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PostPosted: Thu May 11, 2017 4:56 pm 

Joined: Sun Jan 15, 2017 7:00 am
Posts: 94
Location: NORAD Colorado
Hi guys/gals-

Got my engine out and cleaned up out of my H1B. Gonna build a hybrid. Was a barn find, guessing it sat around before i got it for a good 10 years. when I got it, I cleaned carbs, oil down cylinders, fresh fuel, cleaned up points, repaired minor wires and after about 25 kicks or so, fired right up. ran good for as long as it had been sitting, ran it for bout 20 min. that was bout 5 years ago. engine has been stored inside since and is not locked up. other than the normal gaskets/seals to replace, should I just tear into the entire engine and do everything? (split cases, change crank bearings, internal seals, etc?) What are your opinions as to what i should do to get it ready for a new chassis?

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Thanks!


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PostPosted: Thu May 11, 2017 6:24 pm 

Joined: Sat Oct 04, 2014 3:45 am
Posts: 796
Location: Cen Tex
If you are looking for long term reliability, then a complete motor rebuild may be in your future. Once you get the top end off, you can mic the bores and see if there are in spec, maybe just hone and rering.
However, if your motor has never been apart, it is quite possible that your crank seals are dried out, and if so, leaking and will cause the motor to run lean and eventually fail [guess how I know?!!]

If you have the money to invest, go through the motor.

BTW - would is your "Hybrid" plan?

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H2B..... H1E..... Z1B ..... RD350...... X6 Hustler..... TS250.... CB750 ..... CB550...... and a Bomber!!


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PostPosted: Thu May 11, 2017 10:32 pm 
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Joined: Fri Jun 10, 2011 11:04 am
Posts: 3490
Location: Capitol of Ca, USA
I always thought it'd be nice to shoehorn a Triple motor into either a 550 or 750 Zephyr chassis - triple disc brakes, better suspension, yet still retain a Kawasaki "standard" look.
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PostPosted: Fri May 12, 2017 10:56 am 

Joined: Sun Jan 15, 2017 7:00 am
Posts: 94
Location: NORAD Colorado
Stev-o wrote:
If you are looking for long term reliability, then a complete motor rebuild may be in your future. Once you get the top end off, you can mic the bores and see if there are in spec, maybe just hone and rering.
However, if your motor has never been apart, it is quite possible that your crank seals are dried out, and if so, leaking and will cause the motor to run lean and eventually fail [guess how I know?!!]

If you have the money to invest, go through the motor.

BTW - would is your "Hybrid" plan?


Not sure yet, on the hunt now for the right donor/Rolling chassis. Maybe a gsx? Have a possible lead on a ninja 250 chassis.


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PostPosted: Thu Mar 01, 2018 9:01 pm 

Joined: Sun Jan 15, 2017 7:00 am
Posts: 94
Location: NORAD Colorado
Sorry it's been a bit guys....
Got my doner bike (85' zx600), looking at it and my engine I want to use, what do you think? Can it work?
Other than losing the direct oil injection system, anyone ever done or see an issue with reversing the cyclnders as an option? Just looking for ideas/opions.


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PostPosted: Thu Mar 01, 2018 9:58 pm 
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Joined: Thu Sep 29, 2016 4:32 am
Posts: 615
Location: Indianapolis, IN
Reversing the cylinders puts the piston thrust side on the exhaust side, the hottest part of the cylinder, and will lead to piston seizures. Very few 2 strokes have the exhaust port on the thrust side, and are usually trouble when they do. Witness the Honda MVX250, an early '80s 250 triple laid out in a vee configuration, the center cylinder had the exhaust port on the rear of that cylinder, and it also seized that cylinder often. One standout from that idea is a Parilla kart engine, they get away with it for some reason, I never took the time to study how they do it.

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1974 Kawasaki H2B 750, 1981 Yamaha XV750 Cafe, 1986 Kawasaki KDX200, 2003 Honda XR100, 2004 SDG140. 2006 Ninja 500R Turbo intercooled fuel injected.


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PostPosted: Fri Mar 02, 2018 4:19 am 
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Joined: Thu Jun 09, 2011 3:06 am
Posts: 4364
Location: PARIS FRANCE
+1 work with water cooled engine usualy (Suzuki RG 500 Gamma for example, Honda MVX don't count it's an Honda) but not on aircooled engine with the exception of the gorgeous Guazzoni Matta 49cc :mrgreen:


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PostPosted: Fri Mar 02, 2018 4:51 pm 
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Joined: Tue Jun 07, 2011 6:37 am
Posts: 10460
Location: Rio Rancho, New Mexico
It's been done before. It is mostly only for the "I could, so I did" mind think. A lot of work, with no advantage. I believe the wrist pins are off set for face loading, so they would need to be reversed also.

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PostPosted: Sat Mar 03, 2018 2:49 pm 

Joined: Thu Jun 09, 2011 11:25 am
Posts: 3137
John is right about the Sipes angle (piston pin offset from centered), needs to be on the other side of the piston to make the rod angle work and not induce more piston to cylinder thrust.

As far as all the rest, not so fast. I have done 6 H1, and 2 H2 air cooled engines with cylinders mounted exactly as in the picture above, with stock crankshaft rotation. I did them when the original dirt car class TQ was created. Those engines did not have any piston issues caused by heat, seizure, nor thrust, they had nice pistons with the right Sipes angle done. As far as heat, there was also NO PROBLEM, and the crank spinning "the wrong direction" was not an issue.

In fact, there have been a few single crankshaft reversed cylinder racing engines built over the years, including Yamaha YZR 500 inline 4, two center cylinders facing forward, two outer ones facing reversed (Roberts rode one to two world championships and an AMA title), Honda NSR inline 3 and 4 cylinder engines, all cylinders facing to the rear, their 3 cylinder V engine, two front, one rear, and others, NO PROBLEMS.

Then, when the FIM had an active sidecar racing program, the engine of choice was the older TZ700/750 4 cylinder, air cooled, with different air cooled Yamaha, or Honda dirt bike cylinders, reversed in the cases.

Think about it, reversed cylinders on an H engine run the exhaust temps off the barrels far better than having that heat travel through the cooling fins, carbs stay cooler, and if one builds a simple aluminum sheet "ram air system", as we did for the TQ's, even better.

Then, we have engines like the RG and RZ 500, with same rotation cranks, that also used front and rear facing cylinders, in square and V configurations. And, later, lets not forget all the V4, V6, V8, V10 and V12 four stroke single crank engines, one side rotates "conventional", the other, "reversed". NONE of them are "apples to oranges".

As far as stock oiling goes, why not the stock system, with the delivery to the cases? There is room for it, and, with stock hard lines between the pump fittings and check valves. For other connections, a flexible plastic tubing, set in place of the hard plastic delivery lines, moves the delivery any place you like, just like the carb lines on H2 with 4 outlet oil pump systems use, no problems.

I don't have those engines in my possession, but I do know that all are still in existence, sitting away from the world, and all still run as built. And, NO, I don't have any pictures of them, I didn't take pictures of just about anything, except women in the pits.

Simple as that.


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PostPosted: Sun Mar 04, 2018 5:43 pm 
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Joined: Thu Sep 29, 2016 4:32 am
Posts: 615
Location: Indianapolis, IN
Regardless of all the given examples, there is no doubt that the thrust side of the piston and cylinder runs hotter than the non thrust side. Air cooled engines have more uneven head and cylinder temps than water cooled engines. If your engine was borderline to the point of seizure before you reversed the cylinders, and you changed nothing else to deal with the problem, you can then get a seizure. Apples to Apples.

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1974 Kawasaki H2B 750, 1981 Yamaha XV750 Cafe, 1986 Kawasaki KDX200, 2003 Honda XR100, 2004 SDG140. 2006 Ninja 500R Turbo intercooled fuel injected.


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