Topic: Terry's Kawasaki Mach III 500 build. Let the smoke begin.....

[simon#42]

95 for a set of pistons !   beware not all pistons are equal and good ones are not cheap .

[ken65]

95 for a set of pistons !   beware not all pistons are equal and good ones are not cheap .

i agree. might be cheap cast ones.  they were originally fitted with cast piston but some of those forged ones are a work of art and almost to pretty to hide away inside.

[Terry in Australia]

Thanks guys, I’m using the same pistons in my T350, T500, and I’ve used a couple of sets of their 836cc pistons in my CB750’s without issue. I’ve had Wiseco pistons let me down in the past, so I know that just buying a brand name piston doesn’t guarantee that it’s any good. If I’m wrong, you’re free to laugh at me.

[PeWe]

I guess Cruzinimage pistons.
My CB750 K2 got + 0.50mm F1 version. All piston diameters were equal.

The 2nd set I used for a spare cylinder differ a little so the shop has numbered the pistons were to sit.
The guys at/from the UK Sohc forum often mention CI pistons as frequently used with good result.

Why buy new rings for worn pistons and egg shaped bores that might cause more leak with new round rings?

You can by a complete oversize kit for not much more. Only the bore job that adds on. If tight as it should, result is better.

I have always seen ring change as strange when the used pistons I have are worn in ring grooves, up-down play.

Hondaman wrote in a post recently that bores become egg shaped by wear. New rings will leak more than old that will find its place when back in.
Hone bore round must end up in a too wide clearance.

G-shaped CI wristpin circlips can be replaced by stock Honda to eliminate risk that wristpin push the clip out of groove.

The last bore learned me that +0.50mm will not be enough with flaking rusty sleeves. Had to replace 2 sleeves. +1.0mm pistons had avoided that.

[grcamna2]

I guess Cruzinimage pistons.
My CB750 K2 got + 0.50mm F1 version. All piston diameters were equal.

The 2nd set I used for a spare cylinder differ a little so the shop has numbered the pistons were to sit.
The guys at/from the UK Sohc forum often mention CI pistons as frequently used with good result.

Why buy new rings for worn pistons and egg shaped bores that might cause more leak with new round rings?

You can by a complete oversize kit for not much more. Only the bore job that adds on. If tight as it should, result is better.

I have always seen ring change as strange when the used pistons I have are worn in ring grooves, up-down play.

Hondaman wrote in a post recently that bores become egg shaped by wear. New rings will leak more than old that will find its place when back in.
Hone bore round must end up in a too wide clearance.

G-shaped CI wristpin circlips can be replaced by stock Honda to eliminate risk that wristpin push the clip out of groove.

The last bore learned me that +0.50mm will not be enough with flaking rusty sleeves. Had to replace 2 sleeves. +1.0mm pistons had avoided that.

Very good information Per,thanks. 
I have heard other members on different forums describe that all they needed to do was just 're-ring it' and install new piston rings on the used piston and worn/egg-shaped cylinder bores(I'm not sure they considered what you mentioned here or had a machinist carefully measure the used parts)and I have done what you described with the result that the cylinders did burn oil more than they did before replacing with new rings and honing the cylinders.

I will keep this in mind when considering future 'ring replacements'  rather than getting my cylinders bored to the next oversize with new pistons/rings. 

[Terry in Australia]

Yes and no, honing an egg shaped bore won’t make any difference to ring sealing, if the bores are worn out, they need to be re-bored. I’ve occasionally seen worn out cylinders on CB750’s that had either done big miles or had been poorly maintained, but I’ve re-used many stock sleeves that have cleaned up really nicely with my 3 stone hone, including my K0, Z1-B (bored to 1103 with Moriwaki pistons) T350 and T500.

None of those cylinders were worn out, egg shaped etc. Cast iron cylinders can take a lot of hammering before they’re ready for a rebore, I own an old Repco boring bar here and can bore my cylinders if necessary, but it’s very rare that I have to.

[Stev-o]

95 for a set of pistons !   beware not all pistons are equal and good ones are not cheap .

i agree. might be cheap cast ones.  they were originally fitted with cast piston but some of those forged ones are a work of art and almost to pretty to hide away inside.

+1.  I have forged Wiseco's in both my H1 & H2.  A lot of guys on the Triples forum swear by Wossners [German made] but my machinist is an old school diehard Wiseco guy that uses them in his 1015cc race bike, so I went with them. I like how they have the black ArmorGlide skirt coating.

[grcamna2]

Yes and no, honing an egg shaped bore won’t make any difference to ring sealing, if the bores are worn out, they need to be re-bored. I’ve occasionally seen worn out cylinders on CB750’s that had either done big miles or had been poorly maintained, but I’ve re-used many stock sleeves that have cleaned up really nicely with my 3 stone hone, including my K0, Z1-B (bored to 1103 with Moriwaki pistons) T350 and T500.

None of those cylinders were worn out, egg shaped etc. Cast iron cylinders can take a lot of hammering before they’re ready for a rebore, I own an old Repco boring bar here and can bore my cylinders if necessary, but it’s very rare that I have to.

Many of our vintage bikes are pushing 50 years old;you think they might have been hammered some and need a rebore ?  I like 'round cylinders' for excellent sealing rings and great compression for another few decades of good,solid performance.

[Terry in Australia]

Yes and no, honing an egg shaped bore won’t make any difference to ring sealing, if the bores are worn out, they need to be re-bored. I’ve occasionally seen worn out cylinders on CB750’s that had either done big miles or had been poorly maintained, but I’ve re-used many stock sleeves that have cleaned up really nicely with my 3 stone hone, including my K0, Z1-B (bored to 1103 with Moriwaki pistons) T350 and T500.

None of those cylinders were worn out, egg shaped etc. Cast iron cylinders can take a lot of hammering before they’re ready for a rebore, I own an old Repco boring bar here and can bore my cylinders if necessary, but it’s very rare that I have to.

Many of our vintage bikes are pushing 50 years old;you think they might have been hammered some and need a rebore ?  I like 'round cylinders' for excellent sealing rings and great compression for another few decades of good,solid performance.

Yes Bill, I understand that my 1973 Mach III is 50 years old, and if the cylinders need boring it’s too easy for me to bore them myself, but if they don’t, I won’t.

[grcamna2]

Yes and no, honing an egg shaped bore won’t make any difference to ring sealing, if the bores are worn out, they need to be re-bored. I’ve occasionally seen worn out cylinders on CB750’s that had either done big miles or had been poorly maintained, but I’ve re-used many stock sleeves that have cleaned up really nicely with my 3 stone hone, including my K0, Z1-B (bored to 1103 with Moriwaki pistons) T350 and T500.

None of those cylinders were worn out, egg shaped etc. Cast iron cylinders can take a lot of hammering before they’re ready for a rebore, I own an old Repco boring bar here and can bore my cylinders if necessary, but it’s very rare that I have to.

Many of our vintage bikes are pushing 50 years old;you think they might have been hammered some and need a rebore ?  I like 'round cylinders' for excellent sealing rings and great compression for another few decades of good,solid performance.

Yes Bill, I understand that my 1973 Mach III is 50 years old, and if the cylinders need boring it’s too easy for me to bore them myself, but if they don’t, I won’t.

Terry,I'm sure you're right; 'Back to Basic'.

[Terry in Australia]

Thanks Bill, I’m not frightened of spending money where needed, but I’m not going to waste it if I don’t have to, I had 9 cylinders to choose from and these 3 looked perfect. It’s quite possible that they were bored and not used as they had a coating of grease in them so it might be that someone did get them bored and didn’t use them.

The really good thing is that after paying over $320 USD for shipping, Mitsuo from CI sent me an email to say that he’s refunded me $220 USD, so if I need yet another set of pistons to match the cylinders I’ll be using I know he’s not going to screw me with shipping.

[grcamna2]

Terry,I like what you shared about the nice set of cylinders you have;would like to see a set of H1 cylinders of that quality. Do you have any pictures of them ?

[MauiK3]

Sometimes I think shipping is a racket.

[Terry in Australia]

The trouble with CI is that they have an automatic shipping calculator that you can’t really bypass when you create an order. I do remember in hindsight that this has happened before and Mitsuo seems like a good guy, so I’m not fussed that he’s inadvertently overcharged me, now that the money is back in my account.

[Terry in Australia]

Well it's been an interesting day. This afternoon I sneaked off early while "Working from home" and picked up my beautiful wheels with the new Stinko tyres. I think they look magnificent.

Mach III wheels 14 Mar 2023 by Terry Prendergast, on Flickr

Fearing that Felix and Leo will take turns pissing on them, I stored them up off the ground so the little baastards can't reach them.

Mach III wheels 14 Mar 2023 1 by Terry Prendergast, on Flickr

I sent Dion a pic, and discovered that he's just scored a bloody H2 750! Baastard! Not really, we're good mates. He told me that he needed to move his 1969 H1A to make room for it, and before I knew it, we agreed to swap my blue F2 for it. I'm more than happy with that deal, the H1A is around 90% complete (I admired it when I went to collect my Mach III's a few weeks ago) the frame has been powder coated, tins painted, engine vapor blasted and professionally rebuilt, etc. It's not quite complete though, missing the lower triple clamp, seat, left sidecover and blinkers. He doesn't have a complete exhaust system either, but I'll just buy some new expansion chambers as I'm not too worried about it being 100% original. If I can find the missing exhaust parts along the way, better still.

I'm happy to locate the missing parts (I'll contact Keith Davis in the US and see what he can find for me) and will probably finish it before I finish the '73 H1-E. I think I've become a H1 hoarder. Strange days, indeed.

[ekpent]

Ooooh 69, that's a fast one. I remember when I used to read along on Rick Brett's triple forum when it was a going thing about early 'Bridgeport' cylinders that they coveted. What the heck are they ? You quickly have gone from 0 to 3 but might be a wise move to get them when you can especially with your skills.  Hang in there long enough Terry and that 750 will be yours also.

[Stev-o]

Ooooh 69, that's a fast one. I remember when I used to read along on Rick Brett's triple forum when it was a going thing about early 'Bridgeport' cylinders that they coveted. What the heck are they ?

Great trade Terry, the '69's are highly collectable and very valuable. Hardly ever see them for sale here in the U.S except with a very high sales price.

Eric - there is a divider in the middle of the port it is "bridged", all '69's should have them as well as some early '70 models.

http://3cyl.com/mraxl/partid/cylinders/1969_h1_bridgeport.jpg

Early H1's would also have "windowed" carbs...

http://3cyl.com/mraxl/partid/carb/windowedH1.jpg

Terry - if your bike has both these you have certainly hit the jackpot! I'm amazed that your mate is trading this for a SOHC.

BTW - the wheels look magnificent...

[MauiK3]

Alloy rims! Very nice.
I've often thought about building a set of alloy rims for the K3 and putting them on, would be expensive after buying a set of hubs, spokes, etc. Might be worth the weight savings.
Keep the "steelies" just for originality, put them away in the attic.

Really looking forward to seeing this smoker on the road.

[ekpent]

Ooooh 69, that's a fast one. I remember when I used to read along on Rick Brett's triple forum when it was a going thing about early 'Bridgeport' cylinders that they coveted. What the heck are they ?

Great trade Terry, the '69's are highly collectable and very valuable. Hardly ever see them for sale here in the U.S except with a very high sales price.

Eric - there is a divider in the middle of the port it is "bridged", all '69's should have them as well as some early '70 models.

http://3cyl.com/mraxl/partid/cylinders/1969_h1_bridgeport.jpg

Early H1's would also have "windowed" carbs...

http://3cyl.com/mraxl/partid/carb/windowedH1.jpg

Terry - if your bike has both these you have certainly hit the jackpot! I'm amazed that your mate is trading this for a SOHC.

BTW - the wheels look magnificent...

Thanks for that great explanation Steve. Never delved into that and a picture is worth a thousand words. Hope Terry has some of the goodies !

[Terry in Australia]

Thanks guys, I was surprised that Dion was happy to make a trade like that too, but I’m not gonna look a gift horse in the mouth, as my old grandpappy used to say. (I think he said that, or maybe I saw it on Mister Ed)

Yep, over here they’re particularly rare, and if you think they’re expensive there, they’re totally unaffordable here, I admire Trevor from Warragul’s original H1-A whenever he posts a pic here, and apart from maybe one or two others that I’ve seen for sale for Z1-K0 prices, I never see any out on the road.

I was really struggling with what to do with the blue F2, I’ve had it advertised on Facebook marketplace for what I think is a fair price, but so far it’s only attracted low ballers and old fcukers who want to reminisce about when they had one, but no money, honey. I’d just about decided to keep it, but I’m more than willing to do the red paperclip thing and trade it up, the H1-A “Widow Maker” will be a keeper, and once the H1-E build is done I might start looking for a H2 in need of a good home….

[Terry in Australia]

Ooooh 69, that's a fast one. I remember when I used to read along on Rick Brett's triple forum when it was a going thing about early 'Bridgeport' cylinders that they coveted. What the heck are they ?

Great trade Terry, the '69's are highly collectable and very valuable. Hardly ever see them for sale here in the U.S except with a very high sales price.

Eric - there is a divider in the middle of the port it is "bridged", all '69's should have them as well as some early '70 models.

http://3cyl.com/mraxl/partid/cylinders/1969_h1_bridgeport.jpg

Early H1's would also have "windowed" carbs...

http://3cyl.com/mraxl/partid/carb/windowedH1.jpg

Terry - if your bike has both these you have certainly hit the jackpot! I'm amazed that your mate is trading this for a SOHC.

BTW - the wheels look magnificent.

Thanks Steve, and interestingly the cylinders I’m putting on my H1-E are those “Bridge port” ones in the pic! I only chose them because they had immaculate bores, being a Mach III noob I wouldn’t know a bridgeport cylinder from a hole in the ground, but they’re currently at the vapor blaster’s, and when they come back I’ll post a pic.

[Terry in Australia]

Well the parts for the build are slowly rolling in, a new pair of fork tubes arrived from England yesterday. Look to be very good quality, and I was impressed with how quick they arrived considering how slow international shipping is. I think there’s a set of fork seals in one of the tubs of parts Dion gave me, so as soon as the top plugs arrive from CI I’ll rebuild them and polish the alloy lowers. It’ll be nice to have a rolling chassis to plonk the engine into, eventually.

[Trevor from Warragul]

his 1969 H1A

The 1969 and 1970 are H1. H1A is 1971, H1B is 1972, etc.

A 1969 H1 is highly desirable! I remember when H1A's were seen as the "red headed step-child" of the 500 triples range. I went for a ride on the H1A yesterday. They definitely like the cooler days...

[grcamna2]

his 1969 H1A

The 1969 and 1970 are H1. H1A is 1971, H1B is 1972, etc.

A 1969 H1 is highly desirable! I remember when H1A's were seen as the "red headed step-child" of the 500 triples range. I went for a ride on the H1A yesterday. They definitely like the cooler days...

I'd love to have a 69-70' H1 ! Do the 69' & 70' both use the same exact specs with regard to design features ? Like the bridge ports,etc. ?

[Trevor from Warragul]

If I can find the missing exhaust parts along the way, better still.

If you can make your way out to Warragul, I have a set of pipes you can have. The headers and pipes are separate on the H1 and H1A. The left hand pipe is very ordinary (massive battery stains and peeling chrome), the right hand pipes are okay. The headers come with the collars. I bought a used set from the UK decades ago, and only needed the left side one.