661 Oil Test 32:1 vs 40:1 vs 50:1 ?

[Trx250r180]

yeah I also had a larger port with the wide weave arrestor screen. It was slower then the .875" with wide weave. When I put in a stock screen into the "larger port" it gained a lot of ground on the .875" wide weave. Seems you Can let out to much. So I'd say there is a happy medium.

A few guys have tested with no cover at all and claim saws do not need back pressure ,look at brads vis ,why did he gain a second ?
Edit
Timberwolf used to do threads like this ,here are some muffler and oil ones ,lot of good reading

http://www.arboristsite.com/communi...er+test&o=relevance&c[node]=9&c[user][0]=2784

 

[redbull660]

..............Maxima........Mobil1.......Motorex........Motul

Iron...............0...............1...............0............0
Tin................0...............0...............0............57
Silicon............0...............0...............0............2
Sodium...........0...............1...............1............3
Titanium.........1...............6...............6............0
Potassium........0...............0...............0............1
Boron.............1...............3...............0............2
Magnesium.......1..............1...............2............2
Calcium.........462.............481............486.........651
Barium............2...............2..............2............1
Phosphorus.......3..............19..............6............62
Zinc...............2..............24..............5............65

Water (IR)...... < 0.1.........< 0.1%.........0.1..........0.1
VIS @ 100C ..... 9.6 cSt......14.3...........12.6.........18.0
TAN..............0.15..........0.49...........0.60.........0.53


Redbull -

I keep seeing the above chart talking about the tin zinc phosphorus and calcium content in motul ...i assume 800. Is this because it sucks or because of the formulation? ie. 100% ester? is it bad? What does h1r look like? Maybe H1R , R50, Stihl ultra maybe all similar metallic #s to motul's numbers...because they have somewhat similar make ups?

--------------------------------------------------
Belray - (Andrew)

As far as I know, the 800 is good, they have the metallic additives because I assume they found that they work well. Metallic content does contribute to ash content, but if the detergency is good, then it’s not necessarily a problem. Remember, no one thing makes an oil bad or good, you need to look at the big picture. There are standard requirements to how much ash content you can have for the API and JASO regulations, but I do not know how the 800 stacks up against them.


The only metallic in H1-R is calcium and it is at about 203 ppm so it’s about 1/3 of the 800 and half of the others according to that chart that keeps getting posted. Also as a side note, 65 ppm of zinc is miniscule, that could just be residue left in the blending tank from whatever they manufactured before the 800. As a reference point, common 4 stroke motorcycle oils have a zinc content of around 900-1200 ppm. I don’t know about zinc content in 2-strokes oils though. I just know that I keep our metallic content to a minimum to minimize ash and pollutants.

 

[the GOAT]

RESIDUALS left in the tank!!!! OMG.

 

[blsnelling]

A few guys have tested with no cover at all and claim saws do not need back pressure ,look at brads vis ,why did he gain a second ?

Because they don't need back pressure. We're not running tuned pipes here.

 

[redbull660]

A few guys have tested with no cover at all and claim saws do not need back pressure ,look at brads vis ,why did he gain a second ?

I'll put my 875" mod, up against "no cover" any time u want. But not with my saw.

the way it was explained to me by my motocross buddy was yes back pressure isn't as much of an issue at top end. but at idle and or low rpm, it's a problem. I don't remember why though.


but the bottom line is - results. and im seeing the best results with the .875" wide weave. Could that change with a ported saw...hell yeah!

 

[blsnelling]

I'll put my 875" mod, up against "no cover" any time u want. But not with my saw.

the way it was explained to me by my motocross buddy was yes back pressure isn't as much of an issue at top end. but at idle and or low rpm, it's a problem. I don't remember why though.

Totally different application. Like I said, these aren't tuned pipes.

 

[redbull660]

Totally different application. Like I said, these aren't tuned pipes.

like I said < I'll put my .875 mod up against anything. no baffle, no cover, 3" hole in the cover, no muffler on at all ...whatever. Based on my testing...I bet I'll win.

disclaimer - except piped. i just know someone gonna come up with that. lol

 

[bwalker]

Never had a problem with not running screens.

 

[blsnelling]

Timberwolf did documented testing years ago. His findings where exactly what I demonstrated. His findings were that the larger the open, the faster the cut times. However, it was a case of diminishing returns after a certain point, and idle and throttle response might suffer.

Not only were my cut times measurably faster, but throttle response was amazing. The MTronic completely compensated for it.

 

[bwalker]

like I said < I'll put my .875 mod up against anything. no baffle, no cover, 3" hole in the cover, no muffler on at all ...whatever. Based on my testing...I bet I'll win.

disclaimer - except piped. i just know someone gonna come up with that. lol

I believe you to be right. Years ago I did some testing on a stock ms 440 and ported ms260 and found that once you went over a certain area of muffler opening torque fell off and so did cut times. I have also muffler modded saws and noticed no differance other than increased noise.
Likely what size opening a saw likes is highly model specific. With that said I no longer will own a saw with too much muffler opening, ported or otherwise. I have 90% hearing loose in some frequencies in my left ear, and would like to preserve what hearing I have left. Even with plugs and muffs, my ported EHP 346 makes my ears ring for hours.

 

[Big_Wood]

my dad gave me this book when i was 6 LOL mufflers these days are what they are because of the EPA and to keep noise levels down. if performance was top priority there would be no back pressure at all. despite the long live AS myth that there must be.

 

[nitehawk55]

RE: TCW3 marine oils. Back in the 90's snowmobiles OEM's reccomended their sleds be an on tcw3 oils. They worked ok, but we're a little dirty depending on the oil. Output began to really climb and exhaust port height modifying valves became common place so the OEM'S changed to low ash, API TC type oils.
In 1996 IIRC I had a polaris 440 race sled that was the first polaris motor with exhaust valves. Using Phillips injex, which was a decent quality outboard oil, the exhaust valves seized within 500 miles. When I removed them I noted the pistons looked terrible too. Ever since this I have not run a tcw3 oil in anything other than an outboard and even then am quit picky on what oil I use. The only exception is Lawnboy mowers which really require a ashless tcw3 type oil.

On the Lawn Boy , I've run both my F and D series mowers for years with Stihl Dino oil at 50:1 and never had to clean the exhaust ports which is common with dirty oils . Ports have stayed very clean as well as the piston . Of course these engines are only running at around 3500 RPM .

 

[nitehawk55]

Depending on how the temps are being taken there will be a good bit of variety with any change made.

I think the belief is that a modified saw will run "cooler" but could benefit from more oil because of the increase in various stresses, mostly bearings. If somebody " modified" one of my saws(made it louder) and made it run measurablely hotter at the same time I would not be pleased.

Get a temp for the saw at idle and then from as screaming hot as you are willing to get it, then compare how long it takes to cool back down to idle temp, with the spark screen change. Screaming hot, not warmed nicely, make sure to leave just enough fuel in the tank to allow for the saw to cool back down to idle.

It's usually tampering with the ignition timing that can make them run hot .

 

[blsnelling]

I have NEVER seen a muffler mod slow a saw down. I've seen them not make much difference, but even that is very rare. Why do you think stock appearing race saws often shoot straight out the front of the muffler? Giving the exhaust the path of least resistance will make the most performance.

Now with that said, I don't think overly aggressive muffler mods are necessary for a great running saw, even ported. Many don't want the extra noise. But, in principle, the more the merrier.

 

[bwalker]

On the Lawn Boy , I've run both my F and D series mowers for years with Stihl Dino oil at 50:1 and never had to clean the exhaust ports which is common with dirty oils . Ports have stayed very clean as well as the piston . Of course these engines are only running at around 3500 RPM .

I tried running my lb duraforce commercial on 50:1 Husky oil and toasted a big end rod bearing. The rod bearing on the duraforce is so chincy I wouldn't trust anything less than 32:1, which is what lb recomends. I also went through a plug or two a year using low ash oil. Its a shame the damn things have fixed jet carbs as I
I am sure once tuned right the plug fouling would stop.

 

[Trx250r180]

yeah I also had a larger port with the wide weave arrestor screen. It was slower then the .875" with wide weave. When I put in a stock screen into the "larger port" it gained a lot of ground on the .875" wide weave. Seems you Can let out too much. So I'd say there is a happy medium.

On a 661 stock saw that medium seems to be having the wide weave screen with a port at ~.875"-.900" If u wanna run the stock arrestor screen then you'd need to make the port just a bit bigger yet.

I will have to measure my hybrid ,but i am willing to bet my 3 exhaust ports are close to or bigger than the exhaust port in the head ,and it runs well .,i have found the screens will muffle noise some also .

 

[Trx250r180]

I tried running my lb duraforce commercial on 50:1 Husky oil and toasted a big end rod bearing. The rod bearing on the duraforce is so chincy I wouldn't trust anything less than 32:1, which is what lb recomends. I also went through a plug or two a year using low ash oil. Its a shame the damn things have fixed jet carbs as I
I am sure once tuned right the plug fouling would stop.

It would sure be nice if saws carbs were as tunable as a 38mmm air stryker keihin ,could always run a lean pilot and fat needle to get nice throttle response ,but i can not find any clips on my needle in the saw to adjust ,and the pilot is fixed i believe

 

[windthrown]

Never had a problem with not running screens.

That will get you a fat fine here if they catch you w/o a muffler screen. If you start a fire with a saw (or anything else) they can bill you for the fire suppression fees, which can be in the million$ here.

 

[SAWMIKAZE]

I just run less restrictive screen..i just dont want any tarantulas crawlin in muh saw.

 

[Ron660]

This is the oil a local Logger prefers. He said he gets about 5 years out of his 372's mixed at 25:1. I bought this bottle, 6.4oz, for $1!