Hone

[muscle]

Ok will these hones found on the Ruff Stuff site (link) work for my bikes? These are 320 grit silicone carbide ball hones.

My first bike is a 98 RM125 with a bore of 54mm (2.126 in) so I need a hone that is a 51mm (2 in)?

And likewise for my 02 YZ250 which is a 66.4mm (2.61 in) so I would need a 64mm (2.5 in) hone?

 

[Ol'89r]

Muscle.

That type of hone works great. I would go with the larger of the two. It will squeeze down to fit the smaller bore and you will only need to buy one hone.

Be sure to use oil as a honing fluid. Don't use solvent since it will disolve the abrasive balls on the hone.

Just my $ .02

Ol'89r

 

[muscle]

Larger of the two? Really? Why does Eric Gore recommend a hone 10% smaller than the bore you are honing? Now I'm a little confused. :ugg:

Is reguler 30 weight motor oil ok for a honing oil?

 

[Ol'89r]

Originally posted by muscle
Now I'm a little confused. :ugg:

That's ok. Im always confused. :confused:

Those hones are very flexable and will squeeze down into a smaller bore if needed. You can buy one for each size cylinder or for as often as you will use it, just get the larger one. The only problem that I have seen with using a larger one is the chance of tearing some of the abrasive balls off in the ports. If your only talking about a difference of a 1/2" , it should'nt matter.

SAE 30 W oil will work. Be sure to wash the bore using hot water and soap after your done honing.

Don't know why Eric recommends the 10% smaller hone but, I'm sure he has a good reason.

 

[Jim Clark]

WD- 40 will work ok according to Brush Research. 10% less is the best. The top of the cylinder is critical,l desire to keep the pressure constant at that point. Run it in and out at a slow rate bathing in WD-40. Be sure to run out the top and back in while rotating. EG recommends Aluminum Oxide but Silicon Oxide at 320 grit works good also, a little cheaper. Travers has them on sell this month. I clean with Simple Green. If you don't have Gordon Jennings book- Two Stroke Tuning, get it will make you a better motor person. Available via Ebay every once and awhile.

JC