1971 Kawasaki H1

I tidied up some wiring and stuff, then I went to ride this beast for the first time on Friday, started it, warmed it up, began putting my gear on... and smelled gas.  The center carb is leaking, and of course it's the most difficult to access, so I'll have to get into that this weekend if I have time.

Ugh... so close. 

In reply to Ian F :

It is painfully close- with almost any other bike I'd just go for it, but this one has no killswitch, no throttle return cable, and brakes that are questionable by design, so I want to make sure everything is pretty good before I trust my life to it.

Totally get it.  When you do go for the first ride, try to get Sara to take some video so I can show it to my mother. Thanks.

Carbs weaseled out without removing much:  

Looks like past me set the floats a little wrong- carbs were leaking out of the vents because they could overfill.  I think it's all OK now that I reset them:  

Put it back together, fired it up, and things seemed good... except for the stuck clutch.  I can see the plates separating through the dipstick hole, so I figured I'd just ride it up and down the road to free them up.  So I strapped a gopro harness intended for dogs to my chest and did that:  

It went OK but the clutch didn't free up.  I didn't romp on it but can tell that it's going to be scary when at full power with the nearly non existent engine braking, and I really hope the brakes bed in and work a little better than they do now since the rear is acceptable but the front is "oh poop we gonna die."   The oil pump has started working on at least one cylinder so I'm hoping with more run time it gets its' act together- I can keep running premix until then.

So, after checking everything over thoroughly (the only casualty was that the tach cable hadn't been fully screwed in and fell out) I did it again... and it died at the bottom of the hill:  

Quick diagnosis revealed a lack of spark.  After getting my workout for the day by pushing it up the hill in the heat and humidity, I narrowed it down to the aftermarket CDI box- which I confirmed by turning the ignition back on and hearing crackling followed by a little smoke coming from the box.  This may very well have been the source of the battery disaster the first time I ran the bike as well- time to contact the manufacturer:  

I love the sound of a two stroke triple! Good work.

That video makes this thing look positively antique-in a good way.

I came up on RD/RZs, and remember the two stroke howl getting in my head. I always wanted to ride a Widowmaker. Carry on, good man.

Awesome! I sent the video to my mother.

BTW, remember the old high back seat? She found what looks like another part for it:

In reply to Ian F :

I think I need to build a trike or something to be worthy of that!

¯\_(ツ)_/¯ said:down to the aftermarket CDI box- which I confirmed by turning the ignition back on and hearing crackling followed by a little smoke coming from the box.  This may very well have been the source of the battery disaster the first time I ran the bike as well- time to contact the manufacturer:  

Just a word of caution...if that yellow appearing residue is from a typical ABC fire extinguisher you probably will want to clean it up soon.  Most dry chemical fire extinguisher powders are extremely corrosive, especially to electrical components.

In reply to HundredDollarCar :

Thanks for that!  I cleaned it off of the stuff I could reach but you're correct that there's still powder under the CDI box in that shot- since I've removed and shipped the box I'll make sure I clean it up.

¯\_(ツ)_/¯ said:

In reply to Ian F :

I think I need to build a trike or something to be worthy of that!

Nah... think about it... that seat... you and Sara on the H1 cruising around Bucks County... reliving the 70's... 

Lakeserv sent me a new box and informed me that my old one had failed in "a somewhat spectacular way."  Installed that, fired it up, the clutch unstuck itself, and I went for a ride:  

OK.  So.  Let's break this down into categories.

The Good:
-Seems to run very well when cold or warm
-Starts consistently
-Everything works to some degree
-Engine itself seems to be pretty healthy
-Oil injection has started working again
-Bike is just as terrifying as I imagined and I haven't even tried to go fast yet

The Bad:
-Begins to get very boggy as it gets hot, won't idle consistently when hot
-All of the cables to the carbs (throttle and start) seem to "self adjust" a whole lot and move around in their sleeves, especially at the 3 into 1 junctions.  Not sure if I just bought a E36 M3 product or if they need to break in or something

The somebody who has ridden these back in the day please tell me if this is normal or something to fix:
-Front brake is incredibly terrible, rear is actually pretty decent
-Wheels have noticeable runout
-Clanky sounds from the right side of the engine case at idle

Overall I'm pretty happy but will probably wait to mess with it much until after New England Forest Rally, need to focus on that for now.  Please weigh in on the bogging and adjustment issues (everything is set per the manual, with the exception of the idle which I have to chase constantly when hot) if you know stuff about these or other ancient 2-strokes.

I rode the bike again to see if the bogging when hot thing was repeatable- it was, especially when cruising at constant throttle.  Is that just how old 2 strokes are, maybe?  Seems like it runs out of fuel until you let the bowls refill.

I also should have brought the GoPro this time, because I decided to find out what happens if you really give it the beans; so I rolled on to full throttle at about 4k rpm in 2nd gear... and waited... and waited a little more... and then somewhere in the neighborhood of 6k rpm the bike becAME A MISSILE MADE OF BLUE SMOKE AND NOISEANDJESUSGODIMGONNAFLYOFFTHEBACKITSTIMETOSHIFTTO3RD*click*andITSRIGHTBACKINTHEPOWERBANDGODAAAAAAAHHHHHHHHHHHH.

Holy berkeley, this must be what everyone was talking about!  Getting it slowed down is equally exciting given the brake situation, and although the turn-in is sort of OK the wobbly nature of the thing makes any cornering pretty disconcerting.

Unfortunately it's only good for one pull like that before the bogginess takes over and you have to let it rest for a bit.  But wow, this thing is scarier at 60mph than most bikes are in the triple digit range.

Check to see if the brake shoes are glazed, and if the brake cable is moving easily and is lubricated.  Also check the external linkage on the side of the brake assembly, it can be tricky to get adjusted so both shoes contact the drum correctly.  My 1968 W2SS has the same front brake as the H1, and while it was no great shakes compared to a modern disk brake iit worked reasonably well.

In reply to stuart in mn :

The shoes and cable are new, but the linkage adjustment might be the culprit- it takes a lot of lever travel and force to get things to really start biting so it would make sense that it doesn't work well if a lot of that action is only getting one shoe to move.

My roommate had an H1 and I don't recall it having an issue with "bogginess."  I think I remember you saying you are running pre-mix and now the oil injection has begun working.  Could this be an issue with a bit of oil mix richness?  Perhaps intermittent mix richness with the plugs burning off the excess in between? 

¯\_(ツ)_/¯ said:

And some slightly lower bars with new grips:  

Love the Oury waffle grips.  Nice touch!

Good job putting the bike back together and sorting everything out.

Back when this was a "Yazawahzi Ape Fifty" or a wingdingdingding. My friend was a local legend on 2 wheels and one of these hospitalized him. 2 strokes are wicked.

In reply to ¯\_(ツ)_/¯ :

My mother enjoyed the video and chuckled at the 7/13 post with the comment, "you're a nice young man, please don't kill yourself."  

The "scary at speed" comment sounds similar to driving a Spitfire with the top down. You're so low and it's so loud and there's so much rattling and wondering if parts are falling off, you get plenty of excitement while often under the speed limit. 

Is the front brake lever stock? I wonder if you don't have some sort of leverage issue. Two strokes coming on the pipe is my favorite internal combustion thing in the world. It's the reason I love laggy turbos. 

My 74 Hilux once had a bogginess problem on the highway. Felt like it ran out of gas but every time I pulled over the sight glass showed plenty of fuel in the carb. With that there was some E36 M3 stuck in the carb that caused my fuel pump to have a flow rate that allowed any sort of around time driving, but would drain the bowl at sustained highway speeds. These are obviously gravity fed but how are the lines going from the tank to the carbs? And how did the tank look? Could something have broken off and caused a partial clog for letting fuel through the petcock?

In reply to mazdeuce - Seth :

Lever is stock, I'm betting it's the actual linkage adjustment on the side of the drum since it has a weird "dual action" thing going on that works way worse than the regular single action rear drum.  I should probably give the front wheel some attention and try to true it anyway.

I've dealt with (only a few) other 2-strokes, but they were much newer and didn't come on the pipe nearly as violently as this thing does.  It's amazing and terrifying.

In reply to Sk1smark :

Tank is pretty clean but I'm wondering if HundredDollarCar is onto something with the fuel mix- I've got to be running a kind of crazy amount of oil through it with the oil injection working and premix in the tank.  Maybe I'll drain the carbs and see what the stuff coming out looks like.  It's also possible that the aftermarket petcock doesn't flow enough, in which case I'd need to find a good/rebuildable used one since mine is really toast and resisted my attempt to rebuild it.

In reply to ¯\_(ツ)_/¯ :

I would be surprised if the petcock weren't flowing enough. I'm sure it's possible, I've just never encountered it on the bikes I've had. How does the oil injection work on these things? It surprises me that it runs so well on everything but WOT.

In reply to Sk1dmark :

It runs great at WOT too... just not after a few minutes of running down the road.  The oil injection pumps straight through the crank bearings into the lower crankcase, as well as through some small ports closer to the cylinder walls.