crank rebuilding and cylinder boring

newmann wrote:

I didn't ask about porting, just chamfering the ports and relieving the exhaust bridge. That is the most important part of a bore job for an...

I didn't ask about porting, just chamfering the ports and relieving the exhaust bridge. That is the most important part of a bore job for an early CR125M and a step most local machine shops overlook as they are not in the dirt bike business.

19673ontree wrote:

I guess to properly answer your question is I can bore and hone and I have bored several cr125m cylinders this summer if you want port...

I guess to properly answer your question is I can bore and hone and I have bored several cr125m cylinders this summer if you want port chambfered and exhaust bridge cut out relieved you will have to do that yourself ,

newmann wrote:

Fair enough, just let people know that they need to finish the job before they snag a ring or stick a piston and come back complaining...

Fair enough, just let people know that they need to finish the job before they snag a ring or stick a piston and come back complaining to you. I have a bunch of cylinders to be done and just don't have the time to devote to cleaning them all up when they get back from the machinist so I have been looking for someone to do mine. Millenium Technologies has done a dozen plus chrome lined cylinders for me and their work has always been flawless in all respects. They have to relieve and chamfer before any plating is done as it cannot be done after the fact. Has anyone had a cast iron bore done there? Do they chamfer and relieve as required and how much do they charge? Some of us aren't in the market for a $39.95 bore job.

wolfy0067 wrote:

Wow, woke up this morning and this post came to life last night, I wanted to comment , however I am understanding this man makes his...

Wow, woke up this morning and this post came to life last night, I wanted to comment , however I am understanding this man makes his living providing these services.

Here we go, I will just say I've bored a lot of cylinders and learned the correct methods through experience. This I believe is a case of you get what you pay for, and the cylinder seen in the photos will work.

Now to why I asked to see your hone selection earlier, in the last photo you had provided in cylinder boring 101 look close at about 11 o'clock, trained eyes can see the metal smear/chatter from cutting to much metal at one time, you have to look past the cross hatch to see this, when you bore a cylinder and do a quick hone, how do you know the cylinder is perfectly round, I have never seen a cylinder come off the boring bar perfectly straight, it's the honing that get them perfect. that last couple thousands is where you can work out the tapers using a bore gauge, however this takes time.

Again is cost is a factor then this man is provide an economical service to get your bike on the trail. If your building a competition engine where all tolerance are critical, ask Ontree to spend the extra time boring the cylinder to perfection.

I've seen home made hone tanks that work very well with out having to buy a sunnen machine, you will never recoup the investment, little things line prepping the gasket surfaces will ensure your jug is square on the boring jig. Hours can be spent prepping cases and cylinder before any assembly work begins. Respectfully, Wolfy

wolfy0067 wrote:

Wow, woke up this morning and this post came to life last night, I wanted to comment , however I am understanding this man makes his...

Wow, woke up this morning and this post came to life last night, I wanted to comment , however I am understanding this man makes his living providing these services.

Here we go, I will just say I've bored a lot of cylinders and learned the correct methods through experience. This I believe is a case of you get what you pay for, and the cylinder seen in the photos will work.

Now to why I asked to see your hone selection earlier, in the last photo you had provided in cylinder boring 101 look close at about 11 o'clock, trained eyes can see the metal smear/chatter from cutting to much metal at one time, you have to look past the cross hatch to see this, when you bore a cylinder and do a quick hone, how do you know the cylinder is perfectly round, I have never seen a cylinder come off the boring bar perfectly straight, it's the honing that get them perfect. that last couple thousands is where you can work out the tapers using a bore gauge, however this takes time.

Again is cost is a factor then this man is provide an economical service to get your bike on the trail. If your building a competition engine where all tolerance are critical, ask Ontree to spend the extra time boring the cylinder to perfection.

I've seen home made hone tanks that work very well with out having to buy a sunnen machine, you will never recoup the investment, little things line prepping the gasket surfaces will ensure your jug is square on the boring jig. Hours can be spent prepping cases and cylinder before any assembly work begins. Respectfully, Wolfy

19673ontree wrote:

Yep thats true , and a good point , lots out there just like you aceofspades , guys I do a good job on this stuff...

Yep thats true , and a good point , lots out there just like you aceofspades , guys I do a good job on this stuff for the money ive had no problem at all ,,