Very low on power

Started by tig5, June 17, 2013, 02:10:15 AM

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pinholenz

Generally the Rev limiter wire can be cut as a matter of course to prevent problems of it malfunctioning. Its the black and yellow wire coming out of the TCI unit. It is related to the tacho rather than the speedo and when it is operating prevents the engine from screaming its head off in the case of say, an accident where  the throttle has jammed open. The rev limiter cuts the spark to one cylinder in an effort  to reduce engine damage. Most XZ riders just chop it off and tape up the wire to make sure that it doesn't affect their engine performance.
Only one '82.5  eXtreme Zen 550

tig5

2 steps forward, 1 step back.

I charged my battery and put the multimeter to it, 13.0 volts. Before I reconnected it I gave the terminals and the battery leads a good brush with a file and that seemed to solve the electrical problem.

I fired the bike up and it started screaming on both cylinders. I wiggled some wires and realized the HT lead that plugs in to the spark plug cap was loose. Problem solved.

However as it was running along nicely I noticed some smoke from down below and found some oil leaking from the LH engine cover where the starter clutch is accessed. It was dripping on to the hot exhaust headers. After I'd inspected my starter clutch I'd used liquid gasket sealer as the old gasket was toast. Is this an acceptable method or do I need to be using a proper gasket in here?

Anyway, I figured I'd check to see if the hex bolts holding the engine cover were tight and I ended up ripping the engine threads out of one of the bolt holes. Gutted. Im completely inexperienced with helicoil but I'm assuming this is the direction I need to go. Is it reasonably DIY or would I be better off just getting a shop to do it?

Churs.

Rikugun

Sorry to hear about the stripped bolt hole. Don't feel bad, you're not the first. Not everyone has a natural sense of torque.  ;) That comes with experience which by your own admission you lack. Personally I'd don't think the helicoil project is one you should attempt. Get a professional to do it.

To your other question - yes, I'd advise using a gasket on the cover.  :) Tiger may still sell these and they are still available commercially if I'm not mistaken.
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

pinholenz

Glad to hear that you are not so low on power now! But....

The Stator side covers are still available in New Zealand. I got one about a year ago from a now defunct Yamaha dealer on the North Shore. I would try Maidstone Yamaha in Upper Hutt first. He seems to be your nearest dealer and should be able to get it in.  http://www.maidstoneyamaha.com/

Good luck with the helicoil job. Damn...
Only one '82.5  eXtreme Zen 550

The Prophet of Doom

About $20 for the gasket from Yamaha but you still need to seal off the stator wires I've found.

If you have a stripped screw, it will be the crankcase that needs repair, not the cover right?
I've had no joy with helicoils, and you would only really use them if you need to retain the same bolt size like a spark plug.  They are installed by re-tapping at a larger size, then inserting the coil so you may just be able to tap out to the next size and get a bigger bolt.  It would depend on which one.  Tapping is DIY, but would advise some practice first.

Alternatively brazing the hole full with something like Ideal720 HTS2000 and re-drill re-tapp.  , or welding, though I'd avoid that due to warpage. This takes a bit of experience






Tiger

Quote from: Rikugun on June 26, 2013, 07:39:20 AM
Tiger may still sell these...

Yes, I still do, thank you... 8) $10.00 U S D + actual postage.

Re the stripped screw...They should be Allen head socket head screws, not hex head!!

There are several different lengths of screws used to hold the left side engine cover in place...all M6 - (1.0 thread pitch)...from the screw next to (right of) the oil filler hole M6 x 55 and going right (clock wise) M6 x 40 (this one should have a copper washer on it), M6 x 25, M6 x 25, M6 x 25, M6 x 35, M6 x 35, M6 x 35, M6 x 25 and M6 x 25.

LEFT SIDE COVER SCREWS 101 8)...Make a sketch of the left side cover on some cardboard and punch holes were the screws go, then mark the screw sizes beside each hole...you can then insert each screw in to the corresponding hole in your template...which means that you can put the right size screw back in the right hole...(I made mine out of 1/4" white plastic with a gasket traced on and screw sizes marked accordingly in black marker pen)... I also tell you this for another reason ;) You may find that you can insert another longer screw in to the hole that is stripped and pick up on a couple of threads that are still good before you try some kind of repair...or...run an M6 - 1.0 bottoming tap (flat end, not pointed) in to the hole and cut a couple of new threads to catch on to... :-\  ;)

just my 2 cents worth... ;D

                            8) ....... TIGER .......  8)
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well-preserved body, but rather to skid in sideways, body thoroughly used up, totally worn out and screaming HOOOOYA lets go again baby !!!!!!

'82 Vision, Pearl Orange finish, lots of up-grades!!!

tig5

I thought Allen was the Euro term and Hex was the more American way of saying it? Wikipedia agrees they are both the same thing, and also suggests they can be called Unbrako  or Inbus keys...but thats neither here nor there.

I like your idea of trying a longer bolt Tiger. The thread I stripped was the furtherest one to the right from memory, the one closest to the gear shifter. I do my breaking and home and my interneting at work at the moment so I can't confirm what size it is. Could be worth a shot though.

I'll try my local Yamaha guys for a gasket first but it's nice to know there are some floating around.

While I'm here....I've never noticed my fan spinning, but then again I've never been on a ride thats lasted more than about 10 minutes. Should the fan be running often? I'm assuming I can disconnect the fan at it's main harness point and jump my battery to it to check it's working? I have removed my temperature gauge for now but I understand the fan runs off the thermostat which is located on RHS of the engine somewhere?

Tiger

Just to clarify...Wikipedia is wrong!!!

Allen Socket head cap screws...you insert an Allen key in to the head to loosen/tighten...normally 12.9 grade.

Hex head cap screws... you use a wrench/spanner, socket, etc to loosen/tighten...Normally 8.8 or 10.9 grade

They are two different animals, believe me, I sell hardware (amongst other things) to industry, transport, automotive, motorcycle shops, etc, for a living... ;)

The fan is fused...the fuse holder/fuse (10 amp) is in the headlight bucket. Worth checking.

Remove the gas tank and you will see were the fan and electrical hook up is...you can then check to see if it works... 8)

                      8) ....... TIGER .......  8)
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well-preserved body, but rather to skid in sideways, body thoroughly used up, totally worn out and screaming HOOOOYA lets go again baby !!!!!!

'82 Vision, Pearl Orange finish, lots of up-grades!!!

Rikugun

Tiger makes a very good point about the importance of correct fastener length on this cover or any other assembly for that matter. As a general rule of thumb there is often a visual cue built it. When all the screws are inserted but not yet tightened, they will all have the same reveal. This tells you they are all where they belong. If one screw head seems closer to the case and another is further away than the others, swap them and and it will be right. This example is simplistic of course and in some cases there are 3 or 4 different length screws requiring more juggling around until they all have the same reveal but you can see the concept.  :) Using a template to ensure they go in the way they came out is good assuming the last person who installed the cover put the screws in where they belong.  :o  ;)

The take away here should be the correct length and torque, not which strength/style fastener is used or what they are called. The lowly Phillips head screw can be used and still achieve the very low torque requirement for this application.  Hex head cap screws were probably used as they aren't prone to stripping the head as readily as a Phillips screw. It may have also have been a marketing decision as much as anything else.  ;)
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

tig5

Haha i see. Does that mean I can loosen my Allen bolts with an appropriately sized Hex bolt?

tig5

When the bolt came out it had about 7mm of thread with it so I do think it was probably a bit short. I'll blame the PO, mine went back in the way they came out  :D

QBS

Rik, thanks for passing on the excellent tip regarding the achievement of similar reveals, so as to determine what goes where.  You didn't say it, but I'm sure you meant that this tip should be employed without the unthreaded piece of the assembly in place.

As an aside, many years ago when I replaced my first stator, I used the procedure outlined in the Haynes manual and traced a template for the engine cover attachment screw locations on a thin sheet of cardboard.  I used the new engine cover gasket that I had bought for the repair as the guide.  The factory gasket turned out to be in such good shape that I have never used the replacement I bought and still have it and the template I made to this day.

I wouldn't hesitate to use a carefully made home produced card board gasket in this location.

Rikugun

#32
Quote from: QBS on June 27, 2013, 06:16:19 PM
You didn't say it, but I'm sure you meant that this tip should be employed without the unthreaded piece of the assembly in place.
If you mean put the cover on the bench and start dropping screws into holes to check reveal then no, that's not a good idea. It's not always the features of the cover alone that dictate screw length. Holes with locating dowels often take a longer screw. Since they don't engage til further into the hole, their installed reveal is still the same as the shorter neighboring screws.  Examine all the screws and holes prior to assembly and pay attention to the clues.

Lay the screws out, install the gasket and cover as you normally would then insert the screws based on your visual inspection. With rare exceptions, all the screws should have the same reveal prior to tightening.  Usually you'll get it right the first go round especially after having done this kind of work for a while.

If it's a brand new engine or one that's known not to have been apart, take the time to make a template if you wish. Even so, come assembly time it makes sense to check your work and template accuracy with a quick visual inspection prior to tightening them. If a screw seems long, probe the hole with a dental pick and mark the length with your thumb nail. Compare the hole depth to the screw. If on the other hand a screw head is nearly touching the case before you've tightened it, it may be too short leaving inadequate thread engagement to carry the required torque load without stripping the aluminum engine case threads.  It's no real trick but rather taking your time and using common sense.  :)
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

tig5

Unfortunately the bolt was the correct length, I'll need to get it retapped. Also...

I'm back to one cylinder again  >:(

Tightening the HT lead to the plug cap was not what corrected the issue and unfortunately the problem is back. I can rule out cap, lead and coil. I swapped the questionable coil into the place of the functioning one and got sparks. No sparks at all when it is plugged into its original connector.

My bike is completely without instrumentation so the yellow/black cutout wire shouldn't be the problem.
Can anyone think of ways to track down the issue. It seems like a loose connection somewhere. I have a multimeter but I'm not very experienced with it.

Cheers

Re-Vision

Not sure I'm following you correctly, I can see where you've proved the coil is functioning on the good cylinder but it appears that you could still have a poor connection between the coils' HT lead and cap. Rather than testing possible bad components on a known good circuit, try replacing possible bad components with parts from the working cylinder (coil,HT lead,cap, and spark plug).

Quote
"Tightening the HT lead to the plug cap was not what corrected the issue and unfortunately the problem is back. I can rule out cap, lead and coil. I swapped the questionable coil into the place of the functioning one and got sparks. No sparks at all when it is plugged into its original connector." Unquote

BDC

tig5

Sorry, to clear up any confusion : I pulled the suspect coil with the lead and cap in place and connected it to the
other electrical connecter that the other coil was plugged in to. I then tested it with a spare plug grounded on to the engine cylinder. When the coil/lead/cap is connected to the front cylinder electrical connection I can get a spark. When the coil/lead/cap is connected to its original connection (rear cylinder) I get no spark. To me this suggests a problem further down the line.

pinholenz

I have had a situation where the plug seems to fire OK when not under compression and then fails to fire in the cylinder. They are a pain to get at, but have you swapped/replaced the plugs? (My offer of a set of Iridium plugs still stands). Cheers
Only one '82.5  eXtreme Zen 550

Rikugun

#37
Although not usually a problem on these bikes, it may be a bad pick-up coil aka trigger coil. There is one for the front and one for the rear cylinder connected to a bracket that resides within the alternator cover. There may be some diagnostic tests outlined in the manual. I wouldn't rule out damaged wires or connections  between the triggers and the ignition module either. There may be a rubbed/chafed wire under the engine cover if those wires weren't routed carefully during a stator swap.

EDIT: I'm unclear as to which cylinder is affected by the rev limiter? Is it the rear? If so, I'd still cut or remove the rev limiter wire at the TCI just to eliminate that as a possibility. I'm guessing if any part of that wire - even with no gages installed- was grounded it would make the TCI unhappy. As a first step maybe unplug the connector at the TCI and test the rev limiter wire for continuity to ground. This is all conjecture BTW as I have no knowledge of how the rev limiter circuit functions.  :-[  :P  :)
It is far better to grasp the universe as it really is then to persist in delusion, however satisfying or reassuring.  Carl Sagan

Re-Vision

Try checking for continuity between two-pin connector (R/W) going to rear coil and 6-pin connector on TCI (R/W) as well as the gray wire running between the same connectors. If these two wires have continuity and the gray wire is not grounded then suspect TCI and and pick-up coils as mentioned by Rikugan.     BDC

tig5


Today I disconnected the Y/B wire, no change. I also checked for continuity between the grey and R/W wires and this was fine. My Haynes manual suggests checking for resistance on the pickup coil wires at the TCI connection.It says to connect one lead of the ohmmeter to the black wire and the other to the red , then the white wire. With the ohmeter selector switch in position Rx10 you should get a reading between 99 and 121 ohms or the pickup coil assembly must be replaced. My multimeter didn't have anything marked Rx10 but under the "ohms" Latin logo thing at a value of 200 (from memory) I got readings of 113 & 115 on the two different wires. Then I figured I'd give the TCI connections a clean. I removed the unit and noticed that it had previously been glued back together. Cleaning the connections didn't help but I'm now suspicious of a TCI that's had some DIY work done on it. Is there any way to test the functionality of the TCI without another bike? Do I need to post it off to Roro ;)