Japan Meets Britain

LOUD MOUSE · Post by **LOUD MOUSE** » Sun Sep 03, 2017 1:12 pm

Hello Vince.
Any chance for a couple of pics of those pistons?. .........lm

Vince Lupo wrote:Actually I do have a question, if anyone is familiar with the Bore Tech 358cc pistons (Bore Tech is closed for the long weekend, otherwise I'd call them and ask): The pistons don't seem to have a 'direction' in which to install them like the stock Honda pistons (which have an arrow on top indicating which way to install them, plus one side of the top of the pistons looks definitely different than the other). John looked and looked and looked and he can't see any difference between the two sides of the Bore Tech pistons. Does that make sense????

Tim Miller · Post by **Tim Miller** » Sun Sep 03, 2017 1:59 pm

Vince,

I believe Bore Tech uses stock style Pistons that have offset wrist pin bores? If so, the offset goes toward intake side. I would be very leery using Teflon buttons for street application. Drag racing and replacing piston after every run? maybe? But even then I would use C clips.

Tim

Vince Lupo wrote:Actually I do have a question, if anyone is familiar with the Bore Tech 358cc pistons (Bore Tech is closed for the long weekend, otherwise I'd call them and ask): The pistons don't seem to have a 'direction' in which to install them like the stock Honda pistons (which have an arrow on top indicating which way to install them, plus one side of the top of the pistons looks definitely different than the other). John looked and looked and looked and he can't see any difference between the two sides of the Bore Tech pistons. Does that make sense????

LOUD MOUSE · Post by **LOUD MOUSE** » Sun Sep 03, 2017 2:43 pm

I agree with Tim on this Vince.
You have used so many of the SPECIAL engine parts over time and now some are not holding up.
I think you mentioned ENOUGH earlier and I agree with that for you. .........lm

Tim Miller wrote:Vince,

I believe Bore Tech uses stock style Pistons that have offset wrist pin bores? If so, the offset goes toward intake side. I would be very leery using Teflon buttons for street application. Drag racing and replacing piston after every run? maybe? But even then I would use C clips.

Tim

Vince Lupo wrote:Actually I do have a question, if anyone is familiar with the Bore Tech 358cc pistons (Bore Tech is closed for the long weekend, otherwise I'd call them and ask): The pistons don't seem to have a 'direction' in which to install them like the stock Honda pistons (which have an arrow on top indicating which way to install them, plus one side of the top of the pistons looks definitely different than the other). John looked and looked and looked and he can't see any difference between the two sides of the Bore Tech pistons. Does that make sense????

Vince Lupo · Post by **Vince Lupo** » Sun Sep 03, 2017 3:33 pm

Tim Miller wrote:Vince,

I believe Bore Tech uses stock style Pistons that have offset wrist pin bores? If so, the offset goes toward intake side. I would be very leery using Teflon buttons for street application. Drag racing and replacing piston after every run? maybe? But even then I would use C clips.

Tim

Vince Lupo wrote:Actually I do have a question, if anyone is familiar with the Bore Tech 358cc pistons (Bore Tech is closed for the long weekend, otherwise I'd call them and ask): The pistons don't seem to have a 'direction' in which to install them like the stock Honda pistons (which have an arrow on top indicating which way to install them, plus one side of the top of the pistons looks definitely different than the other). John looked and looked and looked and he can't see any difference between the two sides of the Bore Tech pistons. Does that make sense????

Problem with the c-clips is that the wrist pin has moved and forced the wrist pin to one side (the left sides actually). I spoke with Bill Moeller (the Bore-Tech owner and tech) about this and he said that he has seen this happen before, and can be the result of the connecting rods being tapered, and this was the solution that he proposed. So I am relying on the head tech/owner of Bore-Tech who is recommending this -- he said once these are installed I will not have this issue again.

What is the problem with the teflon buttons? Will they not hold up over the long haul? Bill indicated that they would. Actually I'm going to likely call Bill on Tuesday to ask him about the pistons, so I will ask him about the teflon buttons and their longevity.

Vince Lupo · Post by **Vince Lupo** » Sun Sep 03, 2017 3:41 pm

LOUD MOUSE wrote:Hello Vince.
Any chance for a couple of pics of those pistons?. .........lm

I don't think I can get you photos of them this weekend. The bike and all parts are with John. I sent him a note asking him, but being that this is the long weekend, I'm not holding my breath.

Tim Miller · Post by **Tim Miller** » Sun Sep 03, 2017 4:33 pm

It all sounds like a Band-Aid to the real problem. I would be looking into fixing the actual problem. If the little end has taper then it needs to be fixed via. Bushing or replace rod or crank. I was helping a vintage road racer racing CB 77 in GP 350/500 class rebuilding crankshafts and he was trying to running Teflon with very little success it was really eating them up. I would suggest you call any real piston manufacturer and ask them about Teflon buttons?

Peace out,
Tim

Vince Lupo · Post by **Vince Lupo** » Sun Sep 03, 2017 5:19 pm

Tim Miller wrote:It all sounds like a Band-Aid to the real problem. I would be looking into fixing the actual problem. If the little end has taper then it needs to be fixed via. Bushing or replace rod or crank. I was helping a vintage road racer racing CB 77 in GP 350/500 class rebuilding crankshafts and he was trying to running Teflon with very little success it was really eating them up. I would suggest you call any real piston manufacturer and ask them about Teflon buttons?

Peace out,
Tim

Well I actually don't know what the real problem is. John checked for play etc in the crank and it all seemed tight and fine to him (mind you, he does not have specialized equipment to finely check for crank wear, the clearances, wear etc). I am going to call Bill Moeller on Tuesday and talk with him further about these buttons. I will also ask him specifically about their longevity, and if they happen to fail after 2000 miles, then what? Since the pistons, cylinders, wrist pins and now the buttons are all Bore-Tech's, he should know his products better than anyone. I will also talk with my mechanic John about all of this and get some assurances.

This is what often happens when a non-mechanic (me!) relies on the expertise of others -- I'm liable to get differing opinions about what will and will not work, and what is a good and not so good idea. I'm sure if someone asked me about something photography-related, I'd likely give them an opinion that's different than some other photographers.

I will hopefully find out more on Tuesday!