SH775 swap - engine won't rev over 6k

[hotrodalex]

Turning the key on only drops voltage .01v

I did a resistance test on the stator wires and the white/red wire says it's an open circuit. AC voltage test says the same thing. So I'll dig into that and see if it's the wiring or a partially fried stator.

Also, my bike is only a smidge over 400 pounds.

As for lithium batteries, I've got a Shorai and it's a lithium-iron battery, not lithium-ion. These won't burst into flames - they'll just smoke and melt down. I got it because it'll hold its voltage for like a year without charging, plus it's a bit more lightweight. I had troubles with the previous lead-acid battery so I decided to try something new. I'm a restomod guy so I just enjoy putting more modern tech on old things (I've got a '69 El Camino pro-touring car as well)

Here's a link to Shorai's charging guide: https://shoraipower.com/charging

 

[posplayr]

Mine was a Shorai as well (discharged itself into oblivion the first week). I hope they had added some basic control electronics by now.

 

[hotrodalex]

https://i.imgur.com/VQoTnWD.jpg

I pulled the stator cover off today. No signs of burn out. Could it still be bad, or should I turn my attention elsewhere?

 

[hotrodalex]

Ok so I have a couple of lights that aren't working right now either. The tail light doesn't come on with the headlights, even though the brake light works fine (same bulb). Neither do the dash lights for the tach or speedo (but all of the other dash lights work fine). In Park, neither the tail light or the front yellow bulb in the headlight comes on. The two affected wires are the gray or brown wire on the wiring diagram. They go through the ignition switch and lighting switch. The lighting switch is where the gray wire originates, and it also happens to be where one of the stator wires goes through (so the stator is only running 2/3 power unless the headlight is on?)

If I replace the lighting switch, it might solve all of these issues. I'll do some testing tomorrow.

 

[tom203]

Way back you said your stator tested bad....

"I did a resistance test on the stator wires and the white/red wire says it's an open circuit. AC voltage test says the same thing. So I'll dig into that and see if it's the wiring or a partially fried stator."

Unless it's Cajun fried, a visual test is sorta useless ..
you likely have switch issues, but hopefully you have connected the stator wires directly to the SH-775 to eliminate a switch interfering with charging.

 

[cowboyup3371]

Did you also check your fuses as the headlight/taillight are on the same circuit? Is it the older tube style or a new blade style? If the tube, keep in mind that it can be broke under the caps where you can't see it. Please test it using a test light to be sure you are getting power to both sides of it before trying to replace switches

 

[hotrodalex]

Way back you said your stator tested bad....

"I did a resistance test on the stator wires and the white/red wire says it's an open circuit. AC voltage test says the same thing. So I'll dig into that and see if it's the wiring or a partially fried stator."

Unless it's Cajun fried, a visual test is sorta useless ..
you likely have switch issues, but hopefully you have connected the stator wires directly to the SH-775 to eliminate a switch interfering with charging.

I figure since it looks pristine still, it's worth investigating the rest of the wiring harness & switches first.

 

[hotrodalex]

Did you also check your fuses as the headlight/taillight are on the same circuit? Is it the older tube style or a new blade style? If the tube, keep in mind that it can be broke under the caps where you can't see it. Please test it using a test light to be sure you are getting power to both sides of it before trying to replace switches

As far as I know, these '77s only have the 1 main fuse back by the R/R.

 

[Nessism]

First off, the charging system should be rewired to bypass the stator leg through the headlamp switch. This has been discussed countless times here and should be the first thing done when investigating charging system problems. https://www.thegsresources.com/_forum/showthread.php?254759-SH775-Install-Diagram

Secondly, as already mentioned by more than one of us, a charging system issue won't cause the bike to not rev, assuming the battery has a decent charge. If the battery has enough charge to spin the starter motor the bike will rev to redline. Running problems will only come in after the battery gets run down.

 

[hotrodalex]

First off, the charging system should be rewired to bypass the stator leg through the headlamp switch. This has been discussed countless times here and should be the first thing done when investigating charging system problems. https://www.thegsresources.com/_forum/showthread.php?254759-SH775-Install-Diagram

Secondly, as already mentioned by more than one of us, a charging system issue won't cause the bike to not rev, assuming the battery has a decent charge. If the battery has enough charge to spin the starter motor the bike will rev to redline. Running problems will only come in after the battery gets run down.

Thanks. My next step will be to re-route that stator wire direct to the R/R. Is that recommended even with a stock R/R or only with the SH775? And then I'll see if the dash lights/etc work if I temporarily bypass the lighting switch.

 

[Nessism]

Thanks. My next step will be to re-route that stator wire direct to the R/R. Is that recommended even with a stock R/R or only with the SH775?

Yes, fixing the wiring, including the grounding, should be done regardless of whatever R/R is used. Also check for resistance in the power wire leaving the R/R.

 

[hotrodalex]

I rewired the stator directly to the R/R.

But I checked the valves and swapped 2 exhaust shims and 1 intake shim. That seems to have fixed the problem. The engine starts better and revs normally now. Electrical system seems fine.

 

[tom203]

I rewired the stator directly to the R/R.

But I checked the valves and swapped 2 exhaust shims and 1 intake shim. That seems to have fixed the problem. The engine starts better and revs normally now. Electrical system seems fine.

Thanks for update...it might inspire others .