I've got me work cut out for me on this one.

My daughter and I took a ride up the Jersey turnpike last Saturday all the way to the very end. We left around 4:30AM and arrived in the pouring rain about 8-8:30. Found the guys house and bought a running(although barely) 1975 H1. Of course the initial plan is to buy, restore and sell but we'll see how it turns out. I'm not even sure at this point if I want to keep it stock or do a little porting to it and exchange the stock pipes for one of the sets of chambers that I just happen to have hanging in the garage. I ported one for a guy last year to 90HP specs and it turned out to be a real beast. He ended up selling it because it scared him too badly but I enjoyed riding it the one time I took it out. The two H1's that I have are no longer running as I've taken parts off to rebuild others that I've sold in the past couple of months but this one I'll want to keep running if I decide to keep it.

The guy wanted to start it but I stopped him as we had to lay it in my Expedition. We removed and drained the tank along with the side covers since although they need to be painted, they are in very good condition with no dents or rust in the tank. He also had already bought new reproduction shocks, carb tops and a few other parts worth a few hundred dollars making the deal more attractive. After we got back home, I spent some time finding and buying parts needed for the restore...centerstand, seat cover, various bolts, kicker etc. A ton of stuff is on it's way to my house.

Now the downside....a few weeks ago when I took the turbo out of my basement "shop" I had to take my 74 H2 out of the garage to make room for the turbo. I took the H2 into the basement to begin the final assembly on one very highly modified H2. I haven't got very far since then, more honestly, haven't even started other then doing some clean up work of the entire area before I begin to replace the tranny/shaft seals and assemble the engine then the bike.

So, now I'm in a bit of a quandary.....I've got my new parts for my 75 H2 to be installed, I have the entire 74 H2 to assemble, and now I have the H1 to restore! The H1 is still laying in the back of my truck and I need to sort out my game plan to accomplish all three tasks.

I think I may have put myself into a box with only one open side. I'll probably put my parts on the 75 H2 first since I searched for them for so long, then go ahead and finish the 74 H2 since I'll be stuck for space until it's done. I probably acted a bit prematurely buying the H1 and all the parts but I know at least some of you guys will understand......

jeff

 

90 hp out of a 500? didnt my gt550 only have about 47 new? wow very impressive.

i would love to feel the power band of an H2 with some serious work done to it.

 

Can I suggest putting the H1 in the box and sending it to the UK for "Safe" keeping (I tried this with Schooter - but it didn't work).

Failing that, how about putting it ack on the road as it is, but in original colours, keeping the drops (Clubmans).

I can't believe that you are spoilt for choice with all these 2 strokes around!

 

Make up a list of "what I wanna do" and "what I need to do", make several copies and put them in key locations in the house: bathroom, fridge, TV, shop wall, computer, etc.
Kinda like weight watchers for bike builders. May or may not work, but seeing constant reminders may just trigger the "need to" response.
Just sayin'.

 

Thats really a good idea Max but truth be told, this is Springtime and I own a home so my "need to do" list far outstrips my "want to do list" with all the outside chores that come with a house....so if I started doing what I need to do, I amy NEVER get to the "want to do" list<LOL>!!

Markie...I don't know why schooter didn't go for it.....but if you're willing to flip me enough cash, I'll gladly send it to my home office's (Atkins) country for safekeeping, in fact you can keep it!

Schooter....yes, the #'s are really only guesses as Dennis (Denco) didn't have a very good dyno back in the day. The #'s are also measured at the crank....take a peek below. Unfotunately, two stroke technology hasn't kept pace with four stroke or we would now have 250hp bikes weighing in at 250lbs. There is a company in AU doing some great work but not many others. For most, riding a stock H2 today, that they rode in the 70's is a disappointment. The mind remembers blinding speed, uncontrollable wheelies....but reality is far short of that. My Vstrom which supposedly will do high 11's would kill my H2's. I'm hoping when I complete my 74 that will no longer be the case but stock, a GT550 claimed 50HP (all at the crank), an H1-claimed 60 and a H2 claimed 74hp. The later years GT550 dropped its HP rating to something like the 47 that you listed and the H1 became the KH500 and the HP dropped to 52, claimed mostly as the result of intake strangulation for EPA. When I ported that guys H1 he had told me how much experience he had on H1's and H2's so I asked him how much punch he wanted...he responded that he wanted as much as he could get with stock carbs yet he wanted it to last...so I built him a beast. Very first time he rode it I could hear him ride around the corner and bring the revs up after he was out if sight....then I heard him crack it open and almost immediately was silience...I thought he wrecked it or flipped over. A couple minutes later he came putt putting up the street and as he pulled back into his driveway, he was white as a ghost with a very forced smile on his face. He had bit the beast and the beast had bit back.....there was no mistaking that look. I took it out next and was pretty gentle with HIS bike but it made really nice power over 4500 and hit hard at 6 grand. I didn't wind it up since it was newly built but I was happy with my work.

Denco Porting Specs
(Complete)

Denco Porting Specifications-all measurements in millimeters
Column #1 Horsepower
Column #2 Exhaust
Column #3ht. to top X port width Booster
Column #4ht. to top X port width Transfer
Column #5ht. to top Intake
Column #6ht. to top X port width Piston Skirt
Column #7Amount to Remove
H2 149 31.0 X 48.0 49.6 X 25.0 49.6/51.7 97.9 X Stock 4.8
H2 141 31.5 X 49.0 49.6 X 24.0 50.9 Stock 6.1
H2 130 (Production Road Race) 32.2 X 49.0 49.9 X 24.0 50.9 Stock 5.22
H2 120 (King Cobra) 32.6 X 48.0 49.9 X 23.0 50.9 Stock 5.22
H2 120 32.6 X 65% of bore 49.3 X 23.0 50.9 Stock 5.22
H2 100 33.6 X 65% of bore 50.9 X 20.0 Stock Stock 4.00
H2 Ultra Stock 66.1 X 36.8
X 43.0 51.7 51.7 X Stock 95.9 6.00

H1 90 31.5 X 70% 47.0 47.9 Stock 2.25H1 80 32.0 X 70% 47.0 47.9 Stock 2.25
H1 75 (Road Race) 33.4 X Stock Stock Stock Stock 1.80
H1 70 33.8 X Stock Stock Stock Stock 2.00

S3 72 28.0 X 38.75 42.1 43.0 Stock 3.80
S3 66 (Road Race) 28.3 X 38.75 42.1 42.8 Stock 3.60
S3 62 29.5 X Stock Stock Stock Stock 2.1

S2 60 28.3 X 65% 42.1 42.8 Stock 5.4


- All intake and exhaust cut 70mm radius.
- 100HP and above must have heads milled about 0.020” and work your way up 0.010” at a time to attain 155 psi. This is required to compensate for raising exhaust port.
- Run only 120-130 psi for road racing.
- All Denco heads are of the dual squish design.
- Outside air temp where you are riding can have an effect. Where it is cold you can get by with higher compression. If it is hot you want to keep compression low. You may want to have two sets of heads.
- Higher HP versions used larger carbs, ie, 149HP version used 38mm carbs.

 

Jeff, I have to disagree about 2 stroke technology. I know about the AU company you're talking about, they invented direct injected 2 strokes, and the dodge neon was going to have a direct injected engine, but they were delayed and then just threw in the 4 banger that is in it now. Ski doo uses direct injection now on their sleds, and it puts all of our 2 strokes to shame, we get around 8mpg on our sleds, while the ski doo can get 20, use about 25% of the oil we do, all the while producing more hp, with a cleaner emission than a 4 stroke.

i also hear of a wet sump 2 stroke that doesnt need oil.. but i'm not 100% sure if that's correct

 

You are absolutely right about sled and ski technology....I should have qualified my statement. I have spent many hours studying both the sleds and skis trying to figure out how to "import" a supercharged two stroke cylinder block onto one of my transmissions but lacking the fabrication facilities or the $$ to pay someone else a kings ransom, have been unable to solve the "how can I do it" part.

Here's a couple of cool links;

http://webcache.googleusercontent.com/s ... clnk&gl=us

http://www.twostrokeshop.com/TSS1100GP.htm

http://webcache.googleusercontent.com/s ... clnk&gl=us

The best I've been able to come up with is reed valves for my 74 H2. I bought one set of reed valves built to be a bolt-on addition but require some relief work on the face of the cylinder intakes. If I decide to use them I'll do that work when I port the cylinders. I also recently bought a set of cylinders with 3/4 of the intake side of the fins removed and huge intakes cut into each of the cylinders so 40mm carbs can be installed. I heard that Larry at Redline will fab a set of adapters for me but I haven't chatted with him yet.

So yes, there have been several breakthroughs, but no one has applied them to a street going two stroke other then the smaller Aprilas and other specialized bikes. I'd pay a mortgage for a big, 750cc of more road going two stroke. Supposedly, a guy on another forum has ordered a 500cc engine from the company in AU but they've run into several design issues and he's still waiting.

If you have information that would help me, I'd sure appreciate any links/info that you may have heard of or know about.

jeff

 

Hey Jeff
You may know of this site already, but just in case you don't here's a link to "Kawasaki Triples Canada"
http://triplescanada.proboards.com/index.cgi
There may or may not be some info or parts for you, figured it wouldn't hurt to point you at them.

 

I've always thought about taking a arctic cat thunder cat (1000 cc triple) which stock is around 170 hp, mating it to a 6 speed transmission, like a harley, and seeing what that would do, but of course i have no funds to do anything like that right now and gearing would be off. or simply using the snowmobile clutch system and having to use a jack shaft, then you could really run it hard, it would keep it in the power band at all times.. and there are insane upgrades for the motor.... 200 bhp would not be hard

 

oh, and I doubt we will see 2 strokes in motorcycles at all.. even snowmobiles are going to 4 strokes, this year arctic cat came out with hteir new chassis, and you can only get the 800 twin 2 stroke in the new frame, no 600 or 1000... kind of upsetting. yamaha is all 4 stroke, ski doo's 4 strokes are gaining momentum, polaris is still pretty 2 stroke heavy. 4 strokes in dirt bikes are far superior than 2 strokes... it's sad.