The ZX1R story

[bungbung]

Im still failing to see how the cam timing will have changed from stock

Stretchy cam chain?

[F5 Dave]

Just whenever you do that's radical like changing a whole tooth it might be nice to see if the valves then clash with the pistons ideally with some plasticine to ensure clearance is still ok if varying much from stock. Would be a fine idea to check cams in correct position.

Bloody 4 strokes.

[Skunk]

Just a quick question, Have you experimented with your ignition timing at all?

Im still failing to see how the cam timing will have changed from stock, and even stock timing should be able to handle the increase in CC.

I'd slot it both ways. It doesn't matter and it's not exactly hard!

Ignition timing has been changed but made know real difference. Block height has changed. I just want to set it correct. To do that it must be measured.

Slotting it both ways still doesn't tell me where it should be...

[Sketchy_Racer]

No but it lets you slowly figure out by trial and error which way it needs to go, and means if you cock up your calculation of which way you think it needs to go, you don't have to pull them out and re-machine them.

[CM2005]

sounds complicated... lol agree with F5dave. also, you guys know anyone that races buckets down in palmy? i'm out at ohakea, and i'd be keen to see manfield.

[Skunk]

I've slotted the cam drive so I can adjust it and set the cam and crank at the std positions. The cam drive is a degree or two further forward than normal which would be right with 1mm off the block.

CM2005 - get your arse to Welly for the meetings, or Waipawa. You did bring your bucket bits? You could get the rebuild done by Pete Sales.

[Skunk]

Well. At the Battle of the Buckets Sully60 broke his motor so a swap with mine was attempted. In the course of this swap we discovered something about my engine.
It has now been fixed, but the bike is heavier than it was. At least the crank now gets oil though. I've never taken the clutch cover off before so at some stage of the engines life someone has and didn't refit the oil feed to the crank.

Thanks to Sully60's eagle eyes () a complete meltdown has been avoided.

We'll see how it goes at the Slipway on the 29th June; It seems pretty good at the moment. A few other tweaks and it starts first kick from cold with no choke. Damn, that's better than it ever was...

[Skunk]

Still no power at the 3000+rpm range. Took the opportunity to trial several different timing settings (+15 through to -15 from standard) all of which made no difference to the 3000+ range. So I guess it must be the carbs. I'll be looking at the main jets next round.

[Skunk]

Well, richer didn't help. But my expert reckons it's too rich. Think I might listen to him now.

Just need to get some jets...

[SHELRACING]

Anyone able to help with cam timing?
I need to adjust the factory set-up. I'm not too sure on the process though.

I ran a twin for a while. Bloody quick bike. I won Taupo bucket meet on it 2 years back. But I kept dropping valves due to over revving. Gave up on the motor after it blew up for the fourth time

It had a total loss FZR system, which I still have CDI, Pickups, Rotor for the crank, custom made back plate, including the wiring . I dont know that I want to part with it. But If I find it all I could photograph it for ya if you need some references.

I found the cam timing a C@#t of a job. The valves need to be dialed in. At least it did with the Total loss system fitted. It was over my head anyways I had to get John Connor to time it for me in the end.

[AllanB]

A bit of Alridite will fix that piston.


Can anyone explain the h dropped into Gay - is it for Honda?

[Skunk]

It had a total loss FZR system, which I still have CDI, Pickups, Rotor for the crank, custom made back plate, including the wiring . I dont know that I want to part with it. But If I find it all I could photograph it for ya if you need some references.

I think it was Speedpro who was telling me about that engine. I would be very interested in any info you can come up with.
I'll be up to the Taumarunui Races October 11th and 12th. Staying at the Hilton.

I'm working on a rev limiter that cuts one cylinder too.

[koba]

I'm working on a rev limiter that cuts one cylinder too.

Its about bloody time one of you guys with the twins sorted a proper rev limiter!
It seems VERY nessecary!

[Skunk]

Hmm, yeah. Anyone know the ignition on these very well?
I'm thinking there's a waste spark... the points are triggered every rev rather than every second aren't they?...

Yes, we're designing the circuit now - how-to/can-we is done. Now we build.

I've also been looking at valve materials etc. Honda ones of that age seem to be shite. Sully60 has independently been doing the same thing.

[speedpro]

A rev limiter is not neccessary if the motor is built properly. Have a listen to the ones Gaz and Karl are riding. They have John Connor big cams as well and are out to 140-150cc.