Slow cranking speeds, conflicting symptoms.

[muldo]

Hey all...

Here are my symptoms, they don't all add up...

S&S 145" w/ electronic compression releases

Hi-torque starter (Compufire Gen II)

Brand new battery, haven't tested it myself but supposedly load tests at 330 CCA

Brand new cables.

Engine is slow to crank, unless we put a booster on it, then goes fine. Very frustrating!

Thoughts??

-Mike

[arealinvestor]

No expert here.But did you check to see if the Automatic comp releases might be stuck closed?? Some guys here were having problems with those things sticking both open & closed.Damn it must be nice riding that 145ci when she's running!!!

[claydbal]

some hi output batteries act more like a capacitor. they may give you the 330, but only for a split second, after which, they become weaker than oem. have seen this with oddesy for sure.

[luvstoride]

I've had brand new batteries with bad cells.

[mgb939]

Hook up a multi-meter to the battery, try to start engine and see what the voltage drops to. Anything below 10 volts usually wont start the engine.
As previous posted by Arealinvestor, check those releases.

[muldo]

All good suggestions...just haven't had time to get back into the shop to check anything.

How does one go about checking the electric releases? This is my first set and I am more familiar with the manual ones. Do they just vent to atmosphere or do they dump to exhaust?

Thanks all! Keep the knowledge coming! (I think it's a lousy battery myself, but we'll see...)

Mike

[BadWeather]

Auto releases usually dump to the exhaust port

[muldo]

That's what I thought...it would seem pretty goofy to pump a fuel/air charge into the atmosphere above the engine...

[mad mark]

the battery does not have enough cranking amps for that hi torque starter i went through the same problem with my tp 124 cu inch i went with a small 1.4 all balls starter and biggest battery i could fit in my battery box it takes less juice to make starter work to peak compassitey also make sure the starter and the battery each have a ground wire to a good spot on the frame and that you use good name battery cables and keep the bike on a trikle charger when not using this took care of my problem after about a whole riding season was over hopefully this will help you

[stupidglide]

Easy way to check things out;
Step#1 If you at all suspect the compression releases, just pull the spark plugs out, and crank it over. That will tell you right away if the releases are the culprits.

Step#2 If that aint it, start at the battery, and physically (as in take apart) check EVERY connection in the starting circuit, clean them, and re-assemble them with a thin coat of silicone dielectric grease, and as you go, try to start the bike each time you service the connection. That will help you determine what the issue is, and if its related to a poor connection, or loose wire.

Step#3 When that is done, if you still ain't got it, snag your friendly neighborhood factory sevice manual, and start the test and troubleshoot portion of your program, and test each physical component, one by one.

If this don't solve your issues, then I would suggest stocking up on your favorite adult beverage, and imbibing in a copius manner. (polite way of saying get snotty drunk) and spending the rest of your night with a tub of ben and jerry's, a box of puffs, and a chick flick.

If that fails, put an ad in the local "alternative" newspaper, for a good witch doctor, or voodoo queen, and a moist dwarf, and pray that the chicken blood don't stain the paint, and the chicken bones don't scratch nothin'.


Seriously, though? If you follow all those steps, you WILL find the problem, and you WILL fix it.

Besides, the combination of witch doctor, and moist dwarf, would probably make great entertainment.

[muldo]

Thanks for all the fantastic suggestions folks, here's what we've done so far:

I did my own load test on the battery (rather than taking the vendors word for it...) and we have a steady 330-400 CCA at about 12.2 volts. Battery is good.

Bike is a 1990 FXRT, by the way, and just had a total teardown and rebuild. All battery cables/connections/ground straps/serrated washers are brand new.

This starter had no problem turning over a 113" with 10.5:1 pistons and manual compression releases. Turns over fine with no spark plugs.

We disconnected the compression releases and the motor will not turn over at all, so they are working but still aren't enough.

Our current solution is to relocate the oil bucket from behind the rear jug to a false muffler on the left side, and install a second battery under the seat. We anticipate that this will be enough juice to turn over a freight train. (Not quite, but pretty close...)

Will keep everyone posted!

-Mike

[muldo]

One thing I can't figure out...

P(watts)=V(volts)*I(amps)

2 kW = 2000 W

2000 W / 12 V = 167 A

Even if we assume 80% efficiency we still only need 208 A...

I dunno, maybe I need bigger cables.

-Mike

[mike92]

My old Dyna did that and it turned out to be a bad starter.

[mad mark]

did you ever get this find the problem if so what was it