Follow-up Success on Honing Heavy Scratches - With New Ring & Hone, Compression Up 50

[Stihlofadeal64]

In basketball, this is a "free shot at the goal" with a trashed cylinder.

Some might remember that a month ago, Scotchbrite was the #1 forum suggestion for a scored cylinder. In my view, someone working with a Scotchbrite might allow 3-4 hours, to achieve what the hone did in about 8 seconds, except that the work of the hone is 'true.'

We always have the judgement call of how far to go. The risks of overdoing it are ever present. You don't not want to sacrifice the ring end gap, and the resultant potential loss of compression. Unless you've honed a few dozen or a few hundred, it's a hard call.

You can go in with 180g or 240g. Heck you can bore the cylinder and go back with oversize rings. That usually is cost prohibitive.

What's interesting is that last time this was discussed we had about 60 responses. About 9 out of 10 posters said don't hone - ever! A few posters however reported great success with honing cylinders.

Good post from Wots in Europe. Great job on saving what sounds like 23 pieces of equipment by honing! It would be good to hear from Wots as to what grit hone he uses in the Flex Hone series. Has he used the 3 legged stone hones?

It's interesting that at least one poster has suggested that the honing performed here might not be enough. Maybe so. Maybe not. The real key is how long the repair lasts. Only time will tell.

One great thing about this excellent forum is you get to share experiences with a lot of great guys who have been there and done that. Everyone gets smarter.

The good news is that every time we hone a bad cylinder, we get to use our best judgement. We can hone on to our heart's content, or just to pitch the old on in the trash without even trying. It's a free shot at the goal.:smile2:

I can certainly give you an "A" for articulating your point. Your finds have brought several "closeted honers" to the surface and challenged a long held opinion. Now run your saw for 3 or 4 months and do a recheck on the compression and overall results. It would be great to tear it down and take new pics at that point for a longer term update. It sure is interesting and appears that some long-held ideas about the durability and or thickness of cylinder plating are certainly challenged.

 

[Saw Dr.]

It still looks like some transfer in there to me also.

 

[jropo]

It still looks like some transfer in there to me also.

Good job! Good thread!

If that was my cylinder I would deal w/ a little Noncleanup, than burn through the coating.
If it was a steel/cast bore might as get it all.

 

[hamish]

Get rid of the transfer first of all then by all menas hit it with a hone, the unifirm cross hatch in itself is worth it. Revoving tansfer with a srping loaded hone is a no-no in my books as it is easy to get out of round very quickly. A nice hone such as a Sunnen with its two guide shoes and two stones does a much better job in you intend to remove transfer with it and on cast barrels is a dream tool to bore for oversize.

 

[jropo]

Might I add that a pig rich mix will help w/ break in.
I'd rather fowl a plug than burn up cylinder.

 

[blsnelling]

That remaining transfer must be removed. It should be done by hand, and then finished up with the hone. That remaining transfer is a raised surface area and will only serve to promote further scoring of the new piston. I do not recommend just honing away until it's gone. That's a recipe for ruining the cylinder.

 

[hamish]

That remaining transfer must be removed. It should be done by hand, and then finished up with the hone. That remaining transfer is a raised surface area and will only serve to promote further scoring of the new piston. I do not recommend just honing away until it's gone. That's a recipe for ruining the cylinder.

Exactly that why a hone with guides is required, set your basline accross the transfer side of the cylinder (where 90%+ of the time there is no transfer) and the stones will never cut into the coating of the cylinder, then swap out stones and a light finish hone laid in. In most cases a quality hone will outcost the price of several new oem cylinders, but if you have one..........and its paid for, works wonders.

 

[one.man.band]

+1

glad you had a good result with the hone.

not a fan of using 30w motor oil or transmission fluid. honing oil is more expensive, but i think its worth the extra. the heavier oils hold the metal, a machine shop might sell you or give you a few ounces if you ask nice.

for me cleaning the cylinder before and after honing is as important or more so as honing itself. i use laundry soap, or some other soapy detergent and of clean rags, after a scrub with WD.

hard to convince most that it can be done. i for one, was trying to talk you out of it myself, (without practicing on junked cylinders first) on the other thread.

rep sent.

 

[Wots]

Hi again!

Im writing bit more information because someone sent me a PM with some questions.

------

First- Honing is not black magic or nuclear science! You have 3 materials what are with differenth hardness. Most hardest is Nikasil plating insider cylinder bore,then comes the ball hone material and then most softest is melted AL from pistion. Now think on that the softer material basically dont scratch harder material. So you simpliy you hone what cuts AL and other scrap from inside cylinder bore without damaging Nik plating because hone virtually cant cut it.

Second- All you do really is CLEANING nikasil plating from stuff what have sticked to it. You cant cut nikasil plating for boring it out or giving new cyl diameter because nikasil plating is so thin. If you want to enlarge bore you have to remove nikasil plating,then bore it out and replate the cyl surface with nikasil. Dont confuse nikasil and cast iron/steel cylinder!!

Third- For Stihl cylinders i use Al oxide ballhones. Dont know what grit they are to be honest. Im not at work until after few days. The hone must be bit larger than cyl because then it will selfcenter itself. It must eneter with easy push ,otherwise you brake the hone.

Fourth- If you use ballhone with too large diameter for cyclinder then you start loosing balls and there is a change you ruin something inside your cylinder because little cutting balls start to get stuck in ports etc .

Fifth- Dont think about measuring piston ring gap or somthing. YOU CANT BORE OUT Nikasil cylinder with AL oxide ball hone because it dont scratch/cuts the nikasil!

--------------

Most important thing is that. Honing is only for saving money! You cant improve by honing nikasil cylinder saw performance.

If u get badly scored cylinder get some sandpaper and rub off big chunks of AL . Then give a finishing touch with ballhone. If your cyl is not badly scored then you can skip the sandpaper part.

Many people dont realise if you score your pistion then its actually expanding due extreme heat! Expanding piston means if will push out cylinder perfect roundess and even can make some deep scratches what cant be repaired!

And ALWAYS install new piston because ring grooves are first things what will fail with oiling/lean mixture problem. If u got rings stuck in grooves you still have like zero compression.

-------------

I did my first honing about 1.5 years ago. Ouer customers are mostly companies and they beat the hell out of their saws. So dont be afraid to hone . Honing is not equal to new cylinder but its best bang for buck!
Messing with acid will simply take too much time and then its almost same by the price to put new cyl.

 

[one.man.band]

wots....

i'm not aware of any cylinder re-plating shops that can re-plate a dead end bore cylinder. does anyone know of any?

any honing cuts grooves and folds metal over. cleaning the scratches made by honing is very important in my book. most all machine shops that you bring a cylinder in to be honed, do not clean it for the customer unless they (shop) will be putting the motor back together.

ball hones are sold oversize. when you buy a 50mm hone size for a 50mm cylinder, the hone already sized correctly bigger for a 50mm application.

 

[Wots]

wots....

i'm not aware of any cylinder re-plating shops that can re-plate a dead end bore cylinder. does anyone know of any?

any honing cuts grooves and folds metal over. cleaning the scratches made by honing is very important in my book. most all machine shops that you bring a cylinder in to be honed, do not clean it for the customer unless they (shop) will be putting the motor back together.

ball hones are sold oversize. when you buy a 50mm hone size for a 50mm cylinder, the hone already sized correctly bigger for a 50mm application.

I have heard replating is used for motorcycle/snowmobiles cylinders because they are really exspensive to simply just buy new. Sometimes replating is combined with reparing cylinder when something falls into cylinder or piston pin comes to loose for example.

--

You dont get it. You dont go to machine shop with chainsaw cylinder. Its cheaper to buy Al oxide ballhone and do it youself. All tools what you need is battery drill and some oil for cutting and then cleaning fluid for washing cylinder. Honing scored cylinder is 10min work and after that you can install it back . 80% of time it is washing cylinder because u cant use dirty parts to screw motor together.

---

Even 20-30 seconds doing with ballhone will make cyilinder shining and you can see factory made cross grooves from scored cylinder.

---

Ill do some photos when i get back to work.I have MS250 there,what is 10 years old. Been in a hands of construction company and then got straight gas. The cylinder is honed already but i can show you the picture of piston. And that saw will work atleast 5 year whit same cylinder.

 

[one.man.band]

but, i am in agreement with you wots. would never take a my saw cylinder to a machine shop. mentioned this point for information purposes. not everyone will want to hone a cylinder themselves. if, they have someone else do this for them, at least they know what to expect is all.

i have not heard of anyone getting a re-plated saw cylinder. do not know if this can be done. realize that it is done for MC's. curious to know if any plating shops will do this it is all.

read the other thread, maybe then you will realize i do not discount the benefits of honing as much as you think i do.

stay thirsty.

 

[diggers_dad]

Many posters on this great site may recall our spirited discussion about the pros and cons of 2 cycle cylinder honing about a month ago. The story ends with my saw being back together, running perfectly. Compression is up from 90 to 140. Investment= $28 hone and a $5 ring.

Great info, thanks for the post. I've been thinking about trying this with a "nothing to lose" cylinder.

Rep for ya!

 

[etbrown4]

Based on the number of pm's I've gotten, it seems that a lot of forum members want more information on the ball or flex hones, so here is some info I found on the package of my 320grit flex hone with a few edits:

1. Use 10-30 weight oil or Flex hone hole to oil the hone before entry.
2. Clamp your cylinder in a vice or hold with one hand very firmly.
3. Have the hone rotating and liberally oiled before entering the cylinder, and while removing hone from cylinder.
4. Rotate hone at 500-1200 rpm. Best to use battery drill. Do not use air tools or high speed motors.
5. Use between 1 and 2 'in and out' strokes per second depending on rpm. That is 10-20 'in and out' strokes every 10 seconds. Use faster final stroking 'in and out' to create cross hatch pattern on cylinder wall.
6. Honing time approx. 20-30 seconds per cylinder. (The heavier grits will require much less time) Do no more than what is needed.
7. It is recommended that you check your progress after every 5-10 seconds
8. Do not use solvents for honing or cleanup.
9. After honing, clean cylinder with warm soapy water, using a brush. Wipe clean with dry rag.

(yes, you're right if you noticed that I didn't follow the directions exactly, as I went a little lighter):msp_thumbup:

Here's a really good honing video I posted a month ago: Flex Hone Demonstration Video - YouTube

Here's another video I ran across - it's a real simple instruction - maybe a little too simple, but easy to follow for sure
Motorcycle and ATV Cylinder Hone Instructions - Flex-Hone - YouTube

The people who sell hones can give more advice and can size your hone correctly. They run slightly larger than your bore, based on a chart they have.

good luck and happy honing!

 

[Stihlofadeal64]

Based on the number of pm's I've gotten, it seems that a lot of forum members want more information on the ball or flex hones, so here is some info I found on the package of my 320grit flex hone with a few edits:

1. Use 10-30 weight oil or Flex hone hole to oil the hone before entry.
2. Clamp your cylinder in a vice or hold with one hand very firmly.
3. Have the hone rotating and liberally oiled before entering the cylinder, and while removing hone from cylinder.
4. Rotate hone at 500-1200 rpm. Best to use battery drill. Do not use air tools or high speed motors.
5. Use between 1 and 2 'in and out' strokes per second depending on rpm. That is 10-20 'in and out' strokes every 10 seconds. Use faster final stroking 'in and out' to create cross hatch pattern on cylinder wall.
6. Honing time approx. 20-30 seconds per cylinder. (The heavier grits will require much less time) Do no more than what is needed.
7. It is recommended that you check your progress after every 5-10 seconds
8. Do not use solvents for honing or cleanup.
9. After honing, clean cylinder with warm soapy water, using a brush. Wipe clean with dry rag.

(yes, you're right if you noticed that I didn't follow the directions exactly, as I went a little lighter):msp_thumbup:

Here's a really good honing video I posted a month ago: Flex Hone Demonstration Video - YouTube

Here's another video I ran across - it's a real simple instruction - maybe a little too simple, but easy to follow for sure
Motorcycle and ATV Cylinder Hone Instructions - Flex-Hone - YouTube

The people who sell hones can give more advice and can size your hone correctly. They run slightly larger than your bore, based on a chart they have.

good luck and happy honing!

i'm really surprised that this post didn't get more replies. I got my hone over the weekend, and worked on a a cylinder with it. I was greatly surprised at the effectiveness of what has taken me quite some time to accomplish. I did work with the acid and the hand rub for some time on one cylinder that I had in mind to experiment with. I can say that there are probably more guys out there that want to try this because the recommendations really work.

Otherwise directly after the original post I noticed that the exact hone which was listed and referenced from this thread was immediately sold out. Could it be that I was not the only one who purchased one for this experiment. I desire to thank the OP for the documented information and for those who chimed in. I hope more will post their ideas as well. Thanks