XS400 sputtering after short run

Hey guys,

I got the Maxim XS back together, ready to take it down for an MVI, figured I'd better give it a short run to be sure all was well. So here we go , maiden voyage. Now up until now, my running has been on a CVT scoot, so after a few practice runs in the driveway to find the friction zone, which is pretty small, figured it out after a couple of stalls..... took a 2 block run to a nearby parking lot for some drills..... Running good, gonna take a bit to get comfy with the handling, but that's fine... get her up to 3rd....

Make it to the lot.... did a few circles, starts and stops.... hard to get a smooth throttle response and maintain a steady speed... head back home, get out of the drive and she starts to sputter.... tank was a bit under half (guessing) switch to reserve.... same thing.... uh-oh.... limped her home...
she stalled twice... felt like it wasn't getting gas..... but after letting it set and restarting, which took longer than normal, , I can see the fuel move through the filter, sprayed wd-40 looking for a vacuum leak, nothing showed up. Going to try some new plugs and see if that helps, any other ideas? Yet another carb cleaning coming up?

 

I'd guess you don't have a Fuel Problem ... I'd say you should shake-down an electrical proplem.

Do you still have a stock Fuse Panel ...
If so, replace it with a Modern one.

http://wirewerksperformance.com/index.p ... 87ee7829ba

 

Thanks to you guys on here I got that one taken care of, did the inline, weatherproof blade fuse replacement. Before I put it away tonight I started her up again, had some mis-firing firing on.... picked up some new plugs as they haven't been changed (overlooked that). Will see if that helps, plus I can get a new plug chop reading as well.

What else should I be on the lookout for electrical wise?

 

Alternator Brushes.
Starter Brushes.
Loose Bullet-type connections inside the Headlight Bucket.
Oxidation beneath Ground connections. (Main, Coils)
Dirty contacts. (Voltage Reg., TCI)

 

Cool, I'll give it a good going over tomorrow and see if I can find anything....
Thanks....

 

I forgot Turn Signal and Brake Light Bulb Sockets.

Spray 'em with Cleaner that dissolves the oxidation and evaporates quickly.

 

I've done the bulb sockets and the main ground already....
Need to check a few connections, coil grounds and get the stuck bolts loose to check the brushes on the generator

 

Get a Hand-held Impact Driver from SEARS.
Buy a 1/2 -to- 3/8th Impact Drive Converter.
Pick-up a Set of 3/8ths Drive Allen Sockets.

Worth they're weight in Diamonds when you have to loosen stuck Cap Screws all over the XJ-Bike.

 

Got an impact driver, the XS used Phillips heads, some of which are not in the best shape, plan to convert to Allen heads as I get the out.

 

OK, new plugs helped a lot, going to finish going over the main connections after some more coffee....
Managed to get 1 of the stuck generator screws out, only 2 to go.... (checked the rest of the bolts on that side as well, only a couple still stuck (was all but 1) I see a bing of replacements coming up soon)

Once I give everything the once over I'll give it another short run and see if I fare any better today....

 

Got another one loose, only 1 left, hit it again with some PB Blaster, may need to dremel a slot as a PO had the Phillips head looking like a Robertson.

On the connection side, I found the negative terminal of the battery wasn't tight, other than that nothing out of the ordinary found. Too beat to trust myself on a run right now, will check it out tomorrow. She's idling now without any stumbles at all (was horrible yesterday after the run)

 

That loose Battery connection is a big find!

You made a BIG Leap on that score!

 

Cool, will finish up and give it a test run later, if all goes well... MVI tomorrow

 

OK....
Went to try another test run tonight.... not good....

Rick, when you're right, you're right. I'm in electrical hell
The problems showed up when I re-assembled the headlight, including that horrid rats nest of wires. This time no sputtering, just a stall, is I tried starting in gear with the clutch lever pulled, nothing.... aha!! a safety switch..... after I pushed it home to check out which was shorting out (glad this bike only weighs 400 lbs) , was just beginning to get dark, I realize..no headlight either.... pull the seat, check the fuses..ok there.
open up the headlight bucket, once the wires start to move I hear relays click and the light comes on... lovely... then I realize my brake light is on.
And to top it off, my neutral light is now back on in all gears again (had that one fixed shortly after I started working on this thing)

So tomorrow after work I begin to dig into this mess, checking all the connections in the bucket as this seems to be the source of all evil.
2 questions...
1) Where should I start? Just pull all the connections apart and check them as I put them together...something is shorting....gotta track it/them down
2) What would be the best way to do this to avoid putting that mess in the bucket? Small plastic container, weatherproofed, with only the headlight wires and maybe a couple of others in there?

 

No.

It all gets tucked into the bucket.
Take your time and make a Project of it.

All those connections in there are "Quickies" just to make building the Bike take less time than if they were solidly spliced together.

You can snip-off any aged or "Lazy" M/F Bullet-style connections and join them securely ~> AFTER <~ you are certain about the wiring.
All the Grounds can go to a Common Ground.
Stuff like signal lights and anything with the Aged Bullet-type connections can be clipped, stripped and crimped.
(Soldered if you feel like a Pimp)

 

Heh,
It's going to be a project, alright....
I got a few ideas to try to make things neater..... to get it out of the way of the rear of the bulb, which is what most likely started the problem, old wire and heat are an bad combo at the best of times.

I'll post a follow up tomorrow night, if I get inspired with a good idea may include a pic or 2

Time to get the manual and meter ready for some extra work

 

ding ding, end of round 1

Found 2 of the issues, not even headlight bucket related......

1) brake light on..... hook for the switch had dropped out of the hole and attached to the bottom of the brake leaving it at tension all the time... re connected and adjusted switch height to prevent it happening again
2) neutral light, remembered it was like that when I got it, a PO had removed the Diode for the side stand switch and direct wired, I replaced the diode with one I had here, apparently too weak, it had burned out, must've been fine at idle, but once under load, it cacked.... could also be related to the sputtering if the safety was coming in and out while it was slowly failing.

Questions for Rick...
1)Do you know the specs of the diode Yamaha used for this purpose? Do the XJ's have them as well?
2) Is it safe to run with this disconnected? Just tape up both ends until I find a replacement. I like the feature for those brain fart moments, so I do plan to replace it.
(I know I cheated and snuck 2 questions under #1)

OK, time for a tall cold drink (it's freakin' hot out there today) and then back the the bucket to clean things up, and be sure there are no other issues...

 

OK update... this one is a headscratcher....

So I cured the brake light on thing, replaced the diode with a 1n4001, all's well there, neutral light back to normal......

Was still stalling if I put it into gear, figured a faulty clutch safety switch, ...
checked that, all seems well....
On the centerstand, I can start fine in neutral, I can shift through the gears without the clutch, if I pull the lever while in gear, stalls... if I feather it in some, it's fine, pull it in...stalls.... added bonus, taillight dims... even with the clutch switch disconnected.

ideas on this one? Oil pressure switch?

 

Bad Safety Relay.

Unhook the Safety Relay and the Bike should run.
<>DANGER<>

Without the Safety Relay the bike will Start in NEUTRAL and RUN.

Replacing the Safety Relay with a Standard Relay causes the Signals to the Safety Circuit to behave in a Dangerous Manner.

The START BUTTON will NOT engage the STARTER with the CLUTCH LEVER pulled.
The START BUTTON >>> WILL engage the Starter with the >>> CLUTCH LEVER RELEASED.

The Bike will NEED to be IN NEUTRAL to RE-Start.
>>> BUT
The Starter will engage and spin the engine with the Bike IN Gear and the CLUTCH LEVER RELEASED.

Use Caution.

 

I did try it without the relay, and got nothing, starter did not engage.
I'll see if I can locate a new or used relay. and I don't want to try messing around without the safety. Still too much of a rookie for that

Hope I can get all these gremlins out before the end of riding season ...
The brief ride I had with it working felt great...

 

OK, got a couple of lines in the water locally looking for a relay.
Luckily it's pretty common, was used in the XJ's, XV's and several others as well

Pulled mine yesterday, and did a bench test. Manual says the DC resistance should be 100 ohm, reading are all over the board... 44, 67, 75, 120,
When I connected the meter I'd get a reading , then 0 (is that normal for a relay?, never tested one before) and each time, a different resistance reading. so, yeah, it's toast.....

 

Well, I did a bit more testing.... bypassing the relay.... can get it up and into gear (on centerstand...safety first).... but it's laboring to stay running....
I I squeeze the clutch lever, the lights dim..... (headlight, meter lights and tail light).... now at this point there is no cutoff relay, I disconnected the clutch safety to be sure it didn't effect the test, so the only thing the lever is doing is engaging/disengaging the clutch... dimming occurs in mid pull, guessing roughly around the friction point....
What else could it be, is it some freaky connection (been double checking everything, but haven't found anything yet) or am I looking at a serious electrical problem here, TDI or ignition coils maybe?

Rick have you ever run across something like this?

 

Sometimes you'll get weird electrical anomalies when you have bad/broken grounds. Check to make sure your engine and chassis are properly grounded to the battery. The engine may be using the clutch cable as a ground path back to the battery or vise-versa.

 

Could be something like that....
Guess I need to figure how it's getting grounded with the clutch.....
The 2 main chassis grounds are fine....checked them first.....
What's bothering me is, why no problem until the lever is pulled?....
If something was shorting to the engine, that should be there always, as it's bolted to the chassis, not only with the lever pulled......

Hoping this sinus cold will clear up so I can think clearer and get something happening this week...it's getting cooler, would like to get this old girl on the road for a bit.....way behind schedule now....was almost there I thought.....

 

This is very weird.

I'd look to see how the wiring looks underneath the Coils where that Clutch Cable is running by.

When you get to where the Friction Point is ... you seem to be "Closing Something" to ground.

Either there is a Spark Plug wire that is wrapped around the Clutch Cable or the Wiring Harness is being pulled or pushed to a point where some solid connection is being pressured in some way.

Clean the Ground Contact for the Coils and sand a nice shining contact to the frame. Shoot for the "Path of Least Resistance." Then, route the Coil Ground wire so its NOT touching anything else but frame.

Make "Patches" of Old Inner-tube and Electrical Tape them to anything that might be suspected of shorting to the frame of some other wiring harness area.

Be sure that the MAIN GROUND WIRE is tight after sanding the Eyelet and its connection point.

Be sure the Battery Connections are Clean and Solidly tightened.

Look at the two "Rings" on the Alternator for Out of Round tracking by the Brushes. Glass Paper or Pencil Eraser the Twin Rings to remove anyplace where they are burned from arcing.

You might find out after all the testing is done ... that you are (or were) low on fluid level inn the Battery and some Battery Cells are near done for.

Do a test of throwing-out the Clutch with a Wrench on the Throw-Out Arm instead of Pulling the Lever.

What happens?

 

The coils are hidden under the frame, the clutch cable is routed between the frame and tank, doesn't come in contact with anything else....excect maype a plug wire...I'll check that tomorrow..... great thought....

Getting at the coils will be a small nightmare, but worth it if that is the problem.

Still fighting with a final screw to get at the generator to check brushes, the screw head is fubared and will need alternate persuasion to come off... but I know it needs to be done, will need to locate some proper sized replacements first.

The battery was just purchased this summer, hopefully not toast already.

NOt sure how to do the throw out arm test, will need to do a bit of research there

An after thought, is it possible that the clutch is sticking at the friction ponit enough to drop the rpm's resulting in the dimming & stalling, yet be fine when fully in contact? A physical possibility instead of electrical?

Thanks again for the ideas... you keep me thinking

 

A little bit accomplished so far today.... sinus cold is slowing me down...

Checked the clutch cable, not touching the plug wire or any other part of the electrical system, it is, routed improperly though, so I'll need to correct that while I'm at it.
Battery.... 1 cell is lower on fluid than the others, but still between the mni/max lines, plan to top up the cells that are lower than the others.
Also picked up a battery hydrometer so I can check each cells SG level, will need to fab up a tip extension as it's just a bit too big to reach the fluid.

Hoping to feel better tomorrow, then I'll pull the tank and go over the whole harness (at least what I can get at) and see what's what, and try to get at the coils, clean up the connections and do a test on the meter while I'm at it.

I'l get into the generator as well, need to pick up those replacement screws!!!!

 

Sinus has now moved into the chest, breathing sucks but at least I can think clearly....

After thinking on what I changed (best best to look if issues arise) I replaced the 1n4001 with a 6amp rectifier diode.... basically the same results......

so while checking wires and such, I disconnected the clutch cable from the handle and then checked...again the same....reconnected the cable, properly routed, and now everything seems to be working..... Will keep checking while i get the rest of the work done, no more test rides until I get the new relay and charge system up to par (read below)

Now that makes no sense to me at all....but ...as long as it's working, thinking maybe clutch cable was allowing a strange leak to ground from part of the harness (noticed while moving the cable the harness for the horn, signals, headlight was touching)

Now I know I need a new relay, still looking for one, may have to order from the stealership....but have a few leads to check out first.

The charging system is also beyond suspect.... got her revving at 2000 rpm, put a meter on the battery and it's only reading 11.85v battery was reading 12.87 (unloaded) before I hooked it up...... revving higher still resulted in no change, so I'm not generating any recharge at all

Grabbed some hopeful replacement bolts for the generator cover but came up a hair short.... was the longest at the hardware store.... will have to go elsewhere now....

So mr dremel and I got friendly with the last stuck bolt,made a larger slot across, but still not loosening, hit it with more pb blaster will try again tomorrow.. gotta get inside there to see what's happening with the brushes.

 

I hope you find the Brushes are the root cause of the no charge.

I use my SEARS Hand Impact Tool on the stuck Cap Screws.

The Sears Tool > 1/2-to-3/8 converter > Allen Socket >

Pre-torque > Whack = Loosened ~> Done!

 

DOH, my screws "were" phillips heads.... the remaining stuck one was stripped by a PO beyond round.... I will have it out....
Once I get that cover off I'll give it a good going over, measure the brushes and clen the rings up .

If not the brushes, where should I look next, rectifier & regulator?


Cool... just checked the parts list on cmsnl.com (same as Yamaha and bike bandit only they also list what other models used the same part)
The brushes are the same as the XJ's & rectifier/regulator are the same ones used on the XJ 650, 700, 750 & 900's
Should be able to find at least...

At least I feel close to resolving the issue.....

 

Common Parts.
Used by Yammie on dozens of bikes.

 

Ahhhhhhhhhh

Rick, you'll be prod of me today

Found a loose ground!!!, tightened and ALL dimming disappeared (yesterday it was running, but some minimal dimming of the lights)

AND....

Bolt 3 on the generator is off!!!
Brushes measured in between 10 & 11mm, cleaned the rings as instructed as well... still no charge to the battery... new brushes needed?
It was filthy in there as well, lots of fine carbon powder from the brushes

So overall, things are looking good except for the charging system, will do a quick test run tomorrow, if it passes that, I should be able to get it to pass the MVI and at least that will be done, will order some new brushes and see if that fixes the charging issue.

Hmmmm reread the brush length info I can still see the wear line and they are above the minimum...... regulator/rectifier next thing to check

Thanks for all the help and walking me through this,....
If you're ever up this way, I owe you a beer, or few

 

Bad grounds will get you every time!

 

Yep....they've been the bane of my existance, from bikes to music gear

 

The Question then becomes:

"Is Rick the Kind of Guy who would ride 685 Miles for a Beer?"

I've never been to Nova Scotia.
I got the bike.
I got the gear.
I got the time coming.
My annual "Long Haul" got postponed.

How much is a "Round-trip" on the Ferry???

I'm dreaming.

 

I can check on the ferry prices for ya later

Maybe next year, during the good weather , I'm sure we can talk Woot into a cruise as well He doesn't live far from me....

 

A bad ground can kill a voltage regulator, hope it didn't get your's but from the sound of it I doubt it made it through unscathed. Had the same flickering issues with my truck last month, internal failure but the symptoms were similar.

 

I think it may have, I still have no charge happening.....
checked the remaining wiring for breaks or wear for that matter....
I thinking the regulator/rectifier unit will need to be replaced.

 

WOOHOO!!!, finally got in a test run (quickie down to the school parking lot, a few loops and back) NO issues (other than me needing more clutch/throttle practice.... wow, CVT on the scoot has me a bit spoiled...must get a lot of practice in now that it's working)

 

Was the regulator fried?

 

Apparently not ... looks like he's still in the "Zoom Mode!"

 

Not fried, but not full functional it seems, everything works great, except there is still no charge going to the battery...... keeping my eye out for one.

 

If you don't have a charging output from the regulator, it is junk. A no charge condition indicates it did get fried. What is the year and model of your bike again? I didn't see it in your signature line. I've got one from a 650 Maxim as well as an 80 XS 750 that I could let go for coin if needs be.

 

Thanks for the offer....

It's an 83 XS400 Maxim,

Reg is OEM# 12R81960A1

http://www.cmsnl.com/products/rectifier ... 2r81960a1/
If you check the link it'll show what other bikes used it.
(that's why I like cmsnl.com, great for cross referencing)
The one from the 650 Maxim should be the same...
here's a great pic of it,
http://cgi.ebay.ca/1983-Yamaha-XS400K-M ... otohosting

gotta call the local used parts shop to see if they have one as well, just in case they're different.

Better tag that into my sig line as well

 

I have an 82 maxim as a parts bike. Send me a pm if you are stuck.

 

Sweet, thanks olebiker.

I got a reply from the local shop on the reg, $75, seems a bit high.....