Anybody know Hondamatics?: Sprockets forum: Grassroots Motorsports Magazine

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Sept. 9, 2009 4:30 p.m. alex HalfDork

I'm doing my bass player a favor and tuning his '78 Honda Hawk 400A. It came to me in a rough state of tune, which I've sorted. Sitting still, it does everything right: idles smoothly, pulls cleanly through the rev range, settles back down without drama.

But riding the thing is almost comical. In gear, wide open throttle and... almost nothing happens. I have the urge to pedal my feet to get it going. It doesn't bog or stall, and it doesn't rev like it's slipping. It just. Doesn't. Go. Or it does, but barely.

I know I'm dealing with a 31 year-old, 395cc, de-tuned-by-10-hp automatic, so it's not going to make me see God while ripping my shoulders out of their sockets with its explosive power, but that just doesn't seem right. Or is it?

I'm totally unfamiliar with these automatics. School me.
Sept. 9, 2009 8:36 p.m. xci_ed6 Reader

I don't know anything specific about the Hondamatics, but just wondering if you have covered all the basics.

Does it have a low range? I saw a cb750a the other day and it still had a shift lever, but no clutch.
Sept. 10, 2009 12:52 a.m. BoxheadTim Reader

The 400A should have low & high ranges like the 750A. I'm just wondering if alex has just found out why there weren't a massive sales success or if it is an actual fault with the bike.
Sept. 10, 2009 9:10 a.m. alex HalfDork

It's a two speed, with a regular shift lever and no clutch. No external hi-lo on the gearbox like on some early DOHC CB750/900s. It's dead simple.

Tim, I'm wondering the same myself. As smooth as it runs in neutral, with no drag from the transmission, I'm beginning to think everything's operating normally.

Notice I didn't say 'right.' Nothing 'right' about this...
Sept. 10, 2009 9:26 a.m. BoxheadTim Reader

The two speed is actually your L-H range selector. The lower gear should give a little more poke and the higher one should give a little more spend. Eventually...
Sept. 10, 2009 10:02 a.m. 44Dwarf HalfDork

Seem to be a common thing with hondamatics. The clutch is a torque converter so changing the engine oil is a must.
Tune up seem to afect the motor output greatly. Carb swaps are common to add get up and go power.
Sept. 11, 2009 7:38 a.m. Rusnak_322 Reader

My aunt has one. She had it when I was first riding mopeds when I was 14 years old. I thought it was dog slow then back then.
Sept. 11, 2009 9:13 a.m. Grtechguy UltraDork

I don't know if I could ride without a clutch....
Sept. 11, 2009 10:01 a.m. alex HalfDork

Yeah, when I went to start it I yanked on the left lever on the handlebar and thought, 'oh boy, something's really wrong with the clutch...' Then I remembered: that's the parking brake. Fortunately, Honda was smart enough to include a lockout so you can't accidentally grab a giant handful of brakes trying to clutch-in and shift down out of habit. I wonder how many of their test riders dumped it before they figured that out.
Sept. 11, 2009 10:06 a.m. neon4891 UltraDork

Sorry to thread jack, but about 20 years ago my dad had a friend in a wheel chair and had a big hondamatic with a sidecar and the controls going to the side car. I was told that it was a very interesting set up.
Sept. 11, 2009 11:54 a.m. xci_ed6 Reader

Grtechguy wrote:

I don't know if I could ride without a clutch....

haha, I have trouble with that. I tried to ride a friends ATV that has a 5-spd and an auto-clutch, and I couldn't figure out how to shift it. I've only been riding motorcycles with clutches for more than a decade.
Sept. 14, 2009 5:41 p.m. pinchvalve UltraDork

It's odd that the revs aren't climbing. Are you sure the butterflies are opening? Are the secondaries operational? Are the diaphragms in working order? Is the clutch cable...oh wait.
Sept. 14, 2009 5:49 p.m. alex HalfDork

Revs climb fine in neutral. It's just like a normal old Honda twin when it's sitting there on the stand. It's the load from the transmission that slows it to a crawl.

Talking to my old boss from the motorcycle shop, he says this is pretty much par for the course. Being a real stickler about oil viscosity and fill level may help a bit, but only marginally. I don't know what's in there, so I'll leave that up to my bass player.

Anyway, that's not why it came to me, so I can brush off my hands and ship this one back. (Hey what do you want for a free service?)
Sept. 18, 2009 1:35 p.m. 16vCorey SuperDork

Ignition timing? Sounds like it might be retarded, since it revs with no load but won't with a load. I've only ridden a CM450a once, and it was slow, but not nearly as bad as you're describing.
Sept. 24, 2009 1:22 p.m. Rusnak_322 Reader

just came across this thread - http://dotheton.com/index.php?topic=9888.0