084 concerns & questions

[joed1694]

I am not proud of myself but , this weekend i got a really good deal on a stihl 084. The saw ran but did not oil, so i started disassembling it and found that the saw had only one ring but the piston has two grooves. the saw also has a k&n air filter and someone has installed an additional hole In the muffler .

I am not a stihl man so can anyone help?

thanks Joe



running saws
4 1/2 jonsered 920's
stihl 011

 

[Lakeside53]

either it's eaten a ring (not likely wih big damage) or someone decided it didn't need two - it does.

Sounds like it's been messed with...

 

[joed1694]

What would be the advantage of only running one ring? The saw ran really good before i tore it down. I wish i had checked the comp.

 

[whatsnext]

What would be the advantage of only running one ring? The saw ran really good before i tore it down. I wish i had checked the comp.

For whatever reason some people think using only one ring reduces friction and allows the engine to produce more power.

 

[Lakeside53]

it will have less friction, so if you're racing, maybe it will help for a SHORT while

or, more likely, there were two, but one got broken during insertion, so, to save money.... sad... but I did see a couple of 029's from the WA state auction with NO RINGS. They has been run, breifly! Nice pistons though.

 

[whatsnext]

But the saw has been 'modded' so it probably is for 'professional' racing use. Or the seller just broke one or is a dork.

 

[joed1694]

I just made a call to the bone head that i bought it from and he said he ran it for about a year and sent it to a so called stihl performace shop and they did that. He also said that it ran better after he got it back. If my stihl dealer is open tommorrow i believe i will put second ring back on so i can have piece of mind. what do you guys think. Should i call WA hot saws for advice?

 

[whatsnext]

Who knows what else the "so called stihl performace shop" did to the saw. There is no point buying a ring until you know the bore size but once you do, why not. How much did you pay for it? You might want to post this over at the EHP forum because those guys may have a better idea what will happen if you leave it alone. I usually side with the designer of the saw but that's just me.

 

[joed1694]

I only paid 150.00 for the saw with out a bar. thats why i thought i better buy it. If stihl designed it for two rings then i think it oughtta have both of them. I sure wish someone would take this off of my hands and trade me some good saws (jons 920's).

 

[joed1694]

But the way tell me what the EHP forum is.

 

[whatsnext]

But the way tell me what the EHP forum is.

I think this will get you there but if not go to the AS home page and look under 'sponsored forums'

http://www.arboristsite.com/forumdisplay.php?f=32

You should find out the name of the saw shop that did the work because these guys may know them.

 

[PWB]

Have to see what the pros say, but I know that a two stroke bike I had a lot of years ago came with a 2 ring piston on the "enduro" (streetable) version, and a one ring piston on the "MX" (race) version. Found this out because the dealer only had the "MX" piston in stock when I needed one. Was probably intentional. A good Idea? That's another question.

 

[bikepilot]

Still the same way with bikes - Most of the racing 125cc class bikes use one ring, while the 250cc class bikes usually come with two, but all the high performance aftermarket pistions use only one ring.

I wouldn't be worried about one ring on a piston designed for one ring, but I'd worry about just running one ring on a 2-ring piston. I would think that the piston would be designed to use that extra ring for additional stability in the bore and you might induce piston slap and pre-mature skirt failure without both rings. Just a thought, I don't know for sure, but if it were me I'd run however many rings there are groves for on the piston.

good luck

 

[Mr.]

You have a pm. I can help you with this one.

Fred

 

[Lakeside53]

Who knows what else the "so called stihl performace shop" did to the saw. There is no point buying a ring until you know the bore size but once you do, why not. How much did you pay for it? You might want to post this over at the EHP forum because those guys may have a better idea what will happen if you leave it alone. I usually side with the designer of the saw but that's just me.

It's unlikely the bore size changed as it's nikersil coated. Put in two NEW rings... not just one..

If you're going to use it as an "ordinary saw", I'd go over it from end to end... and figure out what was done.

I've often wondered what happened to "hot" saws when the owner got tired of them

 

[Mr.]

After a thread a while ago. Some of us have overbored alot of saws. Check the bore.

Fred

Some good results some o.k.. You gotta pay to play.

 

[Lakeside53]

After a thread a while ago. Some of us have overbored alot of saws. Check the bore.

Fred

Some good results some o.k.. You gotta pay to play.

Check it for sure, but if you "overbore" a Stihl, you'll need to replace the nikersil ($$) or it will last about 10 seconds...

 

[Mr.]

Check it for sure, but if you "overbore" a Stihl, you'll need to replace the nikersil ($$) or it will last about 10 seconds...

True and it places a burden on one to get in tight with a saw builder that can make custom pistons if it's a 084 or 3120/

Fred

Newbies, search for chrome, nikosil, or overbore and you will find the people you need to make it happen. Lakeside already has the skinny.