Z1 - Flex Hone for Cylinder Refresh.

I'm trying to find the right size flex hone attachment to put some cross-hatching back in the bores of my stock (66 mm) cylinders before I fit new rings.

I want to use the 'ball' type (as made by Brush Research - silicon carbide /240 grit), as I've used this type before on auto engines with good results. The type that has three stones on sprung arms don't work anywhere near as well as the flex hone units.

The closest that I can find any listing for is a 70 mm. I know this will be a tad on the tight side, but should be OK, properly lubed, for the brief time that it takes to hone a cross-hatch pattern.

Has anyone used this size flex hone in stock Z1 bores with good results?

Is there another manufacturer that makes a flex hone correctly sized for the stock 66 mm Z1 bores?

Doh!

Do your metric/SAE conversions, Tim.

67 mm is 2 5/8 inches. Brush Research make a 2/58" flex hone.

It's getting late. My excuse and I'm sticking with it!

Crisis averted.

In case anyone else needs one ...

www.amazon.com/67mm-Flex-Hone-Cylinder-S...ds=2+5%2F8+flex+hone

I did mine with the tri-stone set up and it turned out great. I would like to see a pic when your done with yours to see the difference.

The dingoball hones are best for used cylinders since they will conform to the wall. Straight hones can skip over spots.

enginehones.com is a good resource. www.enginehones.com/fl2to2.html

I bought a hone for my 750 cylinders that I'll offer up on loan. PM me if you live in the US and want to discuss.

I've been using ball hones in two strokes for 20 some-odd years. They dont get caught in the ports. I soak the cylinder and hone with WD and run it for about 3 seconds, moving it up and down quick enough for a good angle. If you sit with it running in the cylinder too long you will open it up. 3-5 seconds tops.

Kidkawie wrote: I've been using ball hones in two strokes for 20 some-odd years. They dont get caught in the ports. I soak the cylinder and hone with WD and run it for about 3 seconds, moving it up and down quick enough for a good angle. If you sit with it running in the cylinder too long you will open it up. 3-5 seconds tops.

Here is a video on how to use a flex hone... www.enginehones.com/technical.html

FYI: the recommended lubrication is flex hone oil or motor oil.

I've tried other oils but prefer WD for this particular job. Using thinner oils help abrasives cut better. I've used straight mineral spirits on some things, washes away debris.

Besides clamping a piston in a vice, the video looks good.

I've used the 2 5/8 Flex hone on 2 900's and recently bought a 70mm for a 1000 I'm currently working on. I haven't started the 100 yet, but the 2 900's had no problems with ring seating or smoke. I splurged and ordered their oil as well. I think it was 1/2 quart. I've done 3 blocks (12 cylinders) and probably still have 3/4 left.

MDZ1rider wrote: I've used the 2 5/8 Flex hone on 2 900's and recently bought a 70mm for a 1000 I'm currently working on. I haven't started the 100 yet, but the 2 900's had no problems with ring seating or smoke. I splurged and ordered their oil as well. I think it was 1/2 quart. I've done 3 blocks (12 cylinders) and probably still have 3/4 left.

Thanks! I've ordered the 2 5/8 flex hone. In the past I've used good old 3-in-ONE oil as the hone lubricant with good results (It's made by W-D 40). I guess that most lightweight petroleum distillate oils will do the job - you just need to make sure that you use enough of it to soak the 'grit balls' and give the cylinder wall a good covering too.

kaw-a-holic wrote: I did mine with the tri-stone set up and it turned out great. I would like to see a pic when your done with yours to see the difference.

It's going to be a while before I'm ready to hone. I've got to scrape gaskets, strip off PO's paint job, wet-blast and ultrasonic these cylinders beforehand. I'm just getting my ducks in a row. I'm one of those who hates to 'need and not have'.

That's a good philosophy.