Roadside diagnostic and fix test

[Mark_h]

Originally Posted by Spank86

Can I point out that so far you've done pretty much what I said I'd do.

And both you and Tomor were acknowledged at the time. After dinner I shall mostly be doing what Daddyjob said.

Like I said, it's not uber-difficult stuff!

[Tomor]

want me to drop the stand over tonight?

Yes but that acknowledgements worn off now. I need the fuzzy glow it brings and yet I'm out of ideas.

[Mark_h]

So here’s what I did.

1. Splutter splutter stop.
2. Coasted into a bus stop to get off the road and relative safety.
3. Restarted – revved by itself to 5k then stalled. Sounded horrible.
4. Restarted – revved by itself to 5k then stalled.
5. Thought perhaps ECU “confused” so switched ignition off completely, counted to 10 and restarted.
6. Restarted – revved by itself to 5k then stalled.
7. Opened fuel tank lid to check there was fuel in there and to make sure no massive positive or negative pressure.
8. Restarted – revved by itself to 5k then stalled.
9. Restarted and opened throttle. Found that if you opened it a fair way to get the revs upto 6k it ran but sounded like a manic cement mixer. Dropped throttle, instantly stalled.
10. Thought – Oh bugger! And looked for somewhere to fix it. Saw closed shop on the other side of the fairly busy road so thought I’d get it over there. Decided that I should start it and rev it and drive it over there as otherwise good chance of getting killed pushing large bike up hill across a busy road.
11. Restarted – opened throttle, ignored horrible noises, saw gap, let out clutch and stayed put. Oh bugger! I’ve got big clutch/gearbox/expensive problems. Then notice neutral light. Slip it into gear and nearly catapult myself into next week. TOP TIP. 6k is not a good engine speed to put it into gear even with the clutch in!
12. Ride across road with both feet on ground in case it stalls or leaps into full life ( I look like Jammy riding into Loomies for those that were there)
13. Helmet off, tool kit extracted and thank kindly passer-by who wants to know if I want a lift to the petrol station. Check phone, no signal.
14. Kneel by right hand side of bike. Check vacuum take-off extensions still in place – yep.
15. Check front plug in place and cap secure – Yep (can’t see rear plug yet)
16. Check both cans equally warm – Yep but I’ve been riding miles so hardly surprising
17. Restarted and confirmed no massive plumes of white, black or blue smoke from either can.
18. Removed side panels and rider seat.
19. Checked under seat for battery fitment – OK
20. Checked under seat for weird burning electrical smells – None
21. Lifted tank and gave myself a slap for leaving tank prop in shed at home.
22. Checked rear plug in place and cap secure – Yep
Doubt a duff plug would cause revs to raise but suppose it could have spooked the ECU somehow.
23. Removed airbox lid and filter cursing the lack of tank prop. 6 philips screws carefully placed in side panel along with the 6 already removed hex bolts to get the tank up. Moved side panel out of kicking range (lesson learned long time ago)
24. Checked that both butterflies moved with throttle – Yep
25. Check no bits of engine or random stuff in airbox housing – All OK
26. Check for sprayed fuel – None
27. Turn on ignition and see both secondary valves do their fancy open close trick and still no sprayed fuel – So far so good.
28. Start bike. Revs raise to 5k then bike stalls. Cement mixer noises louder and some mist around rear throttle opening. – Aha! That’s not right.
29. Waggle throttle body and discover it’s come away from the inlet manifold – Aha!
Retrospective symptom analysis says rear throttle running with effectively fully open throttle so ECU goes mental as front body on tickover. Think to myself we may be in luck here.
30. Loosen the jubilee clip on the bottom or the throttle body rubber and push it back onto inlet manifold with a very satisfying squelch noise. Tighten jubilee clip – Right – hold breath…
31. Restarted – bub.bub.bub.bub.bub.bub.bub.etc… rev it a little brum.bub.bub.bub.bub. – Big self satisfied smile.
32. Refitted airbox stuff cursing the lack of tank prop with every screw. – Fired it up again just to be sure bub.bub.bub.bub.brum.bub.bub.bub.bub
33. Fitted tank, seat, side panels then the hardest bit.. getting the tool kit back into the box and the door on. – Fired it up again bub.bub.bub etc.
34. Wiped hands on grass, final check for left over bits, tools etc then rode home.

Now I’m no mechanical genius but I went from broken down to back on the road again in less than 15 minutes . Would have taken longer to walk to a phone box let alone wait for a recovery truck. The actual fixing took about 2 mins. It took longer to get the tank up than anything else.

I’d thoroughly recommend getting comfortable lifting your tank as once you’ve done that you can probably fix a significant number of faults like loose sparkplug caps, fallen off fuel lines and, as in my case, dislodged throttle bodies which can happen to us all and are pretty simple to sort yourself. Also if you take a look under your tank once in a while you’ll get used to what it’s supposed to look like so if you find a black pipe wedged somewhere you have half a chance of remembering where it used to be.

I fully appreciate that some people have no desire to know how it all works underneath the shiny bits and that’s absolutely your choice but if you find yourself at a loose end one weekend why not take the time to familiarise yourself with some of the basics to save yourself a long wait on the side of the road.

Oh and congratulations to Sir Trev for earliest identification of fault. Your prize is in the post.

Originally Posted by Thunderace

Check the fuel, then the plugs, then air intake. If all three are fine move on to mechanical and electrical

Originally Posted by Mark_h

7. Opened fuel tank lid to check there was fuel in there and to make sure no massive positive or negative pressure.
15. Check front plug in place and cap secure – Yep (can’t see rear plug yet)
22. Checked rear plug in place and cap secure – Yep
Doubt a duff plug would cause revs to raise but suppose it could have spooked the ECU somehow. Correct!
23. Removed airbox lid and filter
29. Waggle throttle body and discover it’s come away from the inlet manifold – Aha!

Fuel, spark, air! Nuff said!

Originally Posted by Thunderace

Fuel, spark, air! Nuff said!

So looking in the tank for petrol, making sure the plugs spark, and breathing near the bike to be sure you're in the atmosphere is all you need to do?

Originally Posted by Spank86

So looking in the tank for petrol, making sure the plugs spark, and breathing near the bike to be sure you're in the atmosphere is all you need to do?

Basically Ad yes, if the plugs work and are fitted correctly, if you have fuel and its being delivered correctly, and if you air intake is fitted correctly, usually an engine will work.

Even you know the basics, suck, squeeze, bang, blow, if an engine can do this 99% of the time an engine will work, unless there is an engine management problem or something broken inside the engine.

[Sid Squid]

A while back I fixed an Orger's SV1000 which had had some monkey screwing around with it who had left the front inlet rubber loose and the 'O' ring damaged, one, (obviously non standard), screw bottomed in the hole before the rubber even touched the head! Similar enough symptoms to your machine, and effectively the same fault, albeit by a different route.

It doesn't happen often, but I've known SV1000s - not commonly, but several of my knowledge do it, pop back when on tickover. It will sit there idling nicely until the instant the throttle is opened, whereupon it spits back and dies. On occasion the spit back is sizeable enough to make quite a noise, I suspect the throttle bodies/airbox etc shift enough to cause the airbox the bump the tank/frame/whatever. I imagine something similar occurred with your bike, perhaps the inlet clamps were not fully tight?