Topic: Loose is better than tight…. No sir it’s just loose

[PeWe]

I found a set of those 65.5 mm pistons cheap on eBay so I had to buy them.
For my K6 old 836 cylinder with wide clearances.
The sleeves sticking out in the cases are even thinner now, 1.25mm.

I think Wiseco 67.5mm pistons in CycleX stepped sleeves also are 1.25mm. A popular set CycleX sold.
(I should remember since I have a cylinder with those sleeves with JE 67mm 890cc I think has 1.5mm thick sleeves where it enter the case.)

The guys in the shop that bored them looked worried before the job, if sleeves could crack. But it went out well.
Same shop bored that cylinder for 836  late 1983

I have not used that set yet.

I made sure to bore a few cylinders while that shop near me still could do it. The mechanic is +70 years old.
The good not much used RC 836 pistons got a cylinder to bore too.

But your pistons are forged JE 65mm (836), a better piston than the old style CycleX 65.5mm piston (849cc) for a  much lower price.
They charged $250US for a set when they had them in stock if I renember correctly.

[CB750R]

Again this is to salvage my poorly machined cylinders for a spare motor. Not to use in my JMR head Carillo rod APE lightened crank motor….


Cyclex has a set of 65.5mm on sale for $100 should I grab them and go slightly larger on my barrelled cylinders.

This is the bore clearance with a 65mm piston.

[PeWe]

Pistons with all rings ?
Find rings to 65.5mm will not be easy.

[Tracksnblades1]

Pistons with all rings ?
Find rings to 65.5mm will not be easy.

Look at Honda CRF230F pistons.. I think standard bore is 65.5mm and a +2mm is 67.5…
Way more modern piston style….but 4 valve reliefs…maybe a wisco with no valve reliefs…?

Anyway check and see what Honda has for rings…

[grcamna2]

So Cycle-x has a set of 65.5mm pistons on sale, anyone have experience with these? Would they be a solution for my loose barrels? I had been under the impression that 65mm was as big as stock sleeves should be pushed… millennium was actually a bit leery of going boring up for the 65mm pistons on the stock sleeves. 

This is only a question for salvaging the barrelled cylinders. I have another set for the $$$ engine build.

How thick are your "barrelled" sleeves on the bottoms ?

? ?

[CB750R]

Pistons with all rings ?
Find rings to 65.5mm will not be easy.

Look at Honda CRF230F pistons.. I think standard bore is 65.5mm and a +2mm is 67.5…
Way more modern piston style….but 4 valve reliefs…maybe a wisco with no valve reliefs…?

Anyway check and see what Honda has for rings…

Same pin diameter as stock rods?

[Tracksnblades1]

Pistons with all rings ?
Find rings to 65.5mm will not be easy.

Look at Honda CRF230F pistons.. I think standard bore is 65.5mm and a +2mm is 67.5…
Way more modern piston style….but 4 valve reliefs…maybe a wisco with no valve reliefs…?

Anyway check and see what Honda has for rings…

Same pin diameter as stock rods?

It was the 65.5mm and oversize rings Honda has available that I wanted PeWe to know about..
The 230’s have a standard three ring piston.. not sure on width but may be the same as the XR’s…
Don’t own either…

Yes, I think pin size is 15mm too, but that may be it..
The 230 is described as a new XR.. I don’t own one. They’re gutless compared to CR/R and CRF/R…..good bike for a wife or youngster that doesn’t want their hair on fire….

[CB750R]

Well my second set of cylinders came back from Millennium today! Look great, might touch up the fins they repaired a bit more.

I also took this time out to send a crank down to APE, oddly enough it arrived back the same day.

Mike sold me one of his stash of balanced rotors so I have a pretty dialed in rotating assembly now!

[grcamna2]

Well my second set of cylinders came back from Millennium today! Look great, might touch up the fins they repaired a bit more.

I also took this time out to send a crank down to APE, oddly enough it arrived back the same day.

Mike sold me one of his stash of balanced rotors so I have a pretty dialed in rotating assembly now!

Did APE exchange the crank you sent to them for one they had ready to go ?
That one looks Ready 
How did the repairs on the fins look which Millennium worked on;do you have a close-up of one of the bores they did ?

[Tracksnblades1]

😳😳😳

Is that the repaired fin in the picture…..?  😳

Dang, my IPad is making it look like it got sand blasted by a commercial sand blaster using black mag or river sand..😳😳😳

Please Tell us the cylinder bores are spot on…🤞

[CB750R]

I’ll follow up on more photos. APE said they had no stock, no cores so shipped out my crank.shipping was not cheap! But it was the last major piece of engine work on my wish list.

[PeWe]

That beautiful crank will get stock rods?
New rod bearings and F2 bolts-nuts?

My K6 runs very even and smooth despite rather high compression and 125-75 cam.
I blame APE for that

[CB750R]

That beautiful crank will get stock rods?
New rod bearings and F2 bolts-nuts?

My K6 runs very even and smooth despite rather high compression and 125-75 cam.
I blame APE for that

Who said anything about stock rods and used bearings!

Carillo Rods and Dynomans JE 65mm F series pistons will be rotating from this crank. I’m running 125-60 cam in the F2 head Mike built for me.

[PeWe]

That beautiful crank will get stock rods?
New rod bearings and F2 bolts-nuts?

My K6 runs very even and smooth despite rather high compression and 125-75 cam.
I blame APE for that

Who said anything about stock rods and used bearings!

Carillo Rods and Dynomans JE 65mm F series pistons will be rotating from this crank. I’m running 125-60 cam in the F2 head Mike built for me.

That's a nice upgrade!

I did not find a shop that could balance a crank for my slow going engine build. It has CycleX Super rods to be mounted.

My K6 got an APE crank with Carillo rods. Also via Mike that helped me with go fast parts.

The "German HD primary chains" another nice detail.
From Classic Cycle City on eBay Germany.
The chains in my K6 has done almost 50.000 km since 2014.
Min power 80whp the first 3 years, then around 90 whp with bigger bore. Late 2020 it breached the100whp wall. 2021 104whp. Late 2022 107whp.
Plenty of torque too. Clutch springs must be the harder type of Barnett with -66- as middle number. For CB500 etc.

The primary chains have not stretched much or anything.
After  around 45000 km, slack was 65.45mm.
I think they were 65.0mm direct after assembly or just a very little less. The first start and ride might have set the chains slack to slightly more. Almost no tension at all.

Earlier in the 80's stock chains slack were 67.5mm after around 35.000km with 836 and almost 80whp. Primary chains service limit is 70.0mm.

[CB750R]

😳😳😳

Is that the repaired fin in the picture…..?  😳

Dang, my IPad is making it look like it got sand blasted by a commercial sand blaster using black mag or river sand..😳😳😳

Please Tell us the cylinder bores are spot on…🤞

Not a coarse blasting but very very clean. Dry feeling. My fine crush glass media doesn’t make it look like this but but doesn’t look as abused as coarse media still very fine surface imperfections that wouldn’t be visible otherwise. I think it may have been baked or stripped chemically. As I have read old cast is very prone to oil soaking and guessing by the weld porosity they didn’t have fun welding the broken fin back on.

This bike was a Mutt when I bought it and will never be a show queen so as long as the motor is tight and the machining is on point I’m not going to loose sleep over this.

I inspected the bores with the dial bore gauge and can’t see any bore deviation. They also surfaced the head as there was 2thou of un even face.

Last photo is of my two sets of cylinders. The darker grey one was the first go around. It’s really interesting to see the same casting flaws in both heads! I wonder how many sets of jugs have that same pattern in the aluminum.

[CB750R]

The casting line I was referring too.

[CB750R]

That beautiful crank will get stock rods?
New rod bearings and F2 bolts-nuts?

My K6 runs very even and smooth despite rather high compression and 125-75 cam.
I blame APE for that

Who said anything about stock rods and used bearings!

Carillo Rods and Dynomans JE 65mm F series pistons will be rotating from this crank. I’m running 125-60 cam in the F2 head Mike built for me.

That's a nice upgrade!

I did not find a shop that could balance a crank for my slow going engine build. It has CycleX Super rods to be mounted.

My K6 got an APE crank with Carillo rods. Also via Mike that helped me with go fast parts.

The "German HD primary chains" another nice detail.
From Classic Cycle City on eBay Germany.
The chains in my K6 has done almost 50.000 km since 2014.
Min power 80whp the first 2 years, around 90 whp. Late 2020 it breached the 100whp wall. 2021 104whp. Late 2022 107whp.
Plenty of torque too. Clutch springs must be the harder type of Barnett with -66- as middle number. For CB500 etc.

The primary chains have not stretched much or anything.
After  around 45000 km, slack was 65.45mm.
I think they were 65.0mm direct after assembly or just a very little less.

Stock chains slack were. 67.5mm after around 40.000km with 836 and around 80whp, maybe a little less. Service limit is 70.0mm

Thanks for looking out for me, Mike supplied me with a set of those primary chains, I have a new HD cam chain, I have all new Honda tensioners, I have an APE clutch kit, I have HD studs… asides from some modifications to the shift dogs I’ve pretty much thrown all the good stuff at this build. Now it’s time to get it buttoned up!

My “still to purchase” list is down to Carbs and Exhaust for bigger ticket items.

[grcamna2]

Did Millennium spray their coating into the cylinders,then machine them all to the proper tolerance ?

[PeWe]

"My “still to purchase” list is down to Carbs and Exhaust for bigger ticket items."

Stock CB750 K2-K6 carbs work fine.

Carbs are not cheap today.
My K6 has Mikuni TMR32 with K&N pods.
Throttle response is very abrupt. A little bit too good.

Hindle 4-2-1:from Ripple Rock Racers in Canada another good upgrade.
I ordered with both long and short baffle just for sure.
I switched to the shorter last year. Not as loud as I thought.

Cruising around up to 120kmh is not too loud. Another thing when using the throttle and gearbox more.
A deeper tone, not sharp and screamy.

[CB750R]

Did Millennium spray their coating into the cylinders,then machine them all to the proper tolerance ?

No I sent them a second set of cylinders. I know that is the method for aluminum bores coated with Nikasil but I don’t think you could do that to an iron sleeve.

[CB750R]

"My “still to purchase” list is down to Carbs and Exhaust for bigger ticket items."

Stock CB750 K2-K6 carbs work fine.
My K6 has Mikuni TMR32 with K&N pods.

Hindle 4-2-1:from Ripple Rock Racers in Canada another good upgrade.

Stock carbs on a MRieck fully built and cammed head?!? Mikes suggestion was as set of RS34
I have a set of the PD carbs as my bike is an F2 (actually I think I now own 5 sets of them…) I don’t know if I want to futz with stock carbs on this setup.

And I have been a fan of Hindle pipes for a long time and super stoked that Ripple Rock and Lang have teamed up to product a lot of cool vintage exhausts. My friend lives right around the corner from RRR in Toronto, and as a Canadian feel somewhat obligated to get a set for my 750.

[MRieck]

"My “still to purchase” list is down to Carbs and Exhaust for bigger ticket items."

Stock CB750 K2-K6 carbs work fine.
My K6 has Mikuni TMR32 with K&N pods.

Hindle 4-2-1:from Ripple Rock Racers in Canada another good upgrade.

Stock carbs on a MRieck fully built and cammed head?!? Mikes suggestion was as set of RS34
I have a set of the PD carbs as my bike is an F2 (actually I think I now own 5 sets of them…) I don’t know if I want to futz with stock carbs on this setup.

And I have been a fan of Hindle pipes for a long time and super stoked that Ripple Rock and Lang have teamed up to product a lot of cool vintage exhausts. My friend lives right around the corner from RRR in Toronto, and as a Canadian feel somewhat obligated to get a set for my 750.

I have to say Millennium could have done a better job on that fin repair. You can get it cleaned up more with a Dremel and some sanding rolls. Are you painting the cylinder black or silver?? I am sure the boring and cylinder bore finish is exactly what it is supposed to. Somebody asked if they can apply Nikasil to iron cylinders.....they can. The hot ticket is to make aluminum sleeves and have those coated.
 I was talking with Kemp from Ripple Rock just last week. He is a great fella to deal with and I highly recommend their products.

[CB750R]

"My “still to purchase” list is down to Carbs and Exhaust for bigger ticket items."

Stock CB750 K2-K6 carbs work fine.
My K6 has Mikuni TMR32 with K&N pods.

Hindle 4-2-1:from Ripple Rock Racers in Canada another good upgrade.

Stock carbs on a MRieck fully built and cammed head?!? Mikes suggestion was as set of RS34
I have a set of the PD carbs as my bike is an F2 (actually I think I now own 5 sets of them…) I don’t know if I want to futz with stock carbs on this setup.

And I have been a fan of Hindle pipes for a long time and super stoked that Ripple Rock and Lang have teamed up to product a lot of cool vintage exhausts. My friend lives right around the corner from RRR in Toronto, and as a Canadian feel somewhat obligated to get a set for my 750.

I have to say Millennium could have done a better job on that fin repair. You can get it cleaned up more with a Dremel and some sanding rolls. Are you painting the cylinder black or silver?? I am sure the boring and cylinder bore finish is exactly what it is supposed to. Somebody asked if they can apply Nikasil to iron cylinders.....they can. The hot ticket is to make aluminum sleeves and have those coated.
 I was talking with Kemp from Ripple Rock just last week. He is a great fella to deal with and I highly recommend their products.

I was trying to be positive about the fin repair but yeah it’s pretty poorly finished. Even worse the one below is just tacked on not even a full pass… it’s going to get the black F bike paint job so will hopefully hide the repair.

I’d like to meet Kemp if I ever get enough Free time when i next visit Toronto. I’ve messaged him a few times and have had an exhaust 1 click away from confirm order probably a dozen times or so… I kinda made it my goal to get my engine done,  and reward is a sweet new exhaust to hang off it!

[PeWe]

Their Hindle 4-2-1 has a very good fit. It is very light. The baffle is a little heavier than the header.

I wondered why pay much for a titan header when I held Hindle pipes.

If carbs/ignition causing bluish pipes, just polish/grind the pipes after carbs/ignition is corrected.
A ride later back to even bronze tone.

Kemp is a nice guy, very helpful.

About the tacked fin. I should fill the repair with JB Weld.

Black engine need constant cleaning. Alu-silver not.

Early 80's, most of us here sprayed our cylinders black. I used wrong paint, for hotter parts like exhaust so it never cured hard and always looked dirty.

[CB750R]

Their Hindle 4-2-1 has a very good fit. It is very light. The baffle is a little heavier than the header.

I wondered why pay much for a titan header when I held Hindle pipes.

If carbs/ignition causing bluish pipes, just polish/grind the pipes after carbs/ignition is corrected.
A ride later back to even bronze tone.

Kemp is a nice guy, very helpful.

About the tacked fin. I should fill the repair with JB Weld.

Black engine need constant cleaning. Alu-silver not.

Early 80's, most of us here sprayed our cylinders black. I used wrong paint, for hotter parts like exhaust so it never cured hard and always looked dirty.

I’ve had/have Hindle pipes on 2 different bikes already. The easiest way to freshen them up is with WD40 and a scotchbrite pad. The tarnish and any baked on grime comes off quite easily and you get back to the raw stainless pretty quickly. Give them a good wash before you fire the bike up and good to go. You can polish them if you want but they always turn that straw color anyway so I didn’t bother on my zrx, and they’re mostly hidden on my zx6r track bike so definitely not a priority.