bad battery?

oh yeah, i was thinking about fuel level in the bowl and it seems to me that based on the way the float is hinged, the fuel level at the front of the bowl would be the same whether the carbs were level or if they were on the bike tilted forward, right?

 

good news (sorta): i ohmed out both coils and confirmed that i still get open loop between 1 and 4, and i get 21 k-ohms between 2 and 3, so new coils are definitely in order (here's to hoping that solves my problem).

i also checked the float heights, on the bike, on 1 and 4 (i don't know how anyone can do it on 2 and 3 without taking the rack off. . .) and, if this description is clear enough, the fuel comes up to the lip on the bottom of the carb body on the front of the carb - which, i believe, is spot on.

a little perplexing, though, is that on both carbs i had some air bubbles and i had to bend the tube around a little bit to clear them before the fuel would rise to the lip.

maybe this isn't an issue, but now i'm wondering if there's something keeping my bowls from filling completely.

i'm assuming the bowls have to vent to atmosphere somewhere in order to allow them to fill properly, most carbs i've dealt with have an overflow tube connected to the bowl drain that accomplishes this, but these hitachi's don't have that system, so - do these carbs vent to atmosphere and if so, how? is that what the jets on the air box side of the bore are for? is it possible that these are clogged and are causing my bowls to not fill properly?

course the real conundrum is that these carb worries seem, to me, to point to a lean condition, but when i look at my spark plugs, they are wet? ? ?

 

Yes, those are the bowl vents (in the carb throat, facing the airbox).

Yes, they could get clogged, but it's highly unlikely, as those are huge vents!

 

what's on the other side of those jets - i.e. if i shot compressed air into them, i'm assuming i should get air blowing out somewhere in the bowl side of the carb, but where should i expect it to come out of? i looked at the drawing from the haynes manual, and it doesn't show the pathway for those jets . . .

 

Those jets lead directly into the bowls..........

 

Skeeter, your problem sounds like what I was having on my xj900. It would crank fine but wouldn't start. It then smelled gassy. I would then try to compression start it and if that worked I was good to go but having to feather the throttle until it was running strong. When I came to a stop I would have to baby the idle to keep it running. At work one day it did the same crank but not start, but I this time I couldn't get it to compression start so I found a service truck with jumper cables and jumped it. It start right away and cranked a lot faster than it was on it's own. I ended up replacing plugs, that looked good, and a new battery. I think my problem was the battery. I think the cranking amps of the battery, although enough to crank the engine over, was not enough to the coils to produce a hot enough spark to ignite the cylinder fuel. I have no starting problems now nor any idleling problems.

 

once i put new plugs in, it starts very easily. i'm hoping the replacement coils straighten the problem out, if not, i'm going to double check my battery and charging system.

sounds like we have similar symptoms with a weak spark situation, but i think while your issue was battery related, i'm thinking mine is coil related.

 

new coils arrived yesterday and they ohmed out good so i put 'em on. i could definitely see a stronger spark and the bike seems to run marginally better, but i don't think that was my problem, as it doesn't want to idle without choke (unless i'm just not letting it warm up enough - it's too cold to open the garage door and i don't like breathing all those fumes, so i haven't let it idle for very long. - i think i'm gonna wait for warmer weather.

in the meantime - i'm thinking about replacing the throttle shaft seals, is there a walk through on breaking apart the carb rack? i can't seem to find one. i'm assuming you just need to unscrew from the rack and you also need to take the butterflies off the shaft?

 

Yes we have walk-throughs. Please refer to the following links, both located in the FAQ section.
Rick-O-Matic's complete DITY http://www.xjbikes.com/Forums/viewtopic/t=2908.html

Gamuru's http://www.xjbikes.com/Forums/viewtopic/t=8918.html

Good luck!

 

thanks for the links robert, but they don't address my question "do you need to remove the butterflies to replace the throttle shaft seals"

fortunately, i took my carbs off to clean them again last night and i was looking at the rack and it appears you do not need to remove the butterflies. so i anwered that question myself, i think.

i also found a bunch of black crud dotted all around the inside of my bowls. i had been running sea foam in the gas, and i think the mixture was too strong sea foam and it was eating the float bowl gasket. i cleaned that up, blew through every passageway (i'm glad i at least know them all so well now that i don't even have to think about what goes where) and it STILL wouldn't start.

then i realized i forgot to connect the choke cable. once i gave it a little choke, it fired right up and i was able to get it to idle with no choke. time will tell if this is an actual fix.

the bad news is that while it was idling i checked the voltage on the battery and, even if i rev the bike up to 4k or so, it stays at 11.5V (grumble)

oh, and i also discovered an exhaust leak, right in the "crotch" of where all 4 pipes come together. think i can jb weld that or something?

edited: i meant to say "bad" news, but for some reason i typed "good" news. but i did find some good news - looks like permatex makes some exhaust repair stuff that should work.

 

Glad you found your main issue, I'm sorry if I didn't address all of your questions. You do not need to remove the butterflies to replace the seals but it sure makes the job easier.
As for your 11.5v reading, what does that same meter say when you measure a new 9v battery? I've seen a few instances where a meter reads incorrectly and gives a false impression of the circuit under test. Make sure you are reading with a good meter. If you still have low voltage after this, you really need to check your alternator brushes first. low/bad brushes will burn out batteries and cause a host of other little nasties so I'd check them sooner rather than later.
JB is good for some things and this may be one of them. It all depends upon surface prep, cleanliness and temperature. Lower on the exhaust means lower temps so you may be ok. Given that you cannot get a good seal inside of the leak, your fix may only give a short reprieve before it comes back so plan on a more permanent fix.
Best of luck!

 

thanks for responding, robert.

that's a good tip about the voltmeter possibly being inaccurate - i'll double check it with my older analog one.

i already checked my brushes and i believe they have lots of life left. there was a mark on the brush (kinda looked like someone pressed their thumbnail into it really hard) and not quite a 1/2" of brush beyond that. i was under the impression that the line is the wear mark and as long as you've got *something* past the mark, you should be ok.

i've got a feeling they've been replaced by a previous owner because the alternator cover screws were allen head screws and not the "screws that look like philips head screws but aren't" that RickOMatic mentioned in his "check thine brushes" post.

however, i am wondering if i messed something up when i checked in there - the cover kinda fought me going back on - it didn't seem to want to line up quite right. i chalked it up to all the magnetic stuff in there pushing me around so to speak. think there's something wrong in there?

assuming the meter is correct, it is definitely a charging issue and not the battery, right? i'm assuming that even if a had a bad battery, the voltage would read whatever the bike is supplying regardless of what kind of shape the battery is in?

also, would it be a safe bet that if there's low voltage across the battery and the brushes are ok, it's most likely a)a bad ground or b)a bad voltage regulator?

 

The line on the brushes is the limit line. If you have plenty of brush past them, you should be in good shape.
Replacing the cover can be a dicey affair, I can't say it is one of my favorite things to do either. I've fought the same fight as you so I know exactly what you are referring to. You do need to be sure that you slip it on square. It can, and sometimes does, slip on cockeyed so be wary. You are fighting the brush tension and the stator ring. It helps to have some idea of the alignment of the cover before you try to juggle all the parts into place. By this I mean ensuring that the stator is properly pressed into place at the right alignment (it is loose and will shift if you aren't on the ball). The other players in this act are the alternator wires and the seal that they pass through. That seal is hard as a rock by now and it doesn't like to flex very much so this can be a problem too. I recall juggling the seal, one screw, the stator and an allen wrench while trying to line it all up. Man I just don't like fussing with that cover.
As for the voltage, if the voltage is low and you don't see any voltage increase at 4-5Krpm, you do have a charging issue. This does not mean that the battery is safe/good but it can be a good indication as to why it may not be happy anymore. Do you have a maintenance manual yet? If not, you NEED one. It is the best tool you will ever own for your bike. The Haynes has a section on how to test your alternator and so on. I've the factory manual for your bike (available on the XJCD, well worth $10) should you need further assistance.
You can have the battery load tested to determine if it is sound or not.
Most likely is a grounding issue but a bad voltage regulator isn't out of the question. Go through the bike and clean all of the ground connections (back of the engine case, next to the coils, near the voltage regulator, etc...) and see if that buys you anything. It's free and will eliminate one more item on your to-do list.
Good luck!

 

well, i was feeling a little inspired after work this morning, so i decided to take a look-see.

i did a bunch of voltage checks on the battery and they were as follows:

on the battery tender: 13.42V
off the battery tender: 13.36V
ignition on: 11.57V
cranking the engine: 9.2V
running at idle: 11.49V (running with choke at ~1400RPM)
rev'ed up: 11.57V (assuming the tach is accurate, ~4000 RPM)

i also checked battery grounding as follows:
from the battery negative terminal to . . .
. . . brake pedal: 0.4 ohms
. . . ground wire on ignition coil: 0 ohms
. . . bare* spot on valve cover screw: 0 ohms


* the previous owner painted the engine black, but much of the paint is coming off, so i found a "bare" spot on the screw if ya catch my drift.

i know i checked the charging system out last summer, but unfortunately i didn't take any notes and i was hoping i posted something about it here, but can't find that either. i *can* tell you i took several 200+ mile trips without the battery dying and giving me problems.

do these numbers look alright?

did i bugger something up with the alternator cover?

did something go to sh*t on me?

any input is appreciated.

 

Good check on the ground system, that should let you breath a little easier. You still need to check the resistance to the ground wire on the voltage regulator. I am a bit concerned about your alternator output. I don't see how you can damage anything installing the alternator cover but it sounds like you do have a voltage regulator that is bad. They pop up on flea-bay regularly so a replacement shouldn't be a problem to find cheap. Source one and see what that changes. If no change, your charging system would be the next step given your alternator brushes check out. Oh, and I wouldn't take the bike out for more than a few miles ride until you get this sorted out.

 

can you be a little more specific here? i'm guessing my voltage regulator is the thing on the left side of the bike with a big heat sink on it, right? resistance between where, exactly, should i check?

thanks

 

The black (B) wire is the ground. Yes, the regulator (2) has heatsink fins.

 

Thanks for the backup Markie! A picture is worth a thousand words.
If the regulator isn't seeing the same ground potential as the rest of the system (or various parts), it could well think that it is correctly regulating when in fact it isn't. You have to ensure everything sees the same ground potential so everybody plays nice together in the sandbox. Incidentally, I've a few spare regulators in my parts bin should you require one.

 

much obliged. i'll check it out in the next day or two.

 

Unplug and inspect the contacts in both sides of the big connector off the regulator; a common point of failure.

Another issue that has cropped up occasionally with alternators is the internal corrosion of the tiny braided wires coming off the brushes themselves. The brushes may have plenty of wear left, but if their little lead wires are all green inside they won't carry much current.

I think you need to pop the alternator cover off and do a careful inspection.