GL 1500 Compu Fire trivia quiz

[ct1500]

I have a way of knowing if a GL1500 has a CompuFire HO alternator installed without any panel removal or test instruments involved.
Anyone care to venture a guess how it is done?

[gford]

Charges at 14+ at idle?

[terryt]

The lights don't dim when every thing is on at tick over

[DenverWinger]

Ask the Owner?

[CrystalPistol]

Lay down on your back and ease your head under the bike (or trike) and look up … or use a mirror.

[ct1500]

Lay down on your back and ease your head under the bike (or trike) and look up … or use a mirror.

Negative, no cheating involved. You have seen it hundreds of times but never made the connection to an OEM ride.

[blupupher]

sound?
need 20 characters

[4given]

Does it need to be running for this quiz?

[ct1500]

A winner on the other site. The answer is:
One of the first 1500's I ever worked on was for a man who wanted his Compu Fire installed. After brakes, belts,exhaust,carbs,fluids,fork seals,driveshaft boot and of course the alternator It was time to back it out of the stall for him to pick it up that day. When I hit reverse I could here the engine idle drop way down. Uh ooh, something not right here was my first thought until I made the connection to the CompuFire claim of 60A at idle. Sure enough those alternators can kick out some serious amperage and I estimate it to be about 35A more at idle when using reverse.

The reverse system draws about 80A and in your OEM 40A equipped ride the alternator is near or over capacity from the get go so all current for reverse is direct from the battery with no extra current from alternator hence no idle RPM drop.

[4given]

So if I’m understanding what you are saying, no idle drop means OEM alternator. If the idle drops it’s probably a Compu Fire?

[ct1500]

If I recall now the drop was substantial maybe on the order of around 200RPM for the CompuFire, OEM alternators no drop.

[blupupher]

So if I’m understanding what you are saying, no idle drop means OEM alternator. If the idle drops it’s probably a Compu Fire?

Correct.
With the stock alternator, it never had enough load at it's max to cause a strain on the engine, the electronics would just use the battery instead.
With the Compufire, it can put out more, and that higher output causes the engine idle to drop due to the increased drag.

Kind of backwards of what you would think it would be.

[CrystalPistol]

A winner on the other site. The answer is:
One of the first 1500's I ever worked on was for a man who wanted his Compu Fire installed. After brakes, belts,exhaust,carbs,fluids,fork seals,driveshaft boot and of course the alternator It was time to back it out of the stall for him to pick it up that day. When I hit reverse I could here the engine idle drop way down. Uh ooh, something not right here was my first thought until I made the connection to the CompuFire claim of 60A at idle. Sure enough those alternators can kick out some serious amperage and I estimate it to be about 35A more at idle when using reverse.

The reverse system draws about 80A and in your OEM 40A equipped ride the alternator is near or over capacity from the get go so all current for reverse is direct from the battery with no extra current from alternator hence no idle RPM drop.

Understand I do, but I almost never use reverse so it didn't occur to me. I thought about it, might be so too. I didn't think about it pulling 80A.

I've used it once when making a U-turn on a country road after seeing a buddy go belly up in my mirror, my front tire dropped off the pavement on the far side and I had to "back up" pulling the front tire back up out of the ditch. it pulled a load that day I bet. I've used it to back up onto my ramps but I stood beside it and used my left knee against the fender to "help" it. Usually when parking, I'll swing a "U" in front of the space, stop, drop feet after selecting neutral, and give a push backwards into the space. If it was a bike, likely would use reverse more.

[4given]

If I recall now the drop was substantial maybe on the order of around 200RPM for the CompuFire, OEM alternators no drop.

That’s very interesting. I will be checking that out.

[4given]

If I recall now the drop was substantial maybe on the order of around 200RPM for the CompuFire, OEM alternators no drop.

Thanks ct1500. I didn’t notice it until I read this post but my 96 Aspencade does exactly this and according to the volt meter is putting out 14.1 Volts at idle. So without looking at the alternator I’m assuming it is a CompuFire or something similar.