it was at least a year old, if not more.

THEN.... I tried the old OS F plug in my Saito 100 (different motor) that is still running on the original saito plug that comes with the motor. I bought this motor used. It has no compression and doesn't idle too well but still hovers my U-Can-Do around so I don't mess with it. I have no idea how old the motor is. The old OS F actually made a big difference! It went from "have-to-run" around 2000 rpm or it would die to 1400 rpm and it won't die, even when I let it sit there for several minutes just to see if it would die. It never did. Even a hard push on the throttle didn't kill it either. So that makes me happy. The original saito plug had coils that were kinda bent and you could tell it had had it.

So ya, plugs wear out... and so does gas! ha ha I'm gonna buy a new OS F for the Saito 100 as well.

I think I will buy some cheapy gaskets for the carb next time I order anything from Horizon just to make sure those are good too.

And speaking of 2-strokes, I have an OS A3 plug and it seems to be ok in my OS 91, but would the Enya-4 (I think that's the one mentioned earlier) do any better?

Thanks a bunch for all your replies folks!

rcfan450

Oh, and one more thing I just thought of. I had put some fuel fragrance in my other gallon of fuel. This new bottle didn't have anything in it. Have you guys heard if that can cause any issues or not? They claim it doesn't but I gotta wonder.

jeffie8696

Iwould amagine that anything that is not a fuel like methanol or nitro will inhibit the ignition but to what extent Idont know. Iknow that too much anti foam agent will cause an erratic idle.

1QwkSport2.5r

I use regular run-of-the-mill food coloring dyes to dye my homebrew fuel. I have no issues, even using 2-3 drops per quart. I've used armorall for defoaming agents and haven't had much issue other than if the fuel with armorall isnt used up quickly enough, it will need to be added again as the armorall will break-down and settle out of solution after a week or so. I tried a fuel fragrance once, I think it was supposed to be vanilla. I kinda got a whiff of vanilla here and there, and the car ran fine... But the fragrance's solvent was alcohol. Shouldn't really be an issue unless its a water-based fragrance.

Even then, a glow engine will run pretty normal with 10% water added to the fuel. There were videos and a write-up about it some time ago.

jeffie8696

Must have been a Traxxas

mike109

G'day

Had an interesting time with plugs today. A friend's ASP ( like Magnum) 91 four stroke needed a plug. We did not have any "four stroke" plugs available but I did have a couple of Enya #3 plugs and I had heard that they were used in Enya four strokes so we plonked one in.

Fuel was my usual mixture. 10% nitro, 5% castor, 15% Klotz and 70% methanol.

The engine is mounted inverted and is not very old but has about an hour's running. Initially the motor ran OK but was way too rich top and bottom. I then tuned it by the Hobbsy method (tune top end to peak revs then set the bottom and repeat as necessary). She ran much better and the Enya #3 seemed to be fine.

I tried the "remove the plug at idle and listen for a rev drop" and there was a small drop but the engine has a nice stable low idle and a good transition. And it does all this inverted inside a cowl.

Seems that Enya #3 plugs work well in four strokes. They have also sorted out my cranky (initially) Super Tigre 51 and turned it into a fine runner.

Mike in Oz

1QwkSport2.5r

Nah, it was a Losi.. .

jeffie8696

Losi? elitist.

1QwkSport2.5r

LOL! Hardly. I have two LST2's. they are "stupidly overbuilt". Their engines are idiot proof to tune, and like nitro. Almost impossible to keep it on all fours on 25%, so I drop to 15-20% and use hot plugs. I get 2-3 gallons to a plug in these engines.

Maybe I'll try a couple squirts of CoolWater cologne in the next tank of fuel. See if it will attract hoardes of women to my door. Hah.

jeffie8696

No no no, AXE is the stuff.