Marky Mark
Hell's Kitchen Trapper
Here are some pics of a saw I am having problems with. I had some work done to it and I am trying to determine if this is causing it. It just doesn't run right.
Piston problems
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Marky Mark
Hell's Kitchen Trapper
Here's a better shot.
Marky Mark
Hell's Kitchen Trapper
Is it me or am I seeing things.
johncinco
Addicted to ArboristSite
Hey heres a new contest. Worst piston damage. heres my entry.
max2cam
ArboristSite Guru
Do you mean that image of Jesus on the cylinder wall holding an 088?
Nah, you're not seeing things, I see it too...
<p>Howdy<p/>
<p>It looks as though to me that piston may have had some previous issues, which may have caused a problem when run hard after being rebuilt. That small hole under the ring grooves is to lubricate the exhaust lip and rings? I've seen that done in the bigger Mac saws to lubricate the exhaust bridge but never on a modern saw like the 2100 ( work with me here). It's ok to re-install a piston that has been slightly marked up, as long as you create diagonal scratches across the marking with some 320 grit emery cloth so the scratches will hold and pin oil to the cylinder wall as the piston moves up and down. We do this to our landing saws and it makes the saws that much harder to blow up the next time, but we also tune them down a bit so the landing guys can't attain the kind of RPMs that most "professional" users can with a regular saw. It does look from the appearance of the cylinder wall that the saw was either tuned lean, or had lean or old gas run through it, or had an air leak somewhere. How do the case seals look? Are the seal seats scratched? Was there a cylinder base gasket?<p/>
<p>It looks as though to me that piston may have had some previous issues, which may have caused a problem when run hard after being rebuilt. That small hole under the ring grooves is to lubricate the exhaust lip and rings? I've seen that done in the bigger Mac saws to lubricate the exhaust bridge but never on a modern saw like the 2100 ( work with me here). It's ok to re-install a piston that has been slightly marked up, as long as you create diagonal scratches across the marking with some 320 grit emery cloth so the scratches will hold and pin oil to the cylinder wall as the piston moves up and down. We do this to our landing saws and it makes the saws that much harder to blow up the next time, but we also tune them down a bit so the landing guys can't attain the kind of RPMs that most "professional" users can with a regular saw. It does look from the appearance of the cylinder wall that the saw was either tuned lean, or had lean or old gas run through it, or had an air leak somewhere. How do the case seals look? Are the seal seats scratched? Was there a cylinder base gasket?<p/>
Another thing to look for too is if the port openings have been beveled well enough on the cylinder wall. It's just like when you dress freshly machined components down with emery cloth and oil when rebuilding the engine in your car, but a Dremel tool works better and faster in a saw cylinder if you have a steady hand and some good bits. And then sand everything by hand to finish it up.
sedanman
Just cut the piano!!
Jacob J, I suspect this was a "professional hop up" that went wrong. The problem with dealing with a engine builder who knows the value and scarcity of particular parts is that you may get "less than desireable" parts back in an engine you paid good money to have tweaked. Sadly this scenario plays out all too often. Dealing with someone face to face raises your chances of getting a quality job. Dealing with someone on the oposite coast tend to give them a license to screw you. Caveat emptor!
<p>Howdy Sedanman<p/>
<p>My only issue with people that "hop-up" saws is when they don't use base gaskets. Yes, I know that an-aerobic RTV and liquid gold and all those other liquid gasket makers do an adequate job in most applications, but the case halves on modern saws don't always match up very good. Combine that with flaws in the base of the cylinder and you've got an air leak waiting to happen. I know removing the base gasket is a way to raise compression but there are still materials, like sheet copper and brass, that are very, very thin and would still make a much more adequate gasket than Red RTV or whatever.<p/>
<p>As far as people on opposite coasts ripping others off, that could be a problem, but I doubt it is here. All of the saw builders mentioned in this forum on a regular or semi-regular basis are all good guys, and will bend over backwards to correct a problem, if it is brought to their attention.<p/>
<p>My only issue with people that "hop-up" saws is when they don't use base gaskets. Yes, I know that an-aerobic RTV and liquid gold and all those other liquid gasket makers do an adequate job in most applications, but the case halves on modern saws don't always match up very good. Combine that with flaws in the base of the cylinder and you've got an air leak waiting to happen. I know removing the base gasket is a way to raise compression but there are still materials, like sheet copper and brass, that are very, very thin and would still make a much more adequate gasket than Red RTV or whatever.<p/>
<p>As far as people on opposite coasts ripping others off, that could be a problem, but I doubt it is here. All of the saw builders mentioned in this forum on a regular or semi-regular basis are all good guys, and will bend over backwards to correct a problem, if it is brought to their attention.<p/>
sedanman
Just cut the piano!!
Right!
sedanman
Just cut the piano!!
The Emporor is NAKED!
Think about this statement.
Think about this statement.
Fish
Tree Freak
Since this thread is an attempt to dog another forum member
here, let us at least gather a little bit of data and backround
about this piston in question. Let us hear from both parties
involved, and what caused the damage, dirt or lean seizure/ or
lack of lubrication. And lets keep it involved with posters
who have a clue with what is being discussed.
I personally don't care about the outcome, but I just enjoy the
ride.
I love you guys, I mean it really
here, let us at least gather a little bit of data and backround
about this piston in question. Let us hear from both parties
involved, and what caused the damage, dirt or lean seizure/ or
lack of lubrication. And lets keep it involved with posters
who have a clue with what is being discussed.
I personally don't care about the outcome, but I just enjoy the
ride.
I love you guys, I mean it really
sedanman
Just cut the piano!!
Looking at this piston I see a scored piston that was cleaned on a wire wheel then installed in a saw. If I'm wrong, PROVE IT! If I sent something out to be "power tuned" and got crap like this back, I'd be hopping mad. If this saw needed a piston and cylinder before modifications were made, that should have been disclosed and the customer given the choice on whether to proceed.
I am now bowing out of this pi$$ing match, I have d said my peace, let the chips fall where they may.
I am now bowing out of this pi$$ing match, I have d said my peace, let the chips fall where they may.
Ok I know I am not the brightest bulb in the light but I am really lost on this one. Is this supposed to be a piston and jug that came from a saw that built my a member and then was sold as good. If it was then that is an issue that should be addressed by the builder. If this is a joke then somewhere along the way somone should say that. People who are considering sending out a saw to be modified might see this and think twice not knowing if this is a joke directed at Mike Rupley or not. Like I said before I am lost and would like to know what is actually going on.
Please inform me.
Just my random thoughts,
Bill
Please inform me.
Just my random thoughts,
Bill
The meark on the piston loks like a peckar track from a porting tool. I am not sure why, but the piston also appears polished. BTW I have had ealings with mike and he treated me right, I have no idea whats going on in this case.
jokers
Addicted to ArboristSite
Brian, thanks for sharing your opinion with us, atleast we know that this isn`t all tongue in cheek and I take from your response that you have more info than was presented here. I`m waiting to see what Mike has to say also but then we also have to consider the "chain of possession" with this saw and although I sincerely don`t want to point a finger at Mark or anyone else, we may not know of all tinkering that has occured with this saw. I can`t claim to have a long relationship with Mike to be able to vouch for his credibilty but I have dealt with him a couple of times and things went very well, and Ken Dunn who I trust from experience has had nothing but good things to say about either of the Rupeleys. I didn`t get the feeling that he has any trust issues with Mike and his standards of workmanship are high so I don`t expect that he would be saying good things about Mike if this were Mike`s typical way of doing business. I want to give Mike the benefit of the doubt and I`m waiting to see how this story unfolds.
Russ
Russ
It's hard to tell much by a picture.
That said, were the rings or one of the rings broken? If not, why not? The top land has a mark like the ring was driven into it on the downstroke.
That said, were the rings or one of the rings broken? If not, why not? The top land has a mark like the ring was driven into it on the downstroke.
Gypo Logger
Timber Baron
Being the chainsaw meadiator that I am, my take on the whole thing is that if we have a problem with a saw purchased or built by another forum member, then it should not be discussed in mixed company, but rather directly with the individual concerned.
Discussing such problems does damage to both partys. First of all, others will avoid doing business with the complainant for fear of problems and others may second guess the sawbuilder in the future.
Things dont always go according to Hoyle, but trying to stop a rumour is like trying to unring a bell.
Mike is a good builder, racer and person as well, and I dont think the original poster intended any malice.
Did anyone hear me complain when Fish powertuned my Poulan Wild Thing, and the saw blew up into tiny piece like so much shrapnel, Nooooooo, you didnt and why would you? Because Fish is my friend and I would never say anything bad about him or his saws.
John
Discussing such problems does damage to both partys. First of all, others will avoid doing business with the complainant for fear of problems and others may second guess the sawbuilder in the future.
Things dont always go according to Hoyle, but trying to stop a rumour is like trying to unring a bell.
Mike is a good builder, racer and person as well, and I dont think the original poster intended any malice.
Did anyone hear me complain when Fish powertuned my Poulan Wild Thing, and the saw blew up into tiny piece like so much shrapnel, Nooooooo, you didnt and why would you? Because Fish is my friend and I would never say anything bad about him or his saws.
John
Sometimes 80 year old men want 25 year old nymphomaniacs. If they get them they don't know how to treat them and then yell "she's only after my money!"
The saw was running top notch when it left here. I offered a full refund for return of the saw and was rejected. I offered, and still will offer, repair of the saw, even though it has been taken apart and I don't know what went wrong.
Sedanman and Rocky you will never make good judges because you make your decision before hearing both sides of the story.
I don't believe futher participation in this thread will accomplish anything. People that believe in me will continue and those that don't will not be swayed. If you feel my saws are not much, I would invite you to the Clearwater meet. There you can see them in action, run by the owner.
Mike
The saw was running top notch when it left here. I offered a full refund for return of the saw and was rejected. I offered, and still will offer, repair of the saw, even though it has been taken apart and I don't know what went wrong.
Sedanman and Rocky you will never make good judges because you make your decision before hearing both sides of the story.
I don't believe futher participation in this thread will accomplish anything. People that believe in me will continue and those that don't will not be swayed. If you feel my saws are not much, I would invite you to the Clearwater meet. There you can see them in action, run by the owner.
Mike
sedanman
Just cut the piano!!
I'd like to see you run THIS ONE, not one of yours.
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