The Hodaka Club Forum

Hey everyone, i recently finished rebuilding the engine of a hodaka ace 100 model 92. It ran great, the engine sounded beautiful. i wasn't sure the electrical system ever fully worked, i never tested it. anyways, recently the key ignition switch on the side of the bike jammed and i pulled it off and hotwired the ignition circuit through a basic throw switch. now the engine sounds fine and idles great, but if i rev the throttle too high it will stop combustion, get a really hollow sound and die. it sounds like a carburetor issue, but the carburator hasn't changed, just the switch problem. My main gues is that the ignition timing is off and it is only really a problem at high rpms.

Second issue is with the shifter. About a week ago, if you tried shifting gears it would either over shift or under shift and, rather than going into gear, it would hit the miniature neutral in between gears. I took the shift cover apart and found that the shift arm had about half an inch of play to either side even when "in gear". i took it apart, put in new spacers and tightened everything up. now there is significantly less play, only about 1/16th of an inch in each direction. It shifts much better, but still has the same problem of falling in between gears.

Any thoughts would be greatly appreciated
-Thanks

Hard to say about the shift thing, but could be the two springs that bracket the ball receiver are sacked, broken, or whatever so the ball receiver won't stay centered. Particularly as you said it had a lot of slack in it and finds neutral too much. With the shift cover off and the control rod free, find a gear. Doesn't matter which one. When it is in gear, try to gently move the control shaft either in or out. If it moves without any sense of spring tension, it could be the springs. If it feels firmly in gear without any real play without more force, it is probably the adjustment under the cover.

As for the electrical, one needs to ask if it did this before removing the switch. If it did, it isn't the switch. If it didn't, I would have to guess it is the switch, but I can't think of why it would act this way. The switch is not magical. Actually, it will run without a switch at all. All the switch does, aside from lights, is act as a kill to run a wire to ground. Your new switch should be doing the same thing.

Cutting out at high speed sounds like a weak spark. High engine speeds can blow out the spark. Mir be time to test primary and secondary coil for function, test the condenser, and look for corrosion under the flywheel.

Are you using a fuel filter? It could be that your main jet is plugged and when you apply the throttle, you are getting all air and no additional fuel.
Dale

it didn't have a fuel filter when i got it, so i didn't think it was necessary, so no it doesn't, but if the main jet is plugged wouldn't it also cut out at low speeds too. The other thing is that it isn't necessarily at high rpms when it dies, sometimes it'll be idling, and i can kill it by cranking the throttle. but it definately does sound like it is only getting air so that is definately possible.

My other question is a little out of the blue, but is there a small hole just above one of the engine bearings to allow gas in to cool the bearing, because i also rebuilt a 1969 vespa with a fairly similar engine and it had such a hole and you had to line up the seal with the hole other wise the bearing would over heat. I am just a little nervous because i can't remember for the life of me if the hodaka had one and i want to make sure that i put it back together correctly.

Yes the Hodaka has a lube hole too on the flywheel side . Careful not beat the seal in past the casting . The only Hodaka that dont have that hole is the 03 Wombat.

Rich

If you seated the seal flush, you should be okay. It is mostly the bearing race itself that tends to overlap the hole, but that is a design issue. I work around that by relieving the race with a small groove, aligning the groove and hole during installation, and hogging out the aluminum drain hole a bit. On the other hand, stock setup does work. It is just that when rebuilding my 97 recently, everything was fine except the flywheel side bearing which was blue. Not good. So I took steps to up the fuel flow in that area.

Thanks everyone. is there a way that i can check if i blocked the lube hole without splitting the engine casing.

Also, i had a one of my motor head friends look at the issue where it would stall if i pulled the throttle too fast. he says that its probably that the magneto is weakened and can't supply enough power to get spark if i rev to fast. however, i'm a little confused as to that theory because it can rev all the way if i pull the throttle slowly. any thoughts?

archdukeferdinand wrote:Thanks everyone. is there a way that i can check if i blocked the lube hole without splitting the engine casing.

Also, i had a one of my motor head friends look at the issue where it would stall if i pulled the throttle too fast. he says that its probably that the magneto is weakened and can't supply enough power to get spark if i rev to fast. however, i'm a little confused as to that theory because it can rev all the way if i pull the throttle slowly. any thoughts?

Sounds like too much air too fast... which means plugged or restricted jets. Only the pilot supplies fuel in all throttle positions. The main jet supplies fuel at the 3/4 to full throttle range, which is why Dale indicated that it might be a plugged Main jet, based on your description.

Roger

Thanks, i will check that. also does anyone have a useful wiring diagram with colors. i am only 16 and never rewired a bike before and am kind of nervous to do so. Also what kind of battery does it take. ALso, does anyone know where to get a high performace carburetor for these bikes, there are a few hings wrong with mine and i might just want to replace it. Sorry, kind of alot of questions, so any answers would be appreciated, thanks everyone for being so helpful and responsive. great forum!

Pretty sure you can see the fuel passage with the cylinder off looking straight down.

Wiring diagrams can be found under the FAQ/Howto-Technical Tips section of the StrictlyHodaka.com main page.

Be careful which diagram you use though... depending on the year your bike was made and the exact model, the wiring may be slightly different. Early Ace 100's used the same wiring as the Ace 90. Later models incorporated an Emergency Toggle Switch on the left underside of the headlight bucket. If you have no switch, it's either been removed, leaving the mounting hole, or it never had one. If you can verify it never had one, you would use the Ace 90 Diagram. Otherwise, the Ace 100 diagram.

If you build your own, it is highly advisable you use the same colors. You will appreciate that later when troubleshooting electrical problems. And you can get the original type connectors at vintageconnections.com. But there are a couple members here who could make one for you for a nominal fee, (that's a passive invitation for them to chime in). You just need to know exactly which one you need.

You can purchase batteries here or local to your area. Just needs to be a 6v 4 amp/hour battery that fits into the battery box. I've been using a sealed lead acid battery with good results lately rather than the standard battery.

$0.02

Roger

Just email me with the Frame # and I' ll send you a new wiring harness for free, either 90 or 100. I make them from original copys and have them all.
Using the original colored wire and ends that just plugs in. Always want to see a younger Hodaka fan succeed in there fun for learning what we already
know.
MTRob

That's awesome MTRob. My hat's off to you for helping that young man. I'm sure he will someday pay it forward.
Cheers,
Dan

Hey guys, thanks for all the help. The other day i went to open up the carb to check the jet and the first thing i saw was the main jet sitting in the bottom of the float bowl. Haha, that was easy. Anyways, the engine runs beautifully, and the shifting is getting really close, im just tuning it now.
Here are some photos from along the way, finally got to downloading them on to my computer. I have a video of the engine running, but i couldn't figure out how to upload it.

Here is the bike as i bought it. Here is the engine when i was reassembling it after the rebuild