Intermittent starting problems

Well, to make a long story short, my project bike was ready to fire up after many repairs. One of the mods that I did was to replace the bars to drag flat bars. After starting the bike and running it for a bit, I was checking the routing of the control cables, and found that the throttle cable was getting pulled when moving the bars to one side. So, I removed the tank and re-routed the cable, then put tank back on and tried to crank it over. Nothing, just heard the starting circuit cut-out relay click. But, after a few attempts, and tracing the starting circuit wiring with my multimeter (nothing seemed amiss), still nothing (battery is fine too, checked that first). One thing I did notice when trying to start it was a kind of "chuffing" noise, almost like a air sound, coming from what seemed to be the left side of engine on one attempt to start it. Could this be the crankcase breather having a blockage? Would that prevent the bike from turning over? Or would it be causing some other issue, like fouling the starter motor? Electrically, the bike checks out fine, so unless I loosened a wire in the harness when replacing the tank, I can't think of anything else. Oh yeah, the starter worked when I shorted out the terminals, and the bike has a new starter relay. Thanks for any help.

 

You might check the starter brushes.

Over full of oil or oil and gas mix.

Sorry not much help.

 

Before I got too deep into tearing things apart, I'd double - even triple-check the battery. Maybe even try jumping it off a known good battery.

After that, I know the starter switch can be very flaky on my bike. But if you're hearing the solinoid click, I doubt its that. I also don't think you'd get the click if the sidestand switch was bad, but it wouldn't hurt to check that.

Can you turn the engine by hand (with the nut under the left engine cover - observing all safety precautions, of course), or is it possibly seized?

 

i had a very similar problem. it was the starter button. kept not making contact.

 

Ain't that annoying , well since you shorted the relay and ok sounds again like the relay? but as you put on a newie awhile back i really would look at the brushes in the starter motor to see if they are greased/oiled up as that can be also a intermittant thing.

you mentioned the relay clicks , so i wonder is it clicking in fully? a test for that would be to apply 12v direct from the battery to the relay [bit of wire to the energize bit] to see what happens and if ok dat does meen a high resistance from the switch/wires.

get at it flyfishwm

 

[forgot] And no to the breather , that will not stop it start .

 

Solenoid is bad most likely.
It happens. I had a bad sparkplug once that drove me crazy for days. It was brand new out of the box.

Nachoman

 

Thanks for the suggestions. I have a hunch that it's either the starter relay or the solenoid, but have to fo more tracing. Was also thinking that it could be a faulty connection under the tank along the wiring harness. Geez, I hate transient electrical problems, they are so hard to trace down and fix. I will post up what it was when i find the problem, along with some pics of the bike.

 

make sure to follow up please and let us know what it was.

 

yeah i get this same problem , some times it starts some times the starter spins but not the motor and the other times the start solinod just clicks lol. these only really happen when the bike is cold so i normally just push start the damn thing lol :lol:
cheers brenton

 

Well, after much wire tracing (continuity and voltage) and some hair pulling, I finally found the problem. It was a poor ground of the starter button, thereby not having a complete circuit. I figure that when I changed out the bars from the chrome stock ones to the painted drag ones, that the grounding of the start button housing was lost. I realized this when playing with the start circuit inside the headlight nacelle, and observed that the ground wire from the start button went to the connector, but there was no similar wire on other side of connector to ground. At first, I didn't think too much about this, because the bike did start a few times after I changed out the bars, but then wouldn't. So, I gave the start button a very good ground, by using some other grounded wire and inserting this into the start button connector. Well, when the bike cranked over, I gave a "yahoo" and did a happy little jig!! Now the bike starts EVERY time, and all I have left to do is synch and tune the carbs, but until I do that, it's running not too bad. Although, after putting on my stainless front brake line, I found out that the front rotor is probably warped! Just another thing to fix!! Oh well, at least I can now enjoy the great riding weather, for the time being at least.

So far, the work I've done to this bike:
- rebuilt seized caliper
- rebuilt master cylinder
- replaced back brake shoes
- new spark plugs and caps
- changed oil in engine and shaft drive
- changed air filter
- cleaned carbs
- installed stainless front brake line
- installed new headlight with replaceable bulb
- had tank repaired (leaked), bondoed over removed badges and edges, and repainted
- sealed petcock to mounting area (was leaking because not flush)
- re-routed control cables due to bar change-out

I don't have any pics yet of the completed, running bike, but will post some up. I have learned alot about fixing it, and have [mostly] enjoyed doing it. Now I don't have to worry about the mechanical, at least I hope not, and just ride!

 

What kind of bike are you doing all of these wonderful things too? Any pics to share??

 

Forgot to mention, it's a 1980 Maxim 650. Pics are soon to be posted.

 

Good onya flyfsnwmn , made me laugh at the yahoo jig , i ain't had one yet via the seca as it still is not on the road as yet but my last jig was when i "worked" the international space station on vhf radio....

can't wait [hopefully] for my next yahoo jig via the seca and watching the tacho climb up