Honing and Chamfering of motorcycle cylinder
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- Опубліковано 17 жов 2024
- In this video I finish the bore job on the Yamaha CT-2 175 enduro by honing and chamfering the ports, checking the piston cylinder clearances and the ring gaps. Honing is done on the Sunnen hone.
Another awesome video…could watch this all day!
Thanks again, watch as many as you want, hopefully you can find some value in these old videos.
Great work. The care and precision is remarkable.
Thank you Aredde, I sure appreciate you following the channel, more to come. Thanks again.
Dale, you got all the coolest, vintage tools, to get the job done right ✅
Thanks Larry, I just like getting it done with old stuff. Stuff my dad would have used. It reminds me of good time with him.
Using the guides as well as stones will keep things squared up better, although setting guides when they are different diameter to stones can be a royal PITA.
Apparently Sunnen make a setting cylinder to 'grind' everything concentric but I've never seen one and always went 'old school' filing them to size and using a scrap cylinder to check for high spots. (or a piece of old steel tube around 3" dia)
You could also have gotten a much better cross hatch .
If your using ball hone to help radius port edges, you need a reversible drill or you only end up doing one side.
From experience, a cordless drill works best, around 100¬200 rpm and a 'fast' stroke
I was teaching people to get within 0.0003" of required size but many with a mechanical aptitude could get 'perfect' results top to bottom (even on the rather long Sportster cylinders, particularly when it was there own))
Yes, you are correct on keeping the stones trued. I use the truing sleeves often during the course of a hone. I normally don't have any problem keeping the taper of the bores within .0002.
I rarely use a ball hone, but you are right, if using to chamfer ports you do need to go both directions to accomplish the task. I prefer the small diamond burrs these days and really can do an entire cylinder in less than five minutes, and think it does a far better job than a ball hone.
@@montana2strokeracer 0.0002" is pretty good, you can allow the top of cylinder to be very slightly tighter as it will expand more than lower section. I tried up to 0.001" which seemed to make a difference but it may have been wishful thinking? Riding open class meant I rarely had too little power. My Maico 490 dynoed at 63bhp
Beautiful job Dale, the Honing Machine is a great peice of kit. It's the same age as my BSA too!
Best wishes, Dean.
Thanks again Dean, I love that old honing machine, the great thing about it is all the stones and scrapers are still available. The machine its self is very tight and does a great job. I use it not just for cylinders but any kind of fine tuning of inside diameter work that may come along, its good from just 1/2 inch up to 6 inches. Im like you. I just like getting things done with old equipment as much as possible, I just think its cool.
great video as always dale great job
Thanks Mark, I sure appreciate your comments and viewership.
Dale, thank you. I have some cylinders that u.s. chrome just did for me. Do I need to chamfer the ports or can I do it with my ball hone that I purchased specifically for nikosil.
Hey Joe, sorry man you are on your own with Nikosil, I'm living in the past before all that fancy stuff. It would be my belief that all that was done before they Nikosiled the cylinder. I understand some folks ball hone to get their crosshatch others just leave it alone. Too new for me. I'm living in the 70's on this channel. Thanks for spending time with me in the shop!
Another Great video, thanks.
Thanks Jeff, I sure appreciate you watchin, and commenting.
Thanks for sharing brother.
You bet, thanks for following along brother
Love the videos and how you've gotten more comfortable doing them. When doing your piston/cylinder stuff can you explain at what point you need to go up in piston size? My TC-125 bore is reading about 55.95mm (top to bottom), the book (clymers) states 56mm and over .05mm difference, then go up to the next size. So I'm guessing I'm good with standard bore. Anything you do on the lathe or mill is definitely a joy to watch.
Thanks for the kind words Greg. I do feel more comfortable as I go along. Your need to bore is basically controlled by 3 things. Damage, Piston to cylinder clearance (wear), and cylinder taper (also wear) Im not sure of your specific tolerances, but if the Piston to cylinder clearance is too extreme to correct with a new piston then it must be bored oversize to bring those tolerances back in line. Same with cylinder taper, if say the top of the cylinder is worn more than the bottom, then boring is required to bring the cylinder back in spec. I think a lot of folks like the machine work as it relates to motorcycles, I can see it in the number of view and the watch time. But there are others that really dont care and wish I would just build another engine. Sure that is ok too, but in reality, you have to fix things or weld bore, and hone before you can build. So its all part of it. Im just trying to show how it all works together. Sure appreciate you following along and your comments.
@@montana2strokeracer Thanks for the info. My cylinder and piston look fine. It's within .05mm so I think I'm good with what's there, or could just get a .05 over and hone a just a bit. Thanks for replying and the content you do.
In my experience, your OK to have up to 0.0055" piston to cylinder clearance on Suzuki 125s, even the RM's.
At 0.006" clearance, the piston slap will eventually break off piston skirt and cause a massive amount of damage, if your lucky it will only need bore, main bearings and seals. (if your unlucky it holes the crankcase)
Haven't seen or heard of a TC125 since the 70's and mainly worked on late 70's through 90's models
@@1crazypj I'm no boring and honing guru, but compression was only reading about 75 psi. I'm told that was good for those engines, but then I got a new std bore cylinder and piston and am still reading the same compression. Maybe that's fine, or I have another issues, not sure yet, since I haven't messed with it much since.
@@gregslair4278 One thing many people fail to do is have throttle wide open or carb removed when doing compression tests. I think the best reading you will ever get is around 90 psi as compression doesn't start until exhaust port closes. It will get significantly higher when motor is 'on the pipe' though
Should I chamfer the piston as well? it has sharp edges
No, the piston is not a problem, the problem is the rings catching in the sharp ports.
If you send one off do they do this?
Most do. I always checked though.
one might think doing a 2 stroke engine is much easier than a 4 stroke with all the cams,valve train etc. but not really true as seen in the work you do. not to mention the dreaded crank case seals.
I dont know Frank, I still think they are less complicated, but you can over think anything and make it complicated. That is one of the thing I had to come to grips with early on. My brain just try to over think everything. It was a problem, now I just dont think about things as much, just jump in and do it.
hear ya, i always over think and worry when doing almost all jobs, its a curse thats hard to defeat. but i often jump in to soon and reget later not thinking it through. example of this is my 1974 honda XL-250 it had 30 pounds of compression so pulled the jug sure enough the rings were stuck. so i rushed out and got a set of rings std size not checking if the piston was over size. well it was .50 over. installed and wondered why the end gap was huge,then i checked the piston found it was .50 over size. story for me is the old carpenter measure twice and cut once.@@montana2strokeracer
im first in line , finally!
Thank you Frank
Here
Dang Cain, you let Frank beat you. Step it up dude