wraith Posted January 24 Posted January 24 Been having battery problems, check the charging system and it was charging at 3000 rpm 14.8 volt but now it's gone up to 15.7 volts at above 2000rpm. Going to change the alternator tomorrow. Just to refresh my memory should I look at anything else just thinking the alternator. Thanks 1 Quote
Swiss Toni Posted January 24 Posted January 24 (edited) Have you read The Stator Papers over on GSR? More aircooled than oil, but might give you some ideas. Edited January 24 by Swiss Toni 1 Quote
wraith Posted January 24 Author Posted January 24 36 minutes ago, Captain Chaos said: and this? Funny enough, I was thinking about this 1 Quote
wraith Posted January 25 Author Posted January 25 Ok, weird one. Change the alternator this morning but bike still changes at above 15volt so decided to swap battery from the kat to the et (both use the same battery) started the et up (ps both have oil cooled engines) and now charging at 14.5 volts Going to do the charging mod but just waiting for the bits Quote
Gixer1460 Posted January 25 Posted January 25 Maybe the earth / ground from battery to chassis / engine was poor in 1st instance, and moving it to 2nd bike improved the situation. An alternator will output more if the ground is poor as it can't regulate properly - well thats my theory and explains the symptoms! 3 Quote
Suzukian Posted February 1 Posted February 1 On the air cooled bikes, Suzuki ran the battery ground wire to the painted bolt hole on the engine block (a horrible thing to do, relying on painted threads for a ground), the threads would corrode, and the bike would struggle to find a ground, not being able to, it would just fuck up the whole charging system. It usually takes out the stock Rec/Rectifier, which rectifies all three legs from the Stator but only regulates the voltage one one leg, allowing the other 2 to swing wildly.. This is a standard Suzuki problem. Run the ground wire to the frame (I use the bolt that holds that tank down, I sanded a spot to bare metal), get a Yamaha FJ1200 Reg/Rec off of EBLAG, run the three stator wires directly to the rectifier, and the +/- output directly to the battery. Your problems will cease. Do not use the bikes wiring harness. Get 3 heavy gauge wires and run them directly to the Rectifier. You'll have around 6 feet of wire in your harness doing nothing and way to thin for the job. I removed mine, just yanked on them, and they pulled right out. 1 Quote
Gixer1460 Posted February 1 Posted February 1 @Suzukian - you are posting solutions to problems that don't exist here - its an oilcooled engine with a unit alternator / regulator / rectifier. 2 Quote
wraith Posted February 2 Author Posted February 2 It seems to be the battery, the battery reads as fully charged but if it does crank the engine it only does it a couple of times then dies. I've put the battery off the Kat on and not had a problem since. I've put a extra earth wire on anyway (old air cooled bit ) and just for the hell of it I'm going to do the charging mod when I get a spare minute or two. But the problem looks like the battery. 2 Quote
Gixer1460 Posted February 2 Posted February 2 (edited) You're not the 1st or will be the last, to get caught out by the good / duff battery situation! Edited February 2 by Gixer1460 1 Quote
Suzukian Posted February 2 Posted February 2 On 2/1/2026 at 6:09 PM, Gixer1460 said: @Suzukian - you are posting solutions to problems that don't exist here - its an oilcooled engine with a unit alternator / regulator / rectifier. Does your Stator have 3 wires coming out of it? Does your Reg/Rec has three A/C inputs and a +/- D.C. output? Oil Boiler or Air Cooled, this is what I have seen. On some Suzuki's they had "Hot Wire" protection circuits, don't know about that. "An alternator will output more if the ground is poor as it can't regulate properly"...that is not how electronics works. Look up Kirsschoff's Law. Good luck. I'm anxious to read how you end up fixing this. Best of luck to you. :) Quote
Duckndive Posted February 3 Posted February 3 18 minutes ago, Suzukian said: Does your Stator have 3 wires coming out of it? Does your Reg/Rec has three A/C inputs and a +/- D.C. output? Oil Boiler or Air Cooled, this is what I have seen. On some Suzuki's they had "Hot Wire" protection circuits, don't know about that. Oil Boilers have 2 wire Alternator 2 Quote
Suzukian Posted February 3 Posted February 3 Thank You for educating me on this. I really appreciate it (I'm being extremely sincere). The ground wiring on a circuit like this would have to be very well connected, or that regulator will burn up. Would you please post the year and model of your bike? I'd like to study this more, for my edification, and to prevent stupid non sequitur posts, on my part. . 1 Quote
wraith Posted February 3 Author Posted February 3 They are all the same on all the oil cooled engines, so you're looking at 1987 to 2005 (I think 2005 was the last oil cooled bandit engine) The ground/earth is not a wire from the alternator as it bolts straight to the engine via 3 M10 bolts and you have two wires coming from it a red and a orange basically. And for more information for you have a read through the charging mods for oil cooled, it's one of the sticky threads at the top 2 Quote
Suzukian Posted February 3 Posted February 3 (edited) Thanks!! I just read the link below, Geeze, I thought the air cooled systems were designed poorly. I think I'd consider making a Wheatstone Bridge and doing the whole thing from scratch. There must be almost no voltage at idle. Link: https://oldskoolsuzuki.info/archives/2515 Edited February 3 by Suzukian Quote
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