The Hodaka Club Forum

Hi, I'm back had some time to mess around with the Ace 100. If you remember my last post. Bike dies after a few minutes of riding. New points, new condenser, cleaned carb, cleaned petcocks, still dies. Last night I swapped out a coil (under tank) still died. Ahhhh I'm going nuts. Exhaust seems fine. Only thing I can add is that when its about to die if I pull in the clutch and give it throttle it will stay running and rev, but as soon as I put it back under load it just peters out. My basic knowledge is exhausted and I'm missing this awesome cool ohio summer we had this year!!!. Any help would be greatly appreciated. Could it be the other coil on the stator? Lost in Ohio...

How well does it run out of gear, what happens when you go from an idle to a cracked throttle? Does it idle? How long will it run without being in gear? How well does it start? You could be way too rich on the bottom or too lean. -----------------Clarence

Hi Rusty,
I skimmed your old thread - seems like you have a lot of the electrical covered, which brings us back to carb...
Is your carb still overflowing? You had also mentioned fuel coming out of your exhaust port and the overflow
Did you check for wear in the typical places (needle jet/jet needle/slide/non-sealing float valve/float height). Are things jetted stock?
Like Clarence mentioned, it might be time to analyze a bit on the carb symptoms.
Does it start an idle easily? Will it die after a few minutes at idle, or only under load? Is there a spot on your throttle that is particularly bad (1/8, 1/4, 1/2, WOT)?
Definitely have a clean air filter that is not over-oiled, yes?

Rusty wrote:Hi, I'm back had some time to mess around with the Ace 100. If you remember my last post. Bike dies after a few minutes of riding. New points, new condenser, cleaned carb, cleaned petcocks, still dies. Last night I swapped out a coil (under tank) still died. Ahhhh I'm going nuts. Exhaust seems fine. Only thing I can add is that when its about to die if I pull in the clutch and give it throttle it will stay running and rev, but as soon as I put it back under load it just peters out. My basic knowledge is exhausted and I'm missing this awesome cool ohio summer we had this year!!!. Any help would be greatly appreciated. Could it be the other coil on the stator? Lost in Ohio...

When it "peters out" under load, does it seem that it is running out of gas?
Try this for laughs:
Run the engine until it starts to exhibit the problem.
Then, with the clutch pulled in, have someone else (unless you have 3 hands) put the choke on.
Quickly put it under load and see if the thing runs better (does not want to die)

If this works, I would suspect a bad main seal. It is possible that when you disengage the clutch you are moving the crank "into" the seal and it covers whatever space that is present when the clutch is engaged (unless it really IS the carb). I know it is a wild one, but it is worth the try. Stranger things have happened to me.

Good Luck.

Check the vent hole in the fuel tank cap gasket. If the fuel tank is not properly venting to the air, as fuel is drawn out of the tank a vacuum will form in the tank -- which stops the flow of fuel to the carb. (This recommendation doesn't match your reported symptoms all that well, but the check takes about 10 seconds.)

Ed
PS: I'll ponder on the symptoms as I drive around to do errands today.

Hi Rusty
Go to this thread (Main Jet setting at 4000 ft Please Help) on July. Its on the main page still. I had the same problem with my Wombat. Read through it maybe it will be of some help. It sure helped me and my bike runs great.
Thanks
MTRob

Thanks all. I will take your advice next time I'm at my friends garage where the bike is located. Then I will report back. When I get off work later I will answer some of your questions. Thanks, I'm beginning to think it is some sort of carb issue.

Hi, Still not been back to my friends. This weekend I hope.

PEP to answer some of your questions. Yes, no problems starting, idles fine. When it's running it pulls through all gears very well. To my knowledge no weird spots. I pretty much ride around town, so I rip through the gears pretty fast then I'm usually in fifth. Yes still dumping gas and my petcock broke on top of everything else AHHHH I had an old one laying around. It's different (does not have indents for orings) and it leaks badly so on top of gas leaking from carb it leaks there too Bike always ran great, pop wheelies plenty of torque for a 6 foot 185 pound man til I top out in 5th around 35-40 which seems low, but could be my gearing. Then I had that problem with the points burning out. I really like fixing and building things, but I am at my wits end. Also yes I took out the air filter and re oiled it, lightly. Its just a piece of foam in there someone replaced, but never had a problem before.

Bullfrog, I can blow through the vent hole

MtRob, I'll look for your post

I have never messed with the jetting ever.

Is the carb leaking out of the overflow?
If so, your float valve might need replacing, also make sure the floats are set right (parallel with bottom of carb). Make sure that slide is not gouged up.
You can check the float valve by placing a tube on the fuel inlet, gently blow through it with floats down, then raise the floats - this should block the air flow (fuel flow) when the floats are up/parallel. Cheap part, easy swap

Ooooops. I didn't review enough of the thread prior to my last response . . . now I have. A leaking carb is a non-tunable carb. You MUST find the cause of the leaking and fix it. It is almost certainly something related to the float valve system. Needle and seat may be worn. You might have a fuel-logged float. Float level could be set too high. Grunge in the float valve prevents full shut off by the float system (you do have an in-line fuel filter, right?).

Ed
PS: There are useful tech articles regarding Mikuni carbs in "The Resonator Revisited" - the Hodaka Club Newsletter. So another aid in fixing youur problem is to be a Hodaka Club member.

Thanks guys! I will go over the carb with a fine tooth comb. Hopefully tonight.

"Is the carb leaking out of the overflow?" Yes, I'm pretty sure

I will reset the float and examine that area and parts. The float is good, I've shook it and it doesn't have any gas in it.

Thanks for the tips, I'll get this dang thing figured out before summers over...I hope

Rusty, I have found it frustrating to work on a leaky float valve and valve seat as each failed attempt to clean it up means another removal/install of the carb. I found it helpful to set up the carb on the bench and put a fuel line to it, elevated from above. I have just tie wrapped the carb to a board and placed the board in a vice. You can shim it up to make it all level. Then add fuel and make sure that it is going to seal. You can also remove the float bowl and gently lift the float to activate the float valve and see if it is shutting off the fuel flow.

I have had several valve seats that were corroded to the point that they would never seal. I chose to just order new parts and be done with them. I believe that there is an article in the Resonator Revisited (like Ed pointed out) that describes cleaning up the point on the float valve should it have a groove worn around the tip.
Dale

Oh yeah, and another way to check those floats is to place them in a bowl of gas (or water) - make sure there's no pinhole leak...but it sounds like you've confirmed this.
You are close!
-Laurie

Eureka!! (I think). It's always some dumb oversight and I've been cussin at this poor thing for about two months. I must have not unscrewed the float valve last time I cleaned the carb. Found a bunch of gunk/rust under there. I have a new fuel filter, the last one was shot and I must of overlooked that!! Hopefully be back at my friends today after I clean set float height and reassemble. Will report back then. I have a question about tuning the carb. In the manual it says to set using tpm, as you know there is not a tach. You guys have a good technique for adjusting the carb??

I always had a bit of problem hearing "X" rpm too. Perhaps it will be helpful to say that when you are tuning idle speed and pilot air screw adjustment . . . you are listening for an engine speed which is not so low that it makes you think it might die in the next instant . . . and an engine speed which is not so fast that it just seems, well, too fast if you were sitting at a stop sign and some nice folks were on the sidewalk watching/listening. i.e. "what idle speed just seems right?"

I'm glad to hear you found the cause of the over-flow. Though it is good to keep in mind that gunk in the float valve is really a symptom of dirty fuel AND poor filtration. Sounds like you have a handle on that with the new filter.

Ed

Thanks Ed, Yes I had changed the fuel filter, and cleaned the carb. I must have neglected to take out the float valve
Your description of carb tuning is how I did it before, thanks!. Carb all back togther just waiting for my friend to call.

WoooHoooo!!!!

Thanks everyone that worked with me on this. I learned more about my bike, than I did before. I think I need to readjust the carb. Might not of been warm enough. Fires on the first kick every time! It just wants to be a bit sluggish at half to full throttle. Unless I really give it hell and wind out the gears. Lets say if I'm just cruising in third, it looses pep and gets a bit sluggish. If I pop it down to second and wind it out it runs good. Thanks again. Get her tuned up and then I have a 73 Ace that became a parts bike for this one that I'm going to tear the engine down. Looking forward to that.

Glad to hear that you are getting close. It sounds like a change in Needle height might get you to where you need to be. Do you know which notch your needle clip is currently set to? The key is to determine why it gets "sluggish". Is it because it is too lean or too rich? Of course, lean is bad! If you don't know for sure, then try the needle one step richer (lower the clip 1 notch thereby raising the needle). If that makes the symptom worse, then you know it was already too rich and you can then go 2 steps leaner (raise the clip 2 notches thereby lowering the needle).
Dale