Dumb idea. I'm doing it anyway.

[teazer]

Much as a i love a good project, if an FZR400 makes 50 hp stock and fits and runs and a tuned RD can be egged on to make more or less the same power with a lot of time expense and heart ache, why not just run the FZR as an FZR or do you just have the chassis?

Build a 4-6 or tune the 400?  We have an FZR400 in the garage sitting beside my RZ350 and my preference is the RZ because I bought it back in the early nineties and still have it, but the fizzer is a great bike.

I'd like to fit an FZ600R tank and MotoGp M1 style seat or even keep a stock tank cover and fit a better looking seat and run it like that.  Riding positions are very different though and the slight forward lean on an FZR is not as comfortable for me as the RZ.

Or keep the RD motor and put it into a frame like Mark's?  Light and simple or build a TZ twin shock replica.  It's been done to death but they still look great and work well enough.   Just a thought though.  Fit FZR400 forks they are so much lighter than the RD and can be upgraded cheaply. I even have a spare set that supposedly were built by race-tech that bought for a project that was cancelled.

[elliottles1]

+1 on chain alignment, i actually offset the whole engine by about 1/2" on mine which made it much easier than going down the spacer route, and a steel straight edge from sprocket to sprocket to align parallel.

Teazer, my take on the FZRversusRD engine thing is this, they always get compared to the FZR engine, whereas to compare the FZR chassis to the RD chassis is a better comparison, the FZR SOOOO out performs the rd in all respects and mine also came out a whopping 25kg lighter than an LC from which the engine was derived, it was the RD that i always wanted, not an FZR that i didnt.

dont know why i sold it now!

les.

[DaytonaCafe]

Teazer, I did say it was a dumb idea but I'm doing anyway!    Anyway, I have an FZR400 with the 600 motor swap already in the stable and I certainly love it. Also have the somewhat built RD400F. So, I wanted to add another 2 smoker because they're more fun than a bathtub full of Otters when running properly and that sound! It will likely take a few years with my meager earning to complete this but my buddy has an extra FZR400 frame he said he'd part with & he's rather excited to help make this crazy bike a reality.

Mark, 100% with you on sprocket alignment. We did the whole CBR F4i rear wheel swap on the FZR400/600 & had to deal with that issue & I understand this one is even further off alignment so, my buddy is going to mock it all up with the motor out of his RZ350 since the project motor will be out being built.

[DaytonaCafe]

Seriously? I had a set of 400 DG's in my hands years ago that I had to part with to pay bills. They needed more mill work than these but were a very tiny fraction of this pricing! Am I gonna have to boot this kind of dough into Sunburst heads AND pay on top of that for them to be properly worked?

LONGSHOT: Anyone have a set they'd part with for a few fingers shy of an arm & a leg? I know these have become expensive but SHEEESH! I'm a reasonable man, I think. 

[m in sc]

if/when they do the webco heads again, better head, same price. or get a set of stock ones cut, they actually work better than DGS when correctly done.  .02

[DaytonaCafe]

Now the tool bag I am supposed to be picking the engine up from isn't responding. What the heck is wrong with people these days? He advertised, I said I'd buy and when I'd pick them up, he agreed, & now...radio silence. This project is clearly going to take even longer than imagined having to deal with these types of folks. Anyone with a lead on a workable engine, let me know! Would clearly prefer an LC/RZ but I'm fairly certain those are way outta my price range. Quite frankly, any 350 or 400 would be fine I think. I'll try to be reserved but I suck at it. 🤣

[Clem710]

I've got a whole 74? not 75 350 I could let go, rusted and locked up but dont really need it and its 95% there, mostly bought it for spares since theyre getting expensive and I'll need em eventually.

Have not taken the heads off yet. Semi near Pittsburgh Pa but over in OH, PM in case I dont see this thread again.

[DaytonaCafe]

PM sent, sir!

[DaytonaCafe]

Chalk up yet another stalled project for me! Life just has a way of chucking curve balls at me & my extracurricular activities get pushed aside. Nevertheless, there definitely isn't a time clock on this build & my buddy has all of the FZR400 parts that'll be used. I'm TRYING to get time to pick up the RD350 but family emergency with my daughter took the wind out of my sails for a bit until that was resolved (praise God) & now staffing at both of my jobs is a problem (apparently the younger generation is much less interested in being a public servant) so we're all having to work overtime.  Anyway, VERY much hoping to start adding some pics to this idea/thread to jumpstart the actual build. I'll see if I can cajole my buddy to send some pics of fzr frame with his engine mocked up in it.