Electrical

[whisker biskket]

Ok heres the deal! my bike only starts 2 to 4 times and then wont start without a Jump or putting it on the battery tender. I have tested and or replaced everything but the starter! everything tests well within the paramaters! even when the bike wont start the battery shows it has well over 12v! while running the charging system all checks out! Stator, regulator, and circut breaker all good! all of the battery cables have been checked and cleaned. I cant quit put my finger on the problem and i am wondering if I have been chasing the wrong problem all along, could this be a starter issue like the solenoid not right? how would I check that?

 

[Hoople]

Welcome to the Forum. Need more info. Year of your bike, how old the battery is. I see your 120 cu/in. Has it been OK up to this point. Compression release, cranking PSI? Recent changes when problem started happening. Has the battery been load tested. Static Voltage across across terminals tells you very little.

 

[whisker biskket]

yes the battery is new! less then 2months! and has been load tested and checks out (MotoFactory 315 cca) The bike although a 120ci it does have compression releases and I changed the starter ring from the 102 tooth to the 66 tooth and it starts better then stock when it does! it has a high torque starter. this is an 05 bike that I have put alot of money and work in! I have had a very reputable Bike shop here in northern alabama do all the work and they are stumped to! I would like to say it is an intermittent problem but it never does it the first few starts or so it only after it been run that it does it! on top of that if i have some one give me a jump like when I am stuck, as soon as i put the cables on the battery it fires right up like it has a full charge! would the solenoid slow down or hurt the flow of current to the point it would make it act like that! because alot of good people with more knowlege then I have are stumped by this. Thanks for your help and for welcoming me to your site.

 

[Hoople]

on top of that if i have some one give me a jump like when I am stuck, as soon as i put the cables on the battery it fires right up like it has a full charge!

The fact that you can strap another battery across your existing battery and the bike starts fine sure indicates the battery is weak at that point. You may want to check the charging system.

Would you happen to know if the 2005 charging system is 3 phase? (does the stator have 2 output wires or 3 output wires) If you have 3 wires, your 3 phase and should have good charging output even when at idle. If your stator is single phase it is possible that your idle charging current is marginal.

Would you happen to have an induction DC amp probe that would enable you to check starter cranking amperage draw. That is an important number to know when troubleshooting a problem such as yours.

The first thing I would check is charging voltage at idle, at 2500 RPM and at 3000 RPM. Determine if you are single or 3 phase. I would also have to measure the cranking current of the start when both hot & cold. It is a must to know that number. I have seen starters go crazy when Hot but check fine when cold. If you do have an induction amp probe, check the charging current also.
With the above info, you will know what is going on and how to fix it.

 

[whisker biskket]

It is a 32 amp system it is a single phase! also we have put 2 batteries in the bike both new and fully charged! In most cases I believe you are correct in saying that jumping it and it starting would indicate that the battery is low! however when checking the batter it checks out and has the volts! I feel as if the othe battery helps over load the solenoid to make it work because with a full charge cold it will start everytime! but once hot it is a whole nother story! everything has checked out! on that DC amp probe would that test how my solenoid is working and does the solenoid ever impeade the flow of electricity if it goes bad? because the charging voltage checks out at idle, 2500, and 3000 rpm. I will know soon what the problem is and will keep you abreast.

 

[Hoople]

1) You said you installed 2 New (checked good) batteries in the bike with the same results.
2) You are single Phase 32 amp.
3) When you strap a second Battery across a known good installed battery, the engine spins off fine.
4) The problem does not happen when the engine is cold.

A bad starter solenoid could certainly cause the problem. But you would know that once you measured the current draw of the starter while cranking the engine.

My guess at this point is your current draw when hot is way way up there (greater than 100 amps). If the current draw is high it proves the solenoid is Good. If the current draw is very low (<30 amps) the solenoid is Bad.

First steps to finding the root cause is to measure the cranking current when Hot vs Cold.