Read Gum dust and Stihl HD Filters

[billyj]

i ran some gulf western through my 2 little beaters before i got the 7901 and it caused them to both strip the plastic gears in the oilers.

currently running penrite b&c oil with no complaints but im only an occasional user, wouldnt have put more than 6 tanks through the 7901 since i got it last oct

 

[porky616]

sort of but a little bit piney, some of the best stuff I have used was what we used to sell through shell when I was a teenager it was torcula rockdrill oil if my memory serves me correct was tacky as all and all the pine fallers around mt gambier used to buy it off us.

hmmm i know of a couple drums of that, and a mates a driller on the mine might have to try me luck

 

[masculator]

i ran some gulf western through my 2 little beaters before i got the 7901 and it caused them to both strip the plastic gears in the oilers.

currently running penrite b&c oil with no complaints but im only an occasional user, wouldnt have put more than 6 tanks through the 7901 since i got it last oct

Hope the penrite bar oil is better than their 2 stroke oil. at work one of the mobs that WERE using it in their 2 strokes spent a shipload more in maintenance on their whipper snippers and chainsaws than they saved by using it. It wouldn't dissolve properly in the fuel and you would pull the carbies apart and they would be full of oil. personally I think it is what caused my 034 to fail and I was using their synthetic.

 

[masculator]

hmmm i know of a couple drums of that, and a mates a driller on the mine might have to try me luck

would be better than gulf western and probably cheaper.

 

[porky616]

would be better than gulf western and probably cheaper.

everythings cheap under the cover of darkness:hmm3grin2orange:

 

[masculator]

everythings cheap under the cover of darkness:hmm3grin2orange:

Unless you tell everyone and get busted!

 

[billyj]

Hope the penrite bar oil is better than their 2 stroke oil. at work one of the mobs that WERE using it in their 2 strokes spent a shipload more in maintenance on their whipper snippers and chainsaws than they saved by using it. It wouldn't dissolve properly in the fuel and you would pull the carbies apart and they would be full of oil. personally I think it is what caused my 034 to fail and I was using their synthetic.

hmmmm not quite what i wanted to hear, been running there semi syn 2stroke oil since i got the 7901, no issues so far even with the saw sitting unused for months at a time. always mix up some fresh premium fuel though

 

[porky616]

Unless you tell everyone and get busted!

chinese whispers, more people less chance of the truth! and i drive an excavator so its easy to dispose of squealers

 

[masculator]

hmmmm not quite what i wanted to hear, been running there semi syn 2stroke oil since i got the 7901, no issues so far even with the saw sitting unused for months at a time. always mix up some fresh premium fuel though

I have heard a number of bad stories about penrite oils and after my experience the half litre I have left in the shed will remain unused!

 

[billyj]

was that penrite oils in general or just there 2 stroke/bar oils? ive been using hpr30 in my patrol and commodore before that and been very very happy with the results, patrol has 335,000kms and is spotless under the rocker cover. the good results in the patrol/commy were what lead me to use there 2 stroke and and bar oils

 

[masculator]

was that penrite oils in general or just there 2 stroke/bar oils? ive been using hpr30 in my patrol and commodore before that and been very very happy with the results, patrol has 335,000kms and is spotless under the rocker cover

mostly their 2 stroke oils, which I have seen the results of first hand and of their oil in a mower that had been running fine until it ran penrite oil. I cannot verify the last one but have seen the results numerous timesin the last 18 months in 2 strokes. Pennzoil is a different matter all together and have only ever heard good things about it but I haven't used it!

 

[MCW]

mostly their 2 stroke oils, which I have seen the results of first hand and of their oil in a mower that had been running fine until it ran penrite oil. I cannot verify the last one but have seen the results numerous timesin the last 18 months in 2 strokes. Pennzoil is a different matter all together and have only ever heard good things about it but I haven't used it!

I've seen that in car engines with certain brand name oils that tend to leave a lot of varnish and sludge over time. I've seen guys then change to a better quality oil with far improved detergents etc and all of a sudden a whole heap of garbage starts being let loose throughout the engine. I've never seen it first hand but Castrol GTX2 has a really bad reputation amongst a few mechanic mates of mine for leaving crap throughout an engine and sludge in the sump.

 

[billyj]

mostly their 2 stroke oils, which I have seen the results of first hand and of their oil in a mower that had been running fine until it ran penrite oil. I cannot verify the last one but have seen the results numerous timesin the last 18 months in 2 strokes. Pennzoil is a different matter all together and have only ever heard good things about it but I haven't used it!

might go back to the shell synthetic i used to run in my dirtbike, seemed to handle being ridden hard alot with no probs.

what do you think? heres the write up from shell's site on it

Shell Advance VSX 2

Synthetic based 2-stroke engine oil that offers excellent engine protection and performance compared with mineral engine oils. It is recommended for high performance air and water cooled 2-stroke motorcycle engines.

Is recommended for high performance air and water • Is suitable for oil-injection and premix systems.
Has DPA Technology (Dynamic Performance Additive) response from your bike.
Offers excellent engine protection, cleanliness and low • Prevents scuffing, ring sticking and deposit formation.
Exceeds the international specifications JASO FC, API TC, ISO -L- EGC.

 

[masculator]

I've seen that in car engines with certain brand name oils that tend to leave a lot of varnish and sludge over time. I've seen guys then change to a better quality oil with far improved detergents etc and all of a sudden a whole heap of garbage starts being let loose throughout the engine. I've never seen it first hand but Castrol GTX2 has a really bad reputation amongst a few mechanic mates of mine for leaving crap throughout an engine and sludge in the sump.

I have seen every 2 stroke carby the particular mob I am referring to own pulled apart by our small engine mech and they are all full of oil since they have been using the penrite. They have since given them the flick and gone back to castrol I think. they haven't had the problem since, now it is just the Gimps they use trying to use diesel to mix 2 stroke or the certain brand of fuel that they buy that is high in ethanol that they have had grief with! This is a mob that is running at least 40 2 stroke motors all day every day. when they were running the penrite we would fix at least 5 of them every day and all it took was washing the oil out of the carbies.

 

[masculator]

might go back to the shell synthetic i used to run in my dirtbike, seemed to handle being ridden hard alot with no probs.

what do you think? heres the write up from shell's site on it

Shell Advance VSX 2

Synthetic based 2-stroke engine oil that offers excellent engine protection and performance compared with mineral engine oils. It is recommended for high performance air and water cooled 2-stroke motorcycle engines.

Is recommended for high performance air and water • Is suitable for oil-injection and premix systems.
Has DPA Technology (Dynamic Performance Additive) response from your bike.
Offers excellent engine protection, cleanliness and low • Prevents scuffing, ring sticking and deposit formation.
Exceeds the international specifications JASO FC, API TC, ISO -L- EGC.

Personally I only run castrol 2 stroke oils but I worked for shell and can say that they used to be good.

 

[billyj]

it certainly worked well in my kx125, got over 100hours out of the piston and ring. and probly could have got away with just a new ring when i rebuilt it(rebuild was from gearbox bearing failure)

 

[masculator]

anyway sorry to have sidetracked the thread stihlman i am going to bed night all!

 

[Stihlman441]

anyway sorry to have sidetracked the thread stihlman i am going to bed night all!

No probs mate,maybe we should have a thread for the Ozzys to have yack and talk BS.

 

[isuzurover]

I dont think you can just increase the filter size using the same media and expect it to work to cover greater pressure/verlocities

Ben really needs to step in and school us

Complete "schooling" on filtration may require a 4 year engineering degree

I don't have time for a full explanation now, but - in short:

Filter are NOT sieves. They are constructed of fibres - usually ranging in size from 1-30 microns, with pore sizes of the filter generally much larger than the size of particles they collect.

Particles are (usually) captured due to a combination of inertial collection, interception and diffusion.
This document www.tsi.com/documents/ITI-041.pdf explains the basics.

Particles can "bounce" when they hit a fibre and thereby make their way through a filter, or they can be "reentrained" after capture (less common).

Since filters are not sieves, how well they perform (wrt the above) depends entirely on the filtration velocity (face velocity) - measured as flow rate / face area of the filter. If you keep this value constant, then the filter will operate in the same way.

i.e. - if you have a saw that flows 10 cfm of air at WOT, and a saw that flows 20 cfm of air at WOT, then the latter should have double the filter surface area in order to operate the same. The pressure drop across the filter will in both of these cases then be the same - since the face velocity remains the same.

Hope this helps? I can post more later when I have time.

 

[tdi-rick]

I have seen every 2 stroke carby the particular mob I am referring to own pulled apart by our small engine mech and they are all full of oil since they have been using the penrite. They have since given them the flick and gone back to castrol I think. they haven't had the problem since, now it is just the Gimps they use trying to use diesel to mix 2 stroke or the certain brand of fuel that they buy that is high in ethanol that they have had grief with! This is a mob that is running at least 40 2 stroke motors all day every day. when they were running the penrite we would fix at least 5 of them every day and all it took was washing the oil out of the carbies.

That just sounds like that whoever is mixing the oil isn't mixing it properly ?

Most two stroke oils these days contain solvents to aid mixing and keep the oil in suspension, (particularly the JASO spec ones) but some still don't and the old time race oils didn't and we had to mix and mix and shake just ensure dispersion in the fuel.
I've watched a few people 'mix' their mix and it's been a cursory up and down shake and that was it :msp_rolleyes: