Kawasaki H2 750

[Joe H]

I know I'm chiming in late here, like maybe too late, but that swing arm looks real flimsy compared to later sport bikes, the frame too.
I'm sure racers beefed those up, I would too.

Its from 1972...... Modern only if your where born before 1955... LOL

Believe it or not most race these bikes with stock swingers which are way flimsier than the yamaha Rz swinger on this!
The frame was braced but again most guys who race just think this adds unneeded weight. Of course there's the vintage rules they also must follow.
This bike will only produce around 90hp that won't overpower this set up.
My moto is if you want modern buy modern there better all the way around!
If I started this project from scratch I would have left it even more stock.
Modding is fun and neat and SUPER COOL but there's always a weak link.

And I may leave the graphing I have decided yet!

[Joe H]

Thought Id post a couple pics of the frame bracing that was done, It was copied from original DENCO specs.
There are gussets welded from the steering head to the frame. This Mod is one that a lot of guys says works well.

There were cross braces welded into the rear section just before and above the swing arm (the sideways X). And like I said the swinger is an RZ350 box section steel, the common mod for these bikes is a FZ400 swinger which is probably lighter than this unit, but seeing this one is steel its pretty strong.

And you can see the engine mounts on the front have pieces welded in place that Kawasaki added to later frames but this one didn't have them to start because it was an early frame.

There are a few out there who have successfully modded these old bikes with some really neat stuff, single sided swingers, case reeds, you name it its been done and they are fabulous. Also many are getting well over 100hp and some with 125 and 130 HP.

[Rob S.]

This is a time machine...

The year is 1973. An H2 and a Z1 are parked side-by-side. The two undisputed kings of the street...the bikes that made Kawasaki.

[madmikeracing]

Had to ad this was my very first street Bike a 1972 H-2 I bored it .080 over and 38 s some port and machining work, It had the freakiest hi speed wobble I've ever had, The bars would dip left to right at WFO and take up an entire Lane at 100 plus mph, The steering necks are way out on the frames ,may be good to look into this. Good Luck looks Good Mike

[Joe H]

Some were good others not so much! Depended on their Sake' consumption the night before..
The big key is the steering dampener and making sure the tabs on the frame are not broken and it is working properly, or on the early ones that it will tighten the stem well, even then some of them where not so good.

This one had the steering stem replaced with a new one that would except a 86' GSXR front end and the rear end is from a RZ350. It was put together by a frame builder in Milwaukee, its straight.
I am currently working out some carb tuning and ignition timing stuff, which is a big learning curve for me, I like my GS and know it well, this 2 stroke stuff is all new to me.
It needs some suspension work on the rear shock, that will be rebuilt with stiffer springs and dampening to match this winter, and it needs new tires, they are from 1996…old and hard! Its a bit squirrly with the way to soft rear shock and really hard tires.

As it sits I have had it to 87mph with no problems, although without the GSXR steering dampener Im not sure how it would handle, and the problem with High speed wobble is it happens like the blink of an eye!
Believe me I approached the higher speeds and corners with caution at first and will continue to do so until I prove its stable.
I am looking forward to new tires and a better set up rear shock.

OH and thanks for the compliments and concern , one reason I love forums... the collective knowledge. (good forums that is)

[Joe H]

I don't think I posted a finished pic yet so here it is (still a work in progress!);

[Rob S.]

About that high-speed wobble (I had a '73 Z1): braking can make it worse. If there's room, keep the gas on and slowly bleed speed.

Your bike is gorgeous. Many happy miles.

[Nessism]

Wow Joe, that bike looks SO cool. Love the lines and that mini chin fairing really blends with the look. You thread should be required reading for anyone considering making a cafe.

You done GOOD!

[steve murdoch]

Talk about polar opposites in the 2 bikes.
Your Kawi looks great.

[Joe H]

Talk about polar opposites in the 2 bikes.
Your Kawi looks great.

They are opposites! The HD has 107 S&S motor with 120 ft lbs of torque right of idle, its a blast to ride, any twist of the throttle and it LEAPS forward, it runs out of breath at around 5000 or 6000 rpm, but its still faster than the H2 by a long shot.
The H2 is a kitten under 6000 rpm feels like a big moped and then at 6000 rpm all hell breaks loose.
One you have to be careful off the line the other you have to be careful when is all wound up!

Both bike were my cousins , the H2 he never finished and I inherited it in pieces and finished it, the HD is the bike he was riding when he crashed and ended up brain damaged.
It was rebuilt and it sits unused in my uncles garage, the day the pic was taken I went there to see my uncle and he wanted me to ride the HD to make sure the clutch and trans got some lube. He starts it once a week lets it get hot and then shuts it off and rolls it forward and back so the tires don't get a flat spot..... Its a ritual he has done for years and its kinda heart breaking

And thanks for the kind words Ed! It means a lot, your work is impeccable.

[Jackman]

Joe, Awesome job on the H2 , really cool getting the family pics your cousin would be proud. Funny your Uncle looks a lot like my Uncle right down to to the cigarette in hand and the no emotion personality

[dorkburger]

What? There was another bike in the background?

I recall many many years ago paging thru a lingerie catalog that ended up at our house. I nearly flipped my lid when a model was posed on one of the best looking model year ('66, duh) Chevelles. Perhaps my then new wife should have ran away then.......

[Joe H]

Must be a generational thing with those guys like my uncle, they were the original tough guys, we could use more like them now a days!
Just get it done and don't freaking brag about it or whine about it!

I really like the picture of the Harley and the H2 I may get it framed for my work area.
I went back and looked thru the thread..
Those pics with the family were taken at our old shop which was my grandma and grandpas house, I "grew up" there, spent 45 yrs of my life there. Almost 30 of it going to work everyday at grandmas house, thats where we ran the family business from.
All those beautiful trees and the house and the shop and all the barns are all gone now…they tore it down this summer, its now an ALDI's food store…
WOW, A lot of change fast in the last year for me….

Oh and the H2 is in pieces again

[Buffalo Bill]

Yeah, I like it did you weight it?
In pieces again? Well whatever, it is too icy to ride.

[Joe H]

Yeah, I like it did you weight it?
In pieces again? Well whatever, it is too icy to ride.

Yes I weighed it, 2 bathroom scales with plywood on top of the scale to better distribute the weight, one under each wheel, 190 front, 210 rear total 400lbs.
I asked around and is seems close, I don't know if its perfectly accurate, I doubt it.

Im having the transfer ports raised a bit to increase intake duration, it should help with the flat spot and the jetting, with the blowdown numbers I have increasing intake duration it would suggest it will help. That what I have been told and the research I have done on 2 stroke porting agrees with this assessment.
Also doing some mods to the ignition to be able to play with a bigger timing curve, and I purchased new needles for the carbs on a recommendation from a someone who races these old machines and has found this needle to work well with the carbs I am using. But he never had reeds so it may or may not be a better needle for me.
We will see if this all works as planed..

I am also addressing the rear shock, needs a stiffer spring and most likely new valving. Its way to soft it sags over 4" when I get on it. And it bottoms out every time I hit a largish bump. I may have to modify the linkages