Strange Starting Problem

[6Pipes]

Hi all,

My 79 cranks right up when cold. But after I ride it for an hour and shut it off, it will barely crank over and today when I stopped for gas, in front of a group of onlookers admiring my bike, it would not crank enough to start the engine. I had to go through the humiliation of accepting a "push" to get it started and get home. I should mention that the alternator constantly charges nearly 14 volts. Now, after the bike cools off, that same dead battery cranks like a champ. It has been suggested that there is a bad cell in the battery so I'm shopping for a new one. Looking at Yuasa and Big Crank 310 CCA.

Thoughts or suggestions?

[EMS]

Don't know about that. If there was a bad cell in the battery, it would show all the time and it would not crank no matter if cold or warm. As soon as you'd put a load on the battery, it would collapse. This is a strange scenario. Never encountered that before. Usually, resistance in wiring increases with temperature and this is almost like it, but I don't think that it would have that much of an effect on a starting system. Maybe something inside the starter wiring is on the fritz.

[steve murdoch icoa #5322]

If you think your battery and charging system are working properly i would be looking at the starter.
The brushes could be binding.

[NobleHops]

When you say it wouldn't crank, was it just cranking slowly? Or was it just going *click* and not turning over? If it's the latter, then you can test the solenoid by taking a big screwdriver and momentarily bridging the two big posts on the solenoid. Obviously, don't be touching the metal of the screwdriver when you do this. If it cranks under those circumstances when it otherwise would not then it could indicate a balky solenoid. That happened on my bike - I replaced it and it hasn't happened since.

Measure the resting voltage of the battery - It should be around 12.6. If that's what it reads when this happens then it probably isn't related to the battery itself.

Also check the connections on the heavy wires - On the battery itself, to the solenoid and from it to the middle of the starter, and to the ground on one of the starter bolts just above the sprocket cover.

N.

[6Pipes]

Hey Nils,

It just acted like the battery was dead. It cranked very slow for a couple of seconds and then would not crank at all. No clicking from the solenoid. Sure wish I had the presence of mind to check if the headlight was dim when that happened. I think I will go back through all of the electrical connections this afternoon and check for corrosion. Resting voltage on my battery tester shows 12.4. Will keep you all informed.

[daves79x]

Unloaded voltage measurements on a battery tell you very little, relative to your problem. You need to see what it does when you press the starter. A bad cell will immediately collapse and voltage will drop way down. But a voltage drop can also be due to very high resistance somewhere, possibly the starter. I'd suspect the battery, bad battery connection, solenoid or the starter. Check those things first, especially if it starts fine cold.

Dave

[Rick Pope]

I had the same problem. It was a weak battery. The hot motor has better compression and thus turns harder.

To be sure, try a different battery before purchaseing a new one. I have a couple of bikes with the new Litium Ion batteies. Expensive, but a lot of power in a small package. 410 amps in the CBR-XX, and half the size of the original.

[6Pipes]

Well....I think you guys are right. Today I felt like tinkering so I checked all of the starting elec. circuitry and connections, removed the starter and bench checked it. Then pulled it apart and everything looks good. It's all back together now and the engine cranks with no problems. As the starting system appears to be in order, I'm going to buy a new AGM battery this week. Stay tuned.......

[NobleHops]

AGM is the sweet spot for price/value/performance, you cant' go wrong. Big Crank, DieHard, Odyssey, those are all excellent. Hope that's what it is!

N.

[EMS]

AGM is the sweet spot for price/value/performance, you cant' go wrong. Big Crank, DieHard, Odyssey, those are all excellent. Hope that's what it is!

N.

Don't forget Westco! They may not list a battery for the CBX, but the Goldwing unit is a perfect fit. You don't have to use the spacer anymore.

[Hondell]

Well 6 Pipes, you helped me with my cold start accel. pump problem so maybe I can help you out. Same thing started happening to me a week ago. Same senario in the parking lot too!! Got the bike home and tried cranking- slow and labored. Tore the sidecovers off thinking it might be loose terminals on the battery but no. Noticed the ground cable for the negative side of the battery was quite hot. Upon further looking the wire had been previously been heated up to the point that the copper had gone brittle and 80 % of the wire was fractured inside the insulation. I suspect because of the excessive cranking to start it when I had the pump problem, the cable overheated and ruined the copper. So far new cable = no pushing. Hope this might help you.

[NobleHops]

OK that's pretty interesting. And here's a thought: I spied a very nice quality long battery cable in my neighborhood small engine repair place, for a garden tractor of some kind. Something like $6, with nice heavy lugs sweged on either end. I bought one .

[Samelak]

Bench check your solenoid. I had the same problem and it turned out to be severely corroded on the inside.

[NobleHops]

Bench check your solenoid. I had the same problem and it turned out to be severely corroded on the inside.

+1, same here.

N.

[6Pipes]

This is interesting.....why would a solenoid that is corroded on the inside work perfectly when the bike is cold and not transfer electons after an hour of engine run time???