[0006] Best Post of 2013 - Engine & Gearbox, Strip & Rebuild

[mjc506]

Certainly not in the traditional sense (all cylinders spark at the same time) but perhaps in the sense that each cylinder sparks on every crank revolution.

don't know, just educated guesses really.

[greywolf]

Another possibility is the ECM uses a camshaft position sensor to distinguish the compression stroke from the exhaust stroke. I haven't seen anything in the manual that addresses the specifics on the matter.

Edit: As they say in New York, fagedaboutit. Only the Vee has a camshaft position sensor.

[mjc506]

GW, there's a camshaft position sensor on the Wee?

I guess it doesn't matter anyway - the lump runs

Tonight's job is another oil change, and I'll go over all the fasteners to find any that I forgot to tighten...

[greywolf]

GW, there's a camshaft position sensor on the Wee?

It was listed in the index. A further check finds no other reference. It's only in the Vee and Suzuki must have used the Vee manual as a boilerplate.  

I'll go back and edit previous stuff.

[mjc506]

No problem! I just panicked and thought I'd forgotten to install a component!

Here's the real video

[mjc506]

Updates:
Run through a few tanks. Fuel consumption seems back to normal/better. I'm convinced the engine is running better than I've experienced before. Even my pillion commented how smooth it was. I'm guessing a bit of love to the clutch, coupled with de-coking everything has helped a lot. I haven't managed as many miles as I expected (cursed weather), so I'm still on dino goop. I'll go synthetic @~1000miles. The oil changes have been easy. Very little crap in the oil coming out, although the first filter had a reasonable amount of aluminium in it. Nothing since. The last oil change was possibly a waste of time, as it came out the same colour it went in

No leaks/vibrations/bits falling off either

Problems:
Something isn't quite right with the electrics. Yesterday evening, after a bit of rain during the afternoon, I switch the bike on, thumb the starter and nothing happens. Switch off and switch back on again, and it starts fine. This morning, after a night of rain, switch on, fuel pump and STVA make the right noises, but no starty :( I get the solenoid click, but no movement. C12 on the dash - Crankshaft position sensor. I imagine I would have had the same come up last night, but it took a good few seconds for it to appear.

I can't get to the CKPs plugs at the moment, so couldn't check that, but the service manual seems to indicate that the engine should still crank with that sensor failed (FI Troubleshooting, C12 CKPS) This wasn't cranking even. The solenoid was clicking when pressing the starter button, but the starter wasn't running. (Sound familiar?) I'm wondering if the C12 is correct?

The solenoid clicked was fresh in my mind from the weekend, so I tried the spanner trick (shorting the solenoid terminals). Nothing. A tiny spark (really small?!) but not movement. In desparation, I left the ignition on, and jumped between the battery +ve, and the starter motor. Engine bursts into life! At this point, I'm late for work so I get on (not forgetting to pocket the handy length of wire, just in case...) and ride off. Bike runs perfect all the way to work. No other troubleshooting done yet. No FI indications, just C00 all the way.

So if it's running, then the CKPS must be OK, right? This solenoid deserves some investigation. I'll try jumping from battery +ve to the solenoid 'output' too to check the wiring between solenoid and starter motor.

Any other ideas?

EDIT: just been out to have a play. It's all working fine now - it's dried up a bit, so I'm thinking connections somewhere. Unfortunately, I left my multimeter turned on, so it's now dead  

[mjc506]

Yeah, it's small stuff, but annoying if I have to hotwire the bike each time it rains

There is no FI error at the moment (the bike is dry) and while the engine is running there's no issues.

I'm thinking worst case - some crap on the CKPS itself (entirely possible, it has just been rebuilt. In a garden...) giving a weak signal until the engine turns over, then it's cleaned off with oil. Or maybe just dirty connections (more likely, as the bike appears to be fine when dry, not fine when wet... but that doesn't explain why the bike runs fine once it's going? Perhaps there's enough signal there to run, but the ECM is more picky on startup?). In either case, the engine should still turn over, if not start. But it doesn't, so something's up there.

Can the ECM stop the bike turning over/starter running? Looks from the wiring diagram that it's possible, but also that the solenoid shouldn't click if that's the case. Wouldn't be inconcevable that both the CKPS and starter solenoid have issues.

[greywolf]

Your most likely problem is a connection on one of the large battery cables at either end of the cable or between solenoid and starter motor. The ECM isn't going to stop the starter motor when the solenoid is shorted. A marginal connection can cause FI errors by dropping the voltage to a sensor out of range.

[user650]

Sounds like bad earth or corroded lead some where, do you know how to do a volt drop test?

Using a volt meter set to handle 12 volts connect in parallel with the wire or part you suspect. There should be no more than half a volt reading MAX

e.g connect to bat positive and starter pos connector, try to start and check reading if no reading check the earth side I.e bat neg to starter case

hope you can make sense of this

[greywolf]

A voltmeter may not detect a marginal connection. It can look fine with no load but fail when a working load is applied and the starter is a very big load.

[mjc506]

Sorry, none of the above replies flagged this topic as 'unread' to me

As it's been dry for ages, the bike has been starting fine with no issues, so I've not had a chance to really troubleshoot. A voltage drop test was one of the first things I done, but I could find no problems.

This morning however, was a little damp... and the bike refused to start. Same symptoms. Unfortunately, I was late for work, so decided just to get it running rather than do a full diag.

Top box off, seat off, 'special tool' (length of wire) ready... first, I try shorting the solenoid (it's raining, and I don't really want to kneel under the bike to reach the starter)... a few sparks, not much else, until my little boy shouts "smoke!" Huh? he's pointing at the starter, and the 'smoke' is just a wisp of steam. I try again, looking at the starter... a few sparks from the wire, and yes - definitely some steam coming from the connection to the starter motor! A closer look reveals the water around the connection boiling, and a nice purple glow radiating from the connection. That'll be the problem then (I thought 12V shouldn't discharge like that?) I jump the bike again (battery +ve direct to the starter motor) and it starts fine.

Now at work, I have a better look. The bike dried off on the way, but has since sat in the carpark having a 'wash', so is wet again. I'm still getting that corona discharge around the connection. Could be a marginal connection plus salt doing that. It's pretty, but obviously not optimal No time to do much more at the moment, but I'll have a proper look once I'm home

[mjc506]

It appears to be fixed

Took the starter motor connection off the other night, and found it coated in a nice protective salt film Cleaned it all off (tesco value coke is fantastic for this sort of thing - not too aggressive unlike 'real' coke) dried up, put it all back together...

After a few more days of rain and wet, everything seems perfect

[MartinW]

Post now preserved as the 2013 best post.