FZR1000 Conversion

Does anyone know if the crank, jugs, & cylinder head from an FZR1000 will fit a Maxim X lower case? I've seen a few around and a 1000cc maxim x would be kind of cool.

 

I would think that it would be easier to fit the whole motor in the Maxim X frame, with some mods of course.
The Max lower case is made for 700/750 cc's, don't think it would hold up to 1000cc's for long.

 

I think they're totally different. Different angles on the cylinders. You'd probably want to swap the whole thing.

 

They are completely different engine designs so I doubt it would fit even with EXTREME modifications. Even the FZ750 uses a different bottom end than the maxim x so that wouldn't fit either. The top end of the FZ is angled way more than the maxim x to allow for the downdraft carbs. Not to mention, I don't think the maxim x would handle well enough for much more power than it already has.
My advice...Just go get an FZR1000!

 

The Maxim-X uses the same top end as the FZR750, valve train and all. The Maxim-X bottom end only differs from the FZR750 in the fiinal drive arrangement, and cylinder base angle.

The bottom end of the FZR750 was not changed when the displacement was bumped to 1000cc, but there are differences in the later FZR1000 engines (cooling passages, I think) that are supposed to make it impossible to fit it to the FZR750 lower end. An early FZR1000 top end should swap over to the X bottom case. I have never done the swap myself, so there may be other fitment isues to deal with.

The cylinder angle difference is at the case, and serves to solve a packaging issue so the Maxim-X could still look like a cruiser and have good intake flow from the airbox.

 

Yeah, thats true they do share the same top end, so I guess it would work. However the maxim x uses different pistons than the FZR because they had to shorten the stroke in order to be less than 700cc required to avoid the ITC tariff. So you'd have to use the pistons from the FZR as well.
You would have to use the intake manifolds and carbs from the X though...and would probably have to rejet as well.

 

My wording wasn't quite accurate there so here's an excerpt from a 1985 issue of Cycle Magazine to clarify:

Sliding the Maxim under the ITC tariff wall was a matter of clipping the FZ's 51.6mm stroke down to 48.0mm, one of the shortest stroke dimensions in all of motorcycling. With the same top-to-bottom cylinder-block height as the FZ and a shorter stroke, new pistons had to be made to bring the Maxim's compression ratio back up to FZ-spec 11:1. These pistons are longer from wristpin to crown than the FZ's, and we suspect the weight of their additional material is partially responsible for the Maxim's lower redline - 10,000 compared to the FZ's 11,000 rpm.

 

Assuming that he's going to be using a whole FZR engine in the swap he will also have access to the FZR's con rods and crank. I generally open up the bottom end of any engine when doing any major top end work, just to check things out. At that point changing the entire rotating assembly (including bearing shells) is not much more work.

Or.....get a Canadian Maxim-X

 

You'd have some major differences to contend with, as most others have pointed out.

Doing a big bore on an '86 or '87 FZX700 using an '87/'88 FZR1000 for a donor would be a more doable conversion. Keep in mind that you would also have to consider updating the remaining systems like brakes,wheels,tires,suspension,carbs, etc. to be on par with the added power.

As far as the Maxim X goes, for the most practical increase in displacement, you could upgrade to the 750cc crank, rods and pistons from a Canadian model. Or you could do what I did and import a whole bike.

Tony

 

I would've thought that bumping the displacement from 700/750 to 1000 would necessitate a different crank at least. Counterweights?

 

I'm Canadian so I have a Canadian Edition 750cc bike. Rod is thrown so I have to do a complete rebuild of the engine top to bottom anyway. Plan was to drop an FZR1000 crank into my XJ750X case, use the pistons, jugs and head from the FZR1000 and voila. There seem to be a lot of FZR1000 engines floating around at the moment so seems like a possible build. I would not want to swap a complete motor in as I wouldn't want to loose the shaft drive.

 

Linker,

I'm not trying to nix your idea, ('cause I'm a firm believer that you can never have too much power) but there are substantial design differences.

The crank may work with extra clearancing. However the coolant passages in the jugs and the intake ports in the heads are way different. That would pose a major problem adapting them to an X type layout.

Tony

 

Yep that's more of a problem then I'd want to get into. Figured since it was a Yamaha it all might bolt together.

 

Oh no, quite the opposite. And you can't just go swapping cranks without getting the correct bearing shells for your crank/crankcase combination. MamaYama ain't havin' none o' that.

Here's the rub: Yamaha color-coded the bearing shells and has an equation you apply to determine whether you need a "yellow" shell or a "brown" shell or god forbid, a "green" one to match your crank and case. And the equation uses the letter codes found on the crankcase and crank journals.

What they WON'T tell you is what the actual numbers behind those letters and colors are.

The problem with Yamaha and their apparent "parts room engineering" is that it often actually isn't. Quite often things that appear to be the same are actually quite different, although their appearance often belies their true engineering differences.