77 xs400 starting problems

there is a way to advance and retard time then?
Yes, there are screws on the round points plate that allow you to rotate the whole plate a certain distance in either direction to adjust the timing both cylinders at the same time (similar to turning a distributor on a car).
The old valve cover that I inherited has the tach cable stilll attached while the one on the bike isnt there at all. I looked at seeing if there was a way to reuse the old one but it seems like the two are mated and it would involve some work to install it on the bike.
The tach cable is secured with a screw. To remove the cable from the top cover, remove the screw completely and pull on the cable to extract it. In my experience, the cable is a tight fit, so you may have to use some force. Putting the cable into the new cover involves cleaning and lubing the cable, inserting it fully into the drive hole (may have to push hard to get it to seat) and then reinstalling the screw.
Done done and done. Runs like a top now, kicks over real easy and the electric start turns over immediately. Thanks to everyone who gave me pointers and advice. Im gonna ride this thing in its current configuration for a while and see what speaks to me. I do wanna upgrade the headlight now though from the incandescent to led. Anybody care to suggest a drop in replacement ?
Im gonna ride this thing in its current configuration for a while and see what speaks to me
Usually I am the one talking to the bike. If parts of my bike start talking back I think it will be time for me to hang it up! Honestly, good job getting it back in action.
Alright gentlemen yall deserve an update so here it is.

Rode it to work a couple days in a row to see what else would shake out and some things immediately jumped out to say hello.
Hanging throttle at 3k rpm. Figured it was a lean condition due to vacuum leak so looked at the usual suspects, carb boots were leaking through a small crack, replaced. Pulled carbs and ordered a couple rebuild kits. Diaphragms are good but the left carb had a needle broken in the mixture screw hole. With some very gentle convincing was able to get the tip out (shh dont tell xschris lol). Up next were throttle shaft seals, basically crumbled as I pulled them out. Petcock was fine, I think its mechanical anyways. Gave the carbs another good clean and some things that I wanted to note and see what yall think, 145 main jet size and 42.5 pilot jet. Kinda makes sense seeing as how this thing runs pods with baffled exhaust, not sure but if someone wants to chime in I'd love to hear your thoughts. Carbs are still on bench so I have to do some more tuning once they are back on.
On to the next problem.
Kills batteries. Started with a new fresh battery and was left stranded at the convenience store so battery ain't charging. Haven't checked resistance at stator but rectifier checks out and regulator doesn't. When I was trouble shooting, at 2k rpm voltage at battery was reading 12.76 and falling slowly. The regulator was a cheap and easy fix to rule out before getting into stator, seems unlikely to me that a bike with low miles like this one would have a burned out stator but we shall see. Ive searched this forum extensively for this specific issue and it seems to boil down to those 3 components but I might be missing something. Found a used oem regulator on ebay so thats gonna be fun lol. I know there was a fellow here who had an extensive write up regarding regulators and aftermarket replacements so if this isn't the key I'll look closer at that thread. Thats all for now, if the weather permits I'll put everything back together this weekend and see what else catches fire lol. Thanks again for all the support and knowledge, this place is an invaluable resource for beginners and I can't be more grateful for it.
I used a TransPO brand C8313 Heavy Duty Adjustable regulator on mine and it's been working great. Pick up the pigtail for it as well for easy wiring it in.
I thought that was your write up tstidham. Here's the one I got off a seller on ebay. Claims it worked when taken off the bike but we will see. Cost 15 bucks so if it doesn't it isn't a total loss. If it ends up being busted I will go ahead and get the transpo. Wasnt able to put it all together today due to carb rebuild kit having wrong mix screw. When I pulled up the parts diagram to order an oem one I noticed that there was nothing about rubber seals and washers that I so commonly see on this site. I'll attach some photos of the stock and the new screw and if anyone has any insights I'd be grateful to hear them.


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Yeah that looks like the one I've got. Unfortunately I went through a local yamaha dealer and paid through the nose for two of them. Seemed to me that it would be the only way I could ensure that it was the right fit. Never used part zilla before are they pretty reputable as far as getting oem parts that fit?