Topic: What did you do to your non-SOHC4 motorcycle today?

[Terry in Australia]

Sometimes God looks after his sinners. I saw a 1981 Kawasaki GPZ1100 B1 going for cheap on FB MP and told myself I didn't need another bike, hell, I'm supposed to be thinning the herd! Well I have sold 2 bikes this year, but anyway, a week or so later, I saw the same red GPZ1100 going for $500 less! Bloody hell, I can't understand why nobody jumped on this when it was first advertised?

So I contact the seller with a lowball offer, and he tells me that I'm offering close to what he'll take, but a couple of guys have offered to swap him various bikes for the GPZ, so he wants to look at them first. I wish him good luck, and assume that I've missed out. The following Thursday I see that he'd left me a message on Tuesday, so I presume it's to tell me it's sold, but to my surprise he comes back with a counter offer, and I accept. The rest, as they say, is history.

GPZ1100 Saturday 28 June 2025 by Terry Prendergast, on Flickr

It hasn't been run since 2013, and apparently has an electrical issue, but he can't remember what the issue was. Spotty and I hauled it home and we had to throw a battery at it and squirt some brake cleaner into the pod filters on the CV carbs (was originally fuel injected) and it fired, so we'll give it an oil and filter change before we try to start it in earnest, on Saturday. I'm looking forwards to taking it for a decent ride.

GPZ1100 Saturday 28 June 2025 1 by Terry Prendergast, on Flickr

[BenelliSEI]

Terry….. No surprise, sometimes they “just find you”! Nice choice!

[grcamna2]

Terry….. No surprise, sometimes they “just find you”! Nice choice!

No fuel injection?
Carbs(what size/model?)seems like a great solution.

[Kelly E]

I would have real trouble passing on that bike. Nice score.

[Terry in Australia]

Thanks guys, I’m stoked. Big Kawasaki’s of the era in near original condition are still worth good money here in Oz, so I had to pick it up for what he offered it to me. The weather plays a big part here, winter is the worst time to sell a bike, but while I wasn’t really looking for another project, I couldn’t say no.

The fuel injection on the first year GPZ1100 was problematic, so converting them to carbs was common. I’m guessing that the carbs are probably Suzuki GS/GSX 34(?)mm items. I’ve got some 33mm Mikuni smooth bores in a box somewhere in my garage that might go on it, but if the CV’s are working ok, I probably won’t bother, as I like the light throttle with CV’s.

The tank has some rust in it which worries me a bit, I’ll try washing it out with phosphoric acid, and line it if necessary, I’m hoping that I won’t have to weld up any holes. Apart from that, I’ll replace the clubman bars with some superbike bars, put some new tyres on it, and replace the rusty exhaust with another one I have here, with a NOS Moriwaki muffler that I have in another box somewhere in my garage. I’m not going to restore it, just clean it up, touch up the black paint and ride it. It’s survived this long in pretty presentable condition, so doesn’t need a ground up restoration.

[grcamna2]

What type of filters will you run Terry?
I see those little,tiny 'cones' on it..

[Terry in Australia]

What type of filters will you run Terry?
I see those little,tiny 'cones' on it..

To be honest I haven't thought much about them Bill, apart from the fact that I was surprised that it had pods on it, because usually CV carbs don't work at all with pods, so I'm assuming that a PO (not the guy I bought it from, he never rode it) has installed a jet kit. While typing this I remembered that I have a Dynojet kit for a Suzuki GS1000/GSX1100 in another box somewhere in my garage, just in case it runs like crap. If I can find an original airbox I'd probably have to modify it significantly to adapt it to the carbs (keeping in mind that the original bike came with EFI, or DFI as Kawasaki called it, so theres no guarantee that it would bolt right up to carbs that it wasn't designed to fit) so I'll probably have to contine with pods. For the time being I'll just concentrate on getting it running, and will work on improving it afterwards.    

[grcamna2]

What type of filters will you run Terry?
I see those little,tiny 'cones' on it..

To be honest I haven't thought much about them Bill, apart from the fact that I was surprised that it had pods on it, because usually CV carbs don't work at all with pods, so I'm assuming that a PO (not the guy I bought it from, he never rode it) has installed a jet kit. While typing this I remembered that I have a Dynojet kit for a Suzuki GS1000/GSX1100 in another box somewhere in my garage, just in case it runs like crap. If I can find an original airbox I'd probably have to modify it significantly to adapt it to the carbs (keeping in mind that the original bike came with EFI, or DFI as Kawasaki called it, so theres no guarantee that it would bolt right up to carbs that it wasn't designed to fit) so I'll probably have to contine with pods. For the time being I'll just concentrate on getting it running, and will work on improving it afterwards.    

Modified airbox ?  

[Stev-o]

I saw a 1981 Kawasaki GPZ1100 B1 going for cheap

Nice score, Terry.  That will be one fast bike once you get it running properly.

I had the little brother, GPz550 and thing screamed! 

[Terry in Australia]

I saw a 1981 Kawasaki GPZ1100 B1 going for cheap

Nice score, Terry.  That will be one fast bike once you get it running properly.

I had the little brother, GPz550 and thing screamed! 

Thanks Steve, yeah it was a great pickup, I checked the odometer yesterday and it's only done 60,000 Kilometres, or around 35,000 miles, so as long as it's been maintained before it went off the road in 2013, the engine and gearbox should be fine. I'm really looking forwards to taking it for a scoot.

[Alan F.]

This afternoon I swapped my spare wheel set onto my Interceptor 650. I'll finish wearing out these used stock tires before going back to the 50/50 Shinkos.

[Stev-o]

Pulled the rear wheel off the Z1.  Seems odd to me, rode it a couple weeks ago, no issue. Then last week I noticed it was flat...WTF?  I guess lucky it didnt go flat during the ride.



Cleaned it up and ordered a tube.

[grcamna2]

Pulled the rear wheel off the Z1.  Seems odd to me, rode it a couple weeks ago, no issue. Then last week I noticed it was flat...WTF?  I guess lucky it didnt go flat during the ride.



Cleaned it up and ordered a tube.

Something went through the tire?
or just a bad tube ?

[Terry in Australia]

Being the good father that I am, yesterday I washed my youngest boy's Royal Enfield Continental GT650. Well, I kinda had to, because the previous day I blew up my little Chinese air compressor, so I had a look for a cheap replacement on FB Marketplace. I found a much nicer one for $90 nearby, so when I brought it home I managed to overfill the compressor oil, and when I fired it up, it sprayed oil out of the breather, all over my boys bike. Ooops..

Oh well, it gave me the opportunity to take it for a couple of laps around the block to dry it off afterwards. Incredibly, after sitting in my patio for 12 months or more since it last ran, it fired right up and ran perfectly, as if it had only been started the day before. I used my new(to me) compressor to pump up the tyres, and booked it in for it's second service, it's only done a couple of thousand miles since 2019 when my son bought it new. It's a good looking bike, especially when just washed.

Royal Enfield Thursday 24 July 2025 1 by Terry Prendergast, on Flickr

[BenelliSEI]

Terry…. Good looking machine. Seat looks a bit hard?

[Terry in Australia]

Terry…. Good looking machine. Seat looks a bit hard?

Thanks John, I think that it's probably a bit firm, but from the couple of rides that I've done, I can't remember being annoyed by it. It's a great bike, and eventually it'll be mine, as my son wants to swap it for my Harley Sportster. S&S make big bore kits and hot cams for them, so when it's officially mine I'll install an 850 kit and cams, and some louder pipes, and it'll be a great ride.

[Terry in Australia]

On the weekend, Spotty and I removed the head from the GPZ1100 to see why there's no compression in cylinders 1 and 2. I was hoping it wasn't anything seriously expensive, and was happy to discover that it was only the head gasket had blown between 1 and 2. Woohoo!

GPZ1100 Saturday 26 July 2025 by Terry Prendergast, on Flickr

The good thing was that I found these high comp pistons lurking inside, which may have been the reason that the original gasket blew.

GPZ1100 Saturday 26 July 2025 1 by Terry Prendergast, on Flickr

I drove back to my place and ratted through my tubs of Kawasaki parts left over from my previous Kawasaki builds. I found a NOS KZ1000 copper gasket, but of course the bores on a KZ1000 are only 70mm, whereas the GPZ1100 bores are 73mm. Hmmnn, well it's easier to make holes bigger than smaller, so I drove over to the hardware store and bought a drum sander attachment for Spotty's drill. I laid the old gasket over the new gasket, and using a sharpie, traced the cylinder OD's from the blown gasket to the new copper gasket, then spent an hour or two enlarging the cylinder holes.   

The next day I finished enlarging the holes in the copper gasket, then gave it a nice thick coat of copper spray, and after cleaning both the head (that Spotty had scrubbed clean with brake cleaner and a wire brush) and the cylinder block gasket mating surface, before putting the gasket in place, then torqued the head down in three stages, 15/25/35 pounds feet. We reinstalled the cams and checked the valve timing, fitted a new cam cover gasket, and the cam cover. On Saturday we'll reinstall the carbs, exhaust, oil cooler and coils, throw some fuel into the tank, and hopefully fire it up. I'm looking forwards to getting it roadworthy and on the road legally, it'll be a fun bike.

[grcamna2]

On the weekend, Spotty and I removed the head from the GPZ1100 to see why there's no compression in cylinders 1 and 2. I was hoping it wasn't anything seriously expensive, and was happy to discover that it was only the head gasket had blown between 1 and 2. Woohoo!

GPZ1100 Saturday 26 July 2025 by Terry Prendergast, on Flickr

The good thing was that I found these high comp pistons lurking inside, which may have been the reason that the original gasket blew.

GPZ1100 Saturday 26 July 2025 1 by Terry Prendergast, on Flickr

I drove back to my place and ratted through my tubs of Kawasaki parts left over from my previous Kawasaki builds. I found a NOS KZ1000 copper gasket, but of course the bores on a KZ1000 are only 70mm, whereas the GPZ1100 bores are 73mm. Hmmnn, well it's easier to make holes bigger than smaller, so I drove over to the hardware store and bought a drum sander attachment for Spotty's drill. I laid the old gasket over the new gasket, and using a sharpie, traced the cylinder OD's from the blown gasket to the new copper gasket, then spent an hour or two enlarging the cylinder holes.   

The next day I finished enlarging the holes in the copper gasket, then gave it a nice thick coat of copper spray, and after cleaning both the head (that Spotty had scrubbed clean with brake cleaner and a wire brush) and the cylinder block gasket mating surface, before putting the gasket in place, then torqued the head down in three stages, 15/25/35 pounds feet. We reinstalled the cams and checked the valve timing, fitted a new cam cover gasket, and the cam cover. On Saturday we'll reinstall the carbs, exhaust, oil cooler and coils, throw some fuel into the tank, and hopefully fire it up. I'm looking forwards to getting it roadworthy and on the road legally, it'll be a fun bike.

Very nice 
How's the carbs on it ?

[Terry in Australia]

On the weekend, Spotty and I removed the head from the GPZ1100 to see why there's no compression in cylinders 1 and 2. I was hoping it wasn't anything seriously expensive, and was happy to discover that it was only the head gasket had blown between 1 and 2. Woohoo!

GPZ1100 Saturday 26 July 2025 by Terry Prendergast, on Flickr

The good thing was that I found these high comp pistons lurking inside, which may have been the reason that the original gasket blew.

GPZ1100 Saturday 26 July 2025 1 by Terry Prendergast, on Flickr

I drove back to my place and ratted through my tubs of Kawasaki parts left over from my previous Kawasaki builds. I found a NOS KZ1000 copper gasket, but of course the bores on a KZ1000 are only 70mm, whereas the GPZ1100 bores are 73mm. Hmmnn, well it's easier to make holes bigger than smaller, so I drove over to the hardware store and bought a drum sander attachment for Spotty's drill. I laid the old gasket over the new gasket, and using a sharpie, traced the cylinder OD's from the blown gasket to the new copper gasket, then spent an hour or two enlarging the cylinder holes.   

The next day I finished enlarging the holes in the copper gasket, then gave it a nice thick coat of copper spray, and after cleaning both the head (that Spotty had scrubbed clean with brake cleaner and a wire brush) and the cylinder block gasket mating surface, before putting the gasket in place, then torqued the head down in three stages, 15/25/35 pounds feet. We reinstalled the cams and checked the valve timing, fitted a new cam cover gasket, and the cam cover. On Saturday we'll reinstall the carbs, exhaust, oil cooler and coils, throw some fuel into the tank, and hopefully fire it up. I'm looking forwards to getting it roadworthy and on the road legally, it'll be a fun bike.

Very nice 
How's the carbs on it ?

Thanks Bill, the carbs appear to have been modified from stock, they were filthy of course, but after a few hours in my ultrasonic cleaners (little one for the jets etc and big one for the carb bodies) they look like new. If they don’t work I have some 33mm Mikuni smoothies in a tub, but if they’re ok I’ll use the CV’s as they have such a light throttle compared to regular slide carbs.

[grcamna2]

On the weekend, Spotty and I removed the head from the GPZ1100 to see why there's no compression in cylinders 1 and 2. I was hoping it wasn't anything seriously expensive, and was happy to discover that it was only the head gasket had blown between 1 and 2. Woohoo!

GPZ1100 Saturday 26 July 2025 by Terry Prendergast, on Flickr

The good thing was that I found these high comp pistons lurking inside, which may have been the reason that the original gasket blew.

GPZ1100 Saturday 26 July 2025 1 by Terry Prendergast, on Flickr

I drove back to my place and ratted through my tubs of Kawasaki parts left over from my previous Kawasaki builds. I found a NOS KZ1000 copper gasket, but of course the bores on a KZ1000 are only 70mm, whereas the GPZ1100 bores are 73mm. Hmmnn, well it's easier to make holes bigger than smaller, so I drove over to the hardware store and bought a drum sander attachment for Spotty's drill. I laid the old gasket over the new gasket, and using a sharpie, traced the cylinder OD's from the blown gasket to the new copper gasket, then spent an hour or two enlarging the cylinder holes.   

The next day I finished enlarging the holes in the copper gasket, then gave it a nice thick coat of copper spray, and after cleaning both the head (that Spotty had scrubbed clean with brake cleaner and a wire brush) and the cylinder block gasket mating surface, before putting the gasket in place, then torqued the head down in three stages, 15/25/35 pounds feet. We reinstalled the cams and checked the valve timing, fitted a new cam cover gasket, and the cam cover. On Saturday we'll reinstall the carbs, exhaust, oil cooler and coils, throw some fuel into the tank, and hopefully fire it up. I'm looking forwards to getting it roadworthy and on the road legally, it'll be a fun bike.

Very nice 
How's the carbs on it ?

Thanks Bill, the carbs appear to have been modified from stock, they were filthy of course, but after a few hours in my ultrasonic cleaners (little one for the jets etc and big one for the carb bodies) they look like new. If they don’t work I have some 33mm Mikuni smoothies in a tub, but if they’re ok I’ll use the CV’s as they have such a light throttle compared to regular slide carbs.

The carbs are modified of what they were originally?
I know the bike was fuel injected originally,but I don't know what you mean.

[Terry in Australia]

On the weekend, Spotty and I removed the head from the GPZ1100 to see why there's no compression in cylinders 1 and 2. I was hoping it wasn't anything seriously expensive, and was happy to discover that it was only the head gasket had blown between 1 and 2. Woohoo!

GPZ1100 Saturday 26 July 2025 by Terry Prendergast, on Flickr

The good thing was that I found these high comp pistons lurking inside, which may have been the reason that the original gasket blew.

GPZ1100 Saturday 26 July 2025 1 by Terry Prendergast, on Flickr

I drove back to my place and ratted through my tubs of Kawasaki parts left over from my previous Kawasaki builds. I found a NOS KZ1000 copper gasket, but of course the bores on a KZ1000 are only 70mm, whereas the GPZ1100 bores are 73mm. Hmmnn, well it's easier to make holes bigger than smaller, so I drove over to the hardware store and bought a drum sander attachment for Spotty's drill. I laid the old gasket over the new gasket, and using a sharpie, traced the cylinder OD's from the blown gasket to the new copper gasket, then spent an hour or two enlarging the cylinder holes.   

The next day I finished enlarging the holes in the copper gasket, then gave it a nice thick coat of copper spray, and after cleaning both the head (that Spotty had scrubbed clean with brake cleaner and a wire brush) and the cylinder block gasket mating surface, before putting the gasket in place, then torqued the head down in three stages, 15/25/35 pounds feet. We reinstalled the cams and checked the valve timing, fitted a new cam cover gasket, and the cam cover. On Saturday we'll reinstall the carbs, exhaust, oil cooler and coils, throw some fuel into the tank, and hopefully fire it up. I'm looking forwards to getting it roadworthy and on the road legally, it'll be a fun bike.

Very nice 
How's the carbs on it ?

Thanks Bill, the carbs appear to have been modified from stock, they were filthy of course, but after a few hours in my ultrasonic cleaners (little one for the jets etc and big one for the carb bodies) they look like new. If they don’t work I have some 33mm Mikuni smoothies in a tub, but if they’re ok I’ll use the CV’s as they have such a light throttle compared to regular slide carbs.

The carbs are modified of what they were originally?
I know the bike was fuel injected originally,but I don't know what you mean.

I think the CV carbs have had an aftermarket "Dynojet" jet kit installed, to allow the CV carbs to work better without their usually restrictive airbox and filter. I installed a Dynojet kit on my Suzuki GS1000S many years ago and it ran very well with a modified airbox and K&N filter.

[Alan F.]

That's a lucky break on that head gasket Terry, cheers.

I'm honestly surprised how few forum members over on the RE Owners forum have gone with bigger bore kits or cams. 750cc, 750cc high compression, 850cc, 865cc, and high compression 865cc seem to be the common ones so far.
Swapped back to street tires the other week and  my bike accelerates right up to 95mph as easily as it used to. The rear knobby tire had a larger diameter and ruined the gearing, it'd do 70-75mph but it wasn't much fun there. I'm running booster plug, DNA filter & snorkel delete, and better mufflers. I've got a Tec 2:1 that I haven't bolted on yet, maybe soon.

[Terry in Australia]

That's a lucky break on that head gasket Terry, cheers.

I'm honestly surprised how few forum members over on the RE Owners forum have gone with bigger bore kits or cams. 750cc, 750cc high compression, 850cc, 865cc, and high compression 865cc seem to be the common ones so far.
Swapped back to street tires the other week and  my bike accelerates right up to 95mph as easily as it used to. The rear knobby tire had a larger diameter and ruined the gearing, it'd do 70-75mph but it wasn't much fun there. I'm running booster plug, DNA filter & snorkel delete, and better mufflers. I've got a Tec 2:1 that I haven't bolted on yet, maybe soon.

Thanks Alan, yeah I'd almost convinced myself that I'd be better off removing the head from my 1428 engine to put on it, so I'm lucky that I didn't, because I'd have 2 good heads, and still have a blown head gasket.

I had to laugh on Wednesday, I dropped the boy's Royal Enfield off at the dealer for a service, and to have the front brake caliper looked at. I had to ride the bike around 15 miles with only the back brake because the front brake locked on only a few hundred yards from my place, and I had to wait while the caliper cooled down and eventually released it's grip on the disc before I could ride off again. It was only in the 40's and the disc was smoking...

Anyway, I arrived at the shop in one piece, and told the service manager about the problem with the front brake, and he supposedly didn't know that this was an issue with early 650's, so I just said that I won't be taking it home until it's fixed. He rang back later on Wednesday to say that the service had been done, but I might have to wait a couple of days while they sort out the front caliper. I said that was fine, it's winter, so not ideal riding weather anyway.

I remembered that you'd mentioned that there was a factory recall on certain models for brake calipers that were prone to corrosion, causing the brakes to stick on, so I checked the internet, and yep, there was an Australian recall in 2023. My son had bought the bike new from that shop, so I'm a little surprised (and slightly pissed off) that they hadn't contacted us to have it brought in for repair/replacement. If they try to charge me for the repairs to the front brake, it won't go well..

[Magpie]

Brought a new project home just before a 2 week holiday. I applied for the Collector plate available in BC today. It should re-qualify.
1969 Triumph Bonneville. I had a 1968 new but it went away as soon as I saw the !969 CB750.
Cliff.

[simon#42]

i like that , good find