Total loss ignition

[zuluwiz]

I understand that you want to save weight, but the 1100e engine makes so much power 5 pounds won't be noticable. If you really want to cut weight, find a way to get rid of the battery. That would be worth 25-30 pounds.

[Steve]

Wow. It has been quite a while since I have seen this much MIS-information in one thread.

I like to deal as much as possible in facts, so I grabbed a digital scale and went to the shop.

Let's start with the (edited) original post, which outlines the objective:

I was wanting to remove the charging system off of an engine. ... I was planning on removing the stator itself and the regulator. Leave the flywheel and starter drive.

OK, the first guess is mine, so we'll settle that one first.

I know that drag racing is all about acceleration, and that is achieved with more power or less weight. However, leaving off the stator and regulator is what, about a pound? Is it <that> critical?

The weight of a GS850 stator (and its wiring) is 1 pound, 9.3 ounces.
The weight of a GS1100 stator (and its wiring) is 1 pound, 14.3 ounces.
I could not quickly find a stock regulator. Few would argue that an SH775 regulator weighs more.
An SH775 regulator weighs 1 pound, 1.7 ounces.
The total weight of a GS1100 stator and an SH775 regulator is 3 pounds.

The stator and rotor weigh well over a pound. Std GS1100 rotor is 5.2 lbs and a Kat rotor weighs 4.65.

Probably quite true and accurate, but re-read the original statement, he is leaving the rotor in place and only removing the stator.

If you really want to cut weight, find a way to get rid of the battery. That would be worth 25-30 pounds.

The first part of that isn't so bad. For the short durations that it will be used, a lithium pack will weigh next to nothing, but the second part is absurd. The weight of a stock 12v 14Ah battery is 8 pounds, 2.7 ounces.

Bottom line: He asked about the practicality of going total loss by ditching the stator and regulator. Yes, that's entirely possible. The fact that he will only lose three pounds in the process leads to questioning the practicality of the project. That may have led to the suggestion of losing another 8 pounds by replacing the battery. OK, maybe only 7 pounds, because a lithium battery does weigh something.

I asked the question earlier: "Is it <that> critical?" I'll ask it again, but this time, we know that we are discussing just 10 pounds.

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[limeex2]

Thank you for the correction. I've been away for awhile and got a little excited that I may even have a good tip. I seen a post from Rapid Ray too. Good to hear from him.

[GregT]

If it was me - and I have experience roadracing several makes of big fours both with and without the rotor - I'd hedge my bets.

I'd do a rotor hub with the starter clutch attatched - the lightest possible crank end with a starter fitted.
But i'd also try a full rotor before deciding which setup to use in which conditions.

On normal tarmac/bitumen/blacktop I'd say ditch the rotor every time for what the OP wants to do.
But on dirt - and possibly varying conditions - I'd wonder if a little more crank weight might be useful.

It's the old suck it and see again.

And Steve - it's racing. No amount of effort is too much.

[Steve]

I've been away for awhile and got a little excited that I may even have a good tip.

No worries. For those who might be changing a rotor to save a bit a weight, it's a GREAT tip, as long as the rotor fits the end of the crank.

And Steve - it's racing. No amount of effort is too much.

Yeah, although I have not done anything more than the occasional street race, I know that the pros will sweat over thousandths of a second. Especially if the 'reward' is more than just bragging rights.

.

[gs11ezrydr]

Was just trying to minimize any wiring,Not so much concerned about weight, Just a theory,is there a possible H.P. gain with the stator not being energized and placing some amount of draw,or resistance on the motor,I know some car guys have an alternator by-pass switch that turns it off and on.. Wonder if there is any info on GS motors that might have been dynoed with and without a charging system in relation to H.P.

[GregT]

Was just trying to minimize any wiring,Not so much concerned about weight, Just a theory,is there a possible H.P. gain with the stator not being energized and placing some amount of draw,or resistance on the motor,I know some car guys have an alternator by-pass switch that turns it off and on.. Wonder if there is any info on GS motors that might have been dynoed with and without a charging system in relation to H.P.

Never seen any data on that. But remember that Yoshimura thought it was worthwhile to drive the alternator off the final drive sprocket in races where they had to use a charging system....
The lighter crank is the point here.

[Tom R]

Your not really saving all that much wiring by just removing the charging system. I’d think it’d pay off in the end to just keep it if your not removing the rotor.
It’s nice to be able to just hit the start button if you stall.

[Buffalo Bill]

The stator and rotor weigh well over a pound. Std GS1100 rotor is 5.2 lbs and a Kat rotor weighs 4.65. It's also weight off of the crankshaft that the motor does not have to turn. Rev's quicker? Its why Kat rotor's are lighter. On a fully charged battery with a total loss system (stator and rotor still installed but dead/burnt out) I did a track day of aprox 60 minutes and could still electric start the bike after 60 minutes of riding with no lights.

I've considered going total loss on my track bike, and like Steve's point not much weight loss for starting hassle BS.
We sometimes cut motors at starting grid because of delays. It would be a real hassle to have to kill it, then start it again on the grid using an external starting devise.
I see MotoGP riders restarting their bikes after a minor crash, so they can get back in the race. They're not worried about the weight of a starter.
PS: 60 minutes total running time for 1 track day? That's only 3 on track sessions per track day.

[gs11ezrydr]

Thanks for all the info and opinions...Appreciated. As of now there is a 100$ basket case engine and a free ATV frame. Low if no budget...Just tossing ideas... Thanks again..

[GregT]

I've considered going total loss on my track bike, and like Steve's point not much weight loss for starting hassle BS.
We sometimes cut motors at starting grid because of delays. It would be a real hassle to have to kill it, then start it again on the grid using an external starting devise.
I see MotoGP riders restarting their bikes after a minor crash, so they can get back in the race. They're not worried about the weight of a starter.
PS: 60 minutes total running time for 1 track day? That's only 3 on track sessions per track day.

As I've pointed out earlier in the thread, it's possible to still use a starter with the majority of the rotor mass detatched. Splitting the hub out of the rotor is easy. Just drill out the rivets.
Our high compression, big cam, big bore big carbs GS1000 would restart hot using the small on-board battery.

I believe MotoGP bikes are now required to self- start - and the minimum weights reflect that.

I had a speedway car client who was sensitive enough to pick the difference in feel between having the starter clutch fitted to the crank and it left off.
That was on a GSXR750 and the starter clutch weighs about 1kg on them.

[Agemax]

I believe MotoGP bikes are now required to self- start - and the minimum weights reflect that.

Not true, all of the 3 moto GP classes still rely on external starters. None of them have, or require an "onboard" starting facility.

[zed1015]

I was wanting to remove the charging system off of an engine.Total loss Ign. I know I will have to power the coils and the dyna S Ignition.I was planing on removing the stator itself and the regulator.Leave the flywheel and starter drive..Battery power only..Any faults with it... All and any advice would be appreciated.I thinking about installing a 82 GS 1100 in an ATV. Dirt Drags ..

We run a Turbo funny drag bike.
The Orient Express Kawasaki Z900 with total loss ign.
There's no problem with what you want to do but you won't gain anything with just the removal of the windings and regulator.
The weight loss will barely be better than not wearing any underwear and will just cause more hassle having to remote charge between runs.
If you were going to do it then loosing the whole rotor etc is the way to go as that will gain a few HP at the crank.
Just be sure to keep the battery fully charged otherwise you will reduce max power.
We lose 100 hp from a 250 hp motor after the the first couple of quarters if the battery isn't changed or topped up between runs.

[storm 64]

Here is a interesting charging system set up... I'm not sure what's under the cover.