Dual Plug cylinder head for GPZ 750

I seen Rob Muzzy use a dual plug cylinder head he built for 1983 AMA GPZ 750 Wayne Rainey s rode, and I had a spare cylinder head for an 83 gpz 750. So I went for it and thought I would post a thread with pic. I used an old magazine article for ref. I won't bore you with details about doing the milling and michining. I'm pretty excited to try it out next spring ,but I want to Dyno my bike with the stock head first to get some HP numbers then switch out to dual plug head and get HP numbers.I'm using Dyna 2000 ignition and four 6volt 1.5 ohm dual output ciols from dyna .Dynatec was very helpful when asking about conversion. :woohoo:

Looking forward to seeing your results!

I dont want to forget and say I'll be doing a valve job and cc the head to make sure they r within a tolerance I can except . I'm also going to paint it!

RTGPZ wrote: I won't bore you with details

Please do!

RTGPZ wrote: I seen Rob Muzzy use a dual plug cylinder head he built for 1983 AMA GPZ 750 Wayne Rainey s rode, and I had a spare cylinder head for an 83 gpz 750. So I went for it and thought I would post a thread with pic. I used an old magazine article for ref. I won't bore you with details about doing the milling and michining. I'm pretty excited to try it out next spring ,but I want to Dyno my bike with the stock head first to get some HP numbers then switch out to dual plug head and get HP numbers.I'm using Dyna 2000 ignition and four 6volt 1.5 ohm dual output ciols from dyna .Dynatec was very helpful when asking about conversion. :woohoo:

6v coils?

It s pretty straight forward I threaded 6061 alum. and welded the plugs in and used a duburring tool to take excess weld off in bowl area, then turned over and used 1" end mill to clear away fins . Turned head back over to drill spark plug hole in location I had seen in pic , new spark plugs are 10mm x 1.00 3/4 reach. I then went back to top side to achieve proper hight for spark plug ,but I have to use a spacer under plug . By the way so did muzzy. I did a lil blending around valve seats and carb boots to improve flow . I probably left something out but I'll be responding to your post if needed

You can hook them in series to accomplish 12v and also adds up to 3 ohms

Ah,now it makes sense!

Does anyone know of someone that has made a dual plug cylinder head for a kz750 , I've looked and couldn't find any info on kzr for a750cc. I know they make them for bigger cc.

Can't say I've ever seen a dual plug head on a 750. Bet you have to pull a little timing out it to be where you want. Look on KZZone's website for greg copes tuning tips, I believe he talks about it.

Les

why not just find one of them multiple spark discharge units and put it on there?

That looks like a very clean mod. I hope it can prove out on the Dyno for ya. Just keep in mind the blending, CC-ing, fresh valve job and such compared to your current head may give a few ponies.
Whats the rated secondary output on the 6V coils? Over 35KV? If not a set of 12v coils, 1 per plug or dual fire may very well have more spark energy.