1977 D no start

Petew

Petew

XS400 True Believer
Top Contributor
Messages
649
Reaction score
134
Points
43
Location
Johnson City, NY
Well, today I tackled my first set of points, the old ones would not open ,they were so worn. I was hoping the bike would start...but it did not. While cranking the bike on the starter it seemed to only be puffing on one side. I put my hand over the right exhaust and felt nothing. I'm guessing a yank and tear down is in order. Does anyone feel a valve adjustment first would prove beneficial at all? I haven't been able to get a decent compression reading, on this or any of my bikes, always the same gets to 90 and stops. Crappy gauge from Harbor Freight. Ideas anyone? This is also the bike with the weird noise when cranking over.
 
Also, I have noticed when rotating the crankshaft bolt anti-clockwise that I rotate the bolt around almost all the way and the tension releases and the bolt turns the rest of the rotation itself with noresistance, instead it feel as it is the weight of the crank pulling it around. I don't remember this ever happening on my others. This makes me suspect a drive chain, or pulley, or tensioner has failed. Am I thinking correctly or do all of them do it and I just don't remember.
 
Sorry i havent gotten around to posting the points video yet... Ive been having trouble with my Go Pro and the only computer i have uses a really old version of Windows that doesnt have any software support on top of my PC lacking a real video card..

I will get a video up but id like to wait until my next oil change.. i have maybe 800 miles to go so it might take about 3 weeks.

Did you set the points gap and static time them? Are you getting gas to both cylinders?

For whatever reason, my bike starts much easier when i kick it over. Its easy enough to take the caps off the head and verify that the lifters are opening the valves. Turn the crank bolt and watch for it.
 
I set the gap and static timed with a light bulb harness. I am not sure if both cylinders are getting gas, I can squirt some into the cylinders and see if that starts it. I planned on doing valve adjust this afternoon. I am doing starter clutch/ starter motor on another bike right now, hopefully we will get to both of them.
 
As a follow up, my 80G does not act the same when I rotate the crank, I will check how it acts after I adjust the valves but....
I am pretty sure an engine R&R happening....always need a project!
 
Make sure your clutch cable isn't over tight/out of adjustment. It will give a no compression feel to the motor.
 
If the clutch cable is too tight at the handle bars or at the motor the motor it will not turn from the kick start. Same as if you pulled the handle in. You kick start the bike with the motor in neutral not with the clutch pulled in. There maybe other things going on also but usually not.
 
Can anyone tell me if the solid state voltage regulator from the 79-81 bikes be used as a replacement for the mechanical regulator from a 1977 400D?
 
NewHavenMike said:
I bought a oem electronic reg to replace my mechanical one. I admit, Im not the best with motorcycle electronics, but I couldn't get it to work. I ended up buying a brand new one from an auto parts store that has been working perfectly and was only around $30.

Heres the one I bought:https://shop.advanceautoparts.com/p/bwd-voltage-regulator-r292/5430518-P
Click to expand...
Mike was the replacement a plug and go, or did it require fitment mods? Because I have not been able to secure a decent 77 tank I opted to go with a 1980 Tank, which moves the tank back and above the battery, making it a hazard to the battery case. I have crafted a mount to secure the tank but it is still very close to the battery case. I am looking for space savings and clearance, something a bit smaller but fully functional. I am considering lead iron batteries , which are shorter,but most recommend charging system upgrades.
 
Last edited:
To use an electronic regulator you would have to slightly rewire the field coil.
The field coils on bikes with mechanical regulators have a wire to the regulator and ground.
On bikes with electronic regulators the field coil goes to the regulator and a positive supply after the ignition switch.
 
That regulator I linked is not a plug and play deal. But wiring it is very simple and I ended up using the original harness too.

The new regulator has 4 wire leads, where as the original mechanical has 3 leads.

So from the new regulator, you connect green to green, black to black. Then theres the orange and yellow wire that you will splice together and connect it to the remaining wire from the harness. that will give you your 3 connections so you can use the factory harness.

Before I picked up this regulator, I cam across a website, Regulatorrectifier.com. They had a combo unit that was a "plug and play" deal for XS360s with mechanical regulators. Well I installed it and a few minutes later I had a dead battery.. Not sure if it was a faulty unit or the wiring wasn't proper but it was a waste of $100.
 
BBS360 said:
To use an electronic regulator you would have to slightly rewire the field coil.
The field coils on bikes with mechanical regulators have a wire to the regulator and ground.
On bikes with electronic regulators the field coil goes to the regulator and a positive supply after the ignition switch.
So, how would you recommend I rewire? Is there a thread that relates or could you explain to me what to do. Or, am I chasing my tail and will the 1977 charging system be okay for the AGM or Lead Iron batteries? I would be pleased if it would.
Click to expand...
Perfect! Thanks so much for your input Mike this may be the solution I can use. I will keep the other around as I feel it is still good and I can return things back to stock if I want.
 

Similar threads

T
77 xs400 starting problems
2
Replies
39
Views
1K
thecurryman
T
S
Need help with 1977 XS400 Carbs
Replies
3
Views
540
gpounce32768
G
C
Bike wont rev
Replies
6
Views
643
Crau
C
E
78 XS 400 2E won't start!
Replies
6
Views
460
Ed Dunham
E
Pmcbee
My xs400 adventure begins!!!
Replies
1
Views
190
CaptChrome
CaptChrome
Back
Top