Poorman's guide to Cylinder Repair

[bigbadbob]

I was BSing with the local Stihl mechanic here and he said not to use any type of sandpaper on nicasil as it will leave deposits behind and the new rings and piston won't last. Can anyone confirm this or is it a wives tale. I did it to my 024 but have no run it much.
Bob

 

[Four Paws]

You should ask your Stihl mechanic if he has ever honed a cylinder. If he answers yes, then ask him what the abrasive is that is used on the hone. Chances are it is either aluminum oxide or silicon carbide - the same abrasive used on many sandpapers - He is putting you on. NOW, if you don't wash the cylinder with soapy water after you hone/sand/etc. you will be leaving grit and debris behind that will likely cause your cylinder to wear excessively fast.

 

[RiverRat2]

This is a great thread!!!!

You should ask your Stihl mechanic if he has ever honed a cylinder. If he answers yes, then ask him what the abrasive is that is used on the hone. Chances are it is either aluminum oxide or silicon carbide - the same abrasive used on many sandpapers - He is putting you on. NOW, if you don't wash the cylinder with soapy water after you hone/sand/etc. you will be leaving grit and debris behind that will likely cause your cylinder to wear excessively fast.

Tried to rep you dude but my guns are all empty, wouldn't let me!!! ,,,,,,Great Pix, I have actually never used the acid but have had good luck with fine emory on a wooden dowel rod with Marvel Mystery oil and a bunch of elbow grease,,,,, you are right about the some of the Stihl Mechanics,,, They are trained to sell you a new P/C kit and that is how some of the shops make money.... In their defense it is cost prohibitive to take the time needed to properly prep a cyl with aluminum stuck in it.... They would rather sell you a new P/C or better yet a new saw!!!!!!!!!!!!! But us poor folk got nothin but time on our hands.......

 

[bigbadbob]

You should ask your Stihl mechanic if he has ever honed a cylinder. If he answers yes, then ask him what the abrasive is that is used on the hone. Chances are it is either aluminum oxide or silicon carbide - the same abrasive used on many sandpapers - He is putting you on. NOW, if you don't wash the cylinder with soapy water after you hone/sand/etc. you will be leaving grit and debris behind that will likely cause your cylinder to wear excessively fast.

My thoughts also!!! Nice to have a second opinion.
bob

 

[Lakeside53]

In their defense it is cost prohibitive to take the time needed to properly prep a cyl with aluminum stuck in it.... They would rather sell you a new P/C or better yet a new saw!!!!!!!!!!!!!

Huh? maybe 5 minutes with a ball hone.. or less in most cases.

 

[RiverRat2]

Huh? maybe 5 minutes with a ball hone.. or less in most cases.

I'm talking about using the muratic acid, and the stihl Mechanic @ my local shop just wont take the time, don't know why,,, that just the way he is. Not knocking him thats just his mind set,,, Says he don't want to risk doing all that work and having it come back rather sell you a P/C kit?????????????

 

[Lakeside53]

I often skip the acid part unless the build up is high. Even then, it's only another 5 minutes of total "fill-in"time.... I don't sit there and just watch it fizz!

 

[Four Paws]

you are right about the some of the Stihl Mechanics,,, They are trained to sell you a new P/C kit and that is how some of the shops make money.... In their defense it is cost prohibitive to take the time needed to properly prep a cyl with aluminum stuck in it.... They would rather sell you a new P/C or better yet a new saw!!!!!!!!!!!!!

Wasn't making a generalization about Stihl dealers, or any X-Brand dealer. Just simply saying that Bob was getting lied to, whether intentionally or not. I think good mechanics are a commodity in short supply, and often times the folks hired to do the repair work just don't know the correct answer, procedure, etc. and tales get told that become 'fact'.

Either way, as Andy said, a hone will do the trick every time. Applying muriatic acid is something extra to do that is cheap, and beneficial IMO. Removing the excess aluminum will provide a fairly consistent surface to hone, and will minimize the time you have to hone the cylinder as you aren't scraping the melted aluminum off the exhaust side of the cylinder while you are scraping good nikasil off the rest of the cylinder. And, for some lightly scored cylinders, muriatic acid and a scotch brite will do the trick - no hone needed!

Josh

 

[bigbadbob]

The Stihl guy seemed up front but it was our first encounter, maybe a techie and not a real wrench. I think I owe a thanks to Lakeside for all the info on doing the 024 of mine in Oct. 06. I have played with engines all my life but had never heard of nicasil. As I said I have no run it much but it has 160 compression and you can see the rings are not broken it yet so it may go up a tad. I got the saw from the trash and with the all the help I have a low hour rebuilt 024 for $75 Canadian. And a few other saws now too!!!! Apperently I have a 046 project coming for a 6 pack, more on that later.
thanks again to all it's appreciated.
Bob

 

[andrethegiant70]

In my opinion, most dealers are pretty quick to tell you that your saw is not worth fixing. I know a dealer that doesn't even keep the junk saws for parts. They take up room that he doesn't have and it is way more efficient and cost effective for them to install new parts instead of trying to clean up the old ones with potentially marginal results. I have to say, it makes a lot of sense from the dealer's point of view. Personally, I thoroughly enjoy bringing a non-runner back to life...... but after its all said and done, I think it would be difficult to make a decent wage at it. A used saw just isn't worth the investment in time, unless you get that intangible, non-monetary charge out of it.

 

[1953greg]

will be the next size up

http://www.brushresearch.com/Index.cfm/FuseAction/home.FlexTools/Products/DBC.htm

DBC 2 1/8 use plenty of lube and dont over do it honing, if you have a junk cylinder hit it a lick first to knock the sharp points off of the new ball hone,,,,, oscillating the hone quickly will give you pretty cross hatching and ensure good ring seal/compression. If you dont have real honing oil Marvel mystery oil will work fine, use plently, then wash cylinder with soapy water, rinse good, nozzle air dry, and re lube with your choice of two stroke premix

probably the biggest i would ever need is a 56mm (bb 066) so can i get a 2.25" hone and use it on everything down to maybe 48mm?

 

[Lakeside53]

Fixing old saws... The reality is that at a shop rate of $50-$60 per hour, many aren't economically worth doing, unless you do the work yourself. Most are estimated at 2 hours (everything fixed and tuned up), but it's easy to loose three+ hours in a piston/cylinder/carb/seals/ignition/stripped threads and whatever else is wrong.... I give an estimate for what it's likely to cost - a range, because there is no certainty unless the original reason for failure is obvious - like straight gas. They get two estimates - if the cylinder can be recovered and if not. Most (except on medium->large pro saws) simply choose to trade them in on a new saw. Some take them away, muttering...


Some surprise me and say it's been a great saw- just fix it! $350 fixing an 034S recently... But the customer was really happy, and he has a great saw. Also have a customer that has brought back TWICE in two years a TS350S concrete saw for new P&C, crank bearings, etc, etc .. a complete stripdown and rebuild... About $500 each time, but as he says - it would cost him $1000 for the equivalent new.

 

[Lakeside53]

probably the biggest i would ever need is a 56mm (bb 066) so can i get a 2.25" hone and use it on everything down to maybe 48mm?

It might be a be a bit tight on a 48mm. Just wear it down a little first inside a 2 inch water pipe (takes off the sharp tips), and use a lot of lube. Have it spinning before you push it into the bore.

 

[scottr]

I read on the lawnsite forum where there is a nylon brush hone that has abrasive in the nylon for honing/deglazing . Has anyone used one of those ?

 

[timberwolf]

It was asked earlier about protecting the areas that you don't want etched by the acid. I have found candle wax works well. Put some duct tape securly over the port (from the inside), pour in melted candle wax (from the outside), then remove the tape. Same can be done for the transfers. To protect the head wax can be poured in it, or wax can be applied with a pant brush.

When all done just heat the jug up to clean the wax out.

 

[RiverRat2]

probably the biggest i would ever need is a 56mm (bb 066) so can i get a 2.25" hone and use it on everything down to maybe 48mm?

Greg that may be a bit big, I use a 2 1/8" or 54 MM Silicone Carbide hone on my 066 stuff that is 54 MM bore and it works quite well

48mm works out to 1 7/8" you might need to get one of those for the smaller jugs JMHO