Cylinder Honing

[carhartt]

I have a couple of old cylinders laying around. I was thinking of trying to hone some of them. When should you mess with a cylinder and when should you throw it away? How much honing is too much? Always just bought new cylinders and piston and rings.
What are the best hones?

 

[timberwolf]

If you can feel a scratch with you finger nail it is likely too deep to be honed out. Plating on modern saw motors is only a few thou thick at best. Also does not take much enlarging the bore before excess piston clearance becomes an issue.

Save your self some money and just hand dress any problem areas with a little fine sandpaper.

 

[carhartt]

What are you guys using to measure the ID of the cylinder walls?

 

[willsaw4beer]

I.D. mics are handy

 

[timberwolf]

http://en.wikipedia.org/wiki/Bore_gauge

 

[willsaw4beer]

nice, is there an online source that sells those?

 

[Lakeside53]

I fnd measuring the ID is pretty much useless on a modern cylinder. If it's though the plating, its toast. If not, it measures out fine (i.e., it can be used). I have the tools to measure.. never use them... Rings inserted into the bore and measuring the end gap are often the easiest way.


Use AS search on "hones" " honing" etc. many posts and arguements to view..



Snap gauges (the cheapest bore measure) are a PITA, and take some experience to get consistent results.

WWW.mscdirect.com and www.use-enco.com are easy places to see many type of mics.

 

[blsnelling]

You can use a brake hone if you're careful not to catch the ports.

 

[timberwolf]

Lake is righton the money, those tools sit most of the time, only when messing with wildcat saws with parts from different brands and such then it's nice to know. And just like lake said, if the scratch is through the plating it's toast, time you have the scratch out all the plating is gone and the piston flopping about far to loose.

Most automotive specility places will have bore gauges, should be able to find 100 on ebay.

 

[Outlaw5.0]

If you can feel a scratch with you finger nail it is likely too deep to be honed out. Plating on modern saw motors is only a few thou thick at best. Also does not take much enlarging the bore before excess piston clearance becomes an issue.

Save your self some money and just hand dress any problem areas with a little fine sandpaper.

This is correct. You can run the cylinder hone up and down the bore a few times with the proper honing oil just to "clean it up" and put a new surface on the cylinder for the rings. Do not get carried away the coating is only few thou thick as idicated. A quick up and down with the hone twice, will help new rings seal on a old bore.

I have also heard that Jack Roush once said, " you spent 500 miles polishing/seasoning the bore and now you want to hone it!".

 

[timberwolf]

You ever try this on a jug with open transfers? A spring loaded break cyl hone will catch the transfer ports. Also the top portion of the jug will not get as much honing as the lower half leading to a tapered bore.

I would go with a ball hone on cylinders where less than 2/3 of the shoes would be unsupported before brake hone shoe hone types as the honing will be more even and less chance of catching a hone shoe. However any sort of flexible hone will hone more on the leading edge of the hone as it hits the edge of the port.

I am sure skilled hands have saved a few 2 stroke jug with honeing, but would bet far more jugs have been trashed with hones in the hands of less experienced.

 

[Outlaw5.0]

You ever try this on a jug with open transfers? A spring loaded break cyl hone will catch the transfer ports. Also the top portion of the jug will not get as much honing as the lower half leading to a tapered bore.

I would go with a ball hone before brake hone as the honing will be more even. However any sort of flexible hone will hone more on the leading edge of the hone as it hist the edge of the port.

I am sure skilled hands have saved a few 2 stroke jug with honeing, but would bet far more jugs have been trashed with hones in the hads of less experienced.

Oh yes I agree, I'm always guilty of assuming people know how to use hones and tools in general.