Re-torqued head, bike won't fire.

[TeeCat]

Hi, guys -

Some of you may recall that, last weekend, I re-torqued my '73's head according to the recommended procedure/specs, but I didn't have an opportunity to fire it up until today. The bike won't fire, however. The voltmeter is showing a tad under 12 volts with the headlight on (comes on with ignition), which is always more than sufficient; this is a bike that fires on the first or second hot kick, like clockwork. Today... no sign of life. I put the battery on the tender just in case, and the tender went into maintenance mode almost immediately, so I'm pretty much ruling that out.

When I was taking off the upper engine mounts to access the acorns, however, I distinctly recall having "pinched" the gray-encased PAMCO wire (from the unit to the coil/ground) between my socket the the frame. I didn't cut the gray casing, but the edge of the socket put a little depression in it, and I recall being concerned that I may have crushed or cut one of the internal wires. I kind of dismissed that possibility, but find it curious that the bike will not fire now.

Some time ago, I prepared a test plug to check for spark without damaging the PAMCO or coil, but have not used it in a while, so I'll have to refresh my memory (I'm an electrical/electronics moron). The bike ran beautifully up until now and has no history of fuel delivery problems since the one-carb conversion last fall.

I was wondering if anyone has any ideas for a fairly definitive tests in addition to the spark test, which I'll have to perform when I get some time off. Also, do you agree that I could have crushed one of the small wires coming from the PAMCO, and if so, can that be fixed by me, or am I looking at another unit?

Thoughts welcome. Might go have a little chat with Captain Morgan in the meantime. I normally don't visit him during the week...

TC

Edit: Just remembered to look for this, so I suppose I'll try that first when I get time. Strongly suspect I screwed something up, cut/damaged something, or disconnected something.

 

[littlebill31]

I would test the Pamco as the link shows. Test for spark, but as you know, make sure the plug is grounded to a fin or something first. Also make sure you have 12volts going to the coil.
Kill switch ok? Ignition ok? Do you have a ground wire to the engine? Mine is on the top mount and comes off when I remove that mount. Supposedly the later models didn't really need them, but I remember someone telling me the early ones have to. Don't quote me on that, but I remember hearing it.
Double check that the float bowls are getting fuel as well.
Just trying to throw some ideas out there.

 

[TeeCat]

Bill, thanks. I'll try to get some time tomorrow to check for spark.

Kill switch and iggy have never been a problem. The grounds that I know of are to the frame right behind the tank, and to the lower rear engine mount, but I did not disturb those. The only wire I moved was an apparent ground on the top mount to the original condenser, which I'm not using now because of the PAMCO, but I reconnected the ground loop under the bolt anyway, just like I found it. The condenser is unplugged, though.

I have a hard time believing that I could have boogered a wire with the edge of a socket, but I effed something up, that's for sure. Might not be able to work on it til tomorrow or the weekend.

 

[xjwmx]

If you didn't cut the sheath it's not likely you broke a wire inside or its insulation.

 

[RFLIVES]

I vote for loose or disconnected coil wire. red/white / yellow wire going to the coil

 

[TeeCat]

I'll check those things as soon as I can get out there again, guys, thanks!

I have not yet checked for spark, but I did pull the plugs. They are both bone dry. I have kicked and cranked enough so that they should at least have some fuel on them, I'd think. So now I'm entertaining the thought that I might not have fuel to the chambers. Tomorrow I'll pull the fuel line at the carb feed and make sure fuel is flowing; I did just replace the plastic in-line filter with a one-piece Purolator, but the bike ran fine the one time I tested it. Maybe there is some weird air/restriction/vacuum thing going on.

Please confirm if you think the plugs should at least be damp; they are bone dry.

Thanks!

 

[RFLIVES]

Your over thinking it I'm sure check for voltage at the coil then check for spark. It's something silly I'm sure it always is.

 

[TeeCat]

I'll try to do that tomorrow, RF. I know how to check for spark, but how does one check for voltage at the coil?

I still think it's odd that those plugs are bone dry, though. I mean BONE dry. I let the bowl run dry the last time I ran the bike. When I worked on the head, I disconnected the fuel lines from the tank. Maybe there's air trapped in there or something. Will check that tomorrow.

 

[angus67]

um....uhhhh.......someones gotta ask.......did you turn the gas on?

 

[TeeCat]

Yup... I did. Still hoping there might be a vacuum in the line, since I ran the bowl dry last time, and then introduced air into the line when I removed the tank to work on the re-torque. I will know tomorrow, I suppose, but those plugs should have some fuel on them after kicking/cranking.

 

[littlebill31]

My Honda wouldn't fire up one day due to a vacuum problem. I unhooked the fuel line to remove the carbs to check them. As I was pulling off the fuel line from the petcock, carefully as it was full, it suddenly emptied into the bowl once it popped off of the petcock.

 

[TeeCat]

Yup, that's my theory, Bill. Tomorrow, I'll pull the line off at the carb inlet, open the petcocks to make sure fuel flows, and then reattach the line to the carb. I just think it's something odd and silly like that, because I didn't mess with anything in the ignition system, and especially since the plugs are utterly dry. Will advise.

Good to know, Bill... thanks.

 

[angus67]

sorrry... had to ask. thta would be the ultimate silly. I once waved at a passing rider, and accidentilly hit my kill switch. freaked me out. five minutes feels like forever pulled over in the fast lane with four feet between jersy barrier and cagers blowing by.

 

[xjwmx]

accidentilly hit my kill switch. freaked me out. five minutes feels like forever

The guy who taught me how to ride said that on one of his first long trips he went into a gas station and came back out and couldn't get the bike started. Some time later and preparing to call a buddy with a pickup he realized his kill switch, which he never used, had been flipped. Either he brushed against it accidently himself or somebody played a trick on him. To completely go off topic...

 

[5twins]

TC, you certainly know how to turn a simple task into a major operation, I'll give you that, lol. If I was your bike, I think I'd run away from home.

 

[TeeCat]

I've done that with my kill switch too, but not at speed, happily. I've sort of trained myself to give that switch a really wide berth!

twins... not sure my bike has ever thought about that, but my wife may have when I'm bitching about the bike!

 

[TeeCat]

Well, just very quickly before work, I checked and seem to have fuel flow to the carb. When I get a chance, I'll check for spark or lack thereof/some electrical issue. I'd think it has to have been something I did when I was doing the re-torque since I was working around those ignition wires.

 

[littlebill31]

Don't forget to check that one fuse you have.

 

[grizld1]

There's no "those" to the fuses on a TX650--just one main fuse. TC, you need to do the simple thing and see if you have spark. If you don't have spark or if it's weak you need to buy a multitester, fasten the neg. probe to a fin with an alligator clip, set the tester on the 20V range, turn on the key, and touch the positive probe to the positive primary terminal on the coil. Compare that to battery voltage. If you get nothing or a big drop in voltage, work back down the line until you find the grief.

 

[TeeCat]

There's no "those" to the fuses on a TX650--just one main fuse. TC, you need to do the simple thing and see if you have spark. If you don't have spark or if it's weak you need to buy a multitester, fasten the neg. probe to a fin with an alligator clip, set the tester on the 20V range, turn on the key, and touch the positive probe to the positive primary terminal on the coil. Compare that to battery voltage. If you get nothing or a big drop in voltage, work back down the line until you find the grief.

Yup, once I get home I'll indeed check the fuse (though I know from experience that when it blows I don't even get lights, etc.), but first I'll check for spark. Would have done that this morning when checking for fuel supply, but time was on short supply.

And griz, thank you for the specifics on the multitester. I do have one and shall follow that procedure. This misbehavior definitely correlates with the head re-torque; I have to believe that somehow I disturbed a connection, maybe shorted something (though don't recall being aware of any arcing, etc., while working). Hoping it's going to be something dumb I did inadvertently while pulling/reinstalling the tank or the top mounts.

(Incidentally, I am retiring in June and am considering maybe taking an introductory auto/motorcycle electronics course at the local CC or something. It's the one thing I really just don't "get", and that I am the most apprehensive about. I seem to do at least a little better on the mechanical side of things.)