Advice pls.. (1 Cylinder firing)

24-12-2003, 05:08 PM

bike problem

M600 '94

The Horizontal cylinder on my Monster decided to stop working last night.
The plugs had only been changed 3 days ago.
Sprayed WD40 through the carbs two days ago, to try and fix a problem with the monster starting in the cold (which did work)

The Plug in the vertical cylinder is fine (Going by Haynes manual photo)
The plug in the horizontal cylinder is jet black.

Whatever I try I cannot get the horizontal cylinder to catch.

I am unsure on what could be causing this problem, and basically was wondering if any of you could point me in the right direction to start troubleshooting. N.B It backfired like a machinegun for a few seconds before dieing completely.

From My limited mechanical knowledge I can deduct that it would be caused by one of the following (blocked carb, b0rked HT lead or the more expensive piston/cylinder barrel faliure.)

If you could advise me which areas to check first, as obvoiusly I dont want to get started on a Top-end rebuild and find out it was something stupidly simple that I missed.

TIA for any pointers.

25-12-2003, 03:32 PM

If you have recently changed the plugs, I would swap them round and/or check that you are getting a spark on the front cylinder. I went through the whole routine of swapping coils, checking ignition box etc. on my Commando once, only to find that it was a plug fault on a 30mile old plug!

gary tompkins · 25-12-2003, 09:46 PM

A few club members have also had problems with ignition pick-ups packing up on one cylinder. So if plug, HT lead and coil all check out ok it could be the next thing to look at?

Would have tried to point you to a previous couple of threads - but all the history on the forum prior to about a month ago seems to have been lost in the server move

02-01-2004, 09:00 AM

OK changed the plugs again, and it worked for a day.
Could not use it the next day as the throttle had frozen completely open

Tried again this morning and it was backfiring again, I think back down to one cylinder. Need to check the plug on the horizontal cylinder again.

I am thinking maybe its the piston rings letting some oil into the combustion chamber and hence fouling the plugs all the time....would this be a reasonable conclusion to draw?

If it was this I guess the fix is new pistons rings, and or pistons and barrels depending on how the damage is....

04-01-2004, 11:00 AM

Plugs foul on the front cylinder in winter, they all do it to a greater or lesser extent.
Try running on optimax or add a little Silkoline Pro boost to the tank, it does help.
The carb icing buggers the mixture, the front pot is stuck out in the freezing cold while the rear one is nice and warm....
Recipie for fouled plugs.....
Might be worth going to a local Dyno to check the mixture is ok ? because the cold will just exagerate any fuelling errors
HTH
Dom

sidrat · 04-01-2004, 05:23 PM

You could also try a colder plug in the front cylinder, just go down one heat range. The plug fouling will probably not be oil in the cylinder, if it was you would see black smoke coming out of the back of the exhuast as it was being burnt.

06-01-2004, 10:51 AM

Or
how about taking the plug cap off cutting 6mm of the ht lead and rescrewing it back on, these connections can go loose over time, if that gives any success then invest in a new pair of caps.

06-01-2004, 08:23 PM

Excellent thanks for all the tips people...

I shall try all that advice and see what it does.

being a bit of a mechanical n00b I tend to panic and think the worst straight away.

Shall check the mixture first then try the plug idea, then the new HT leads if needed.

24-12-2003, 05:08 PM	#1
trichome Guest Posts: n/a	Advice pls.. (1 Cylinder firing) bike problem M600 '94 The Horizontal cylinder on my Monster decided to stop working last night. The plugs had only been changed 3 days ago. Sprayed WD40 through the carbs two days ago, to try and fix a problem with the monster starting in the cold (which did work) The Plug in the vertical cylinder is fine (Going by Haynes manual photo) The plug in the horizontal cylinder is jet black. Whatever I try I cannot get the horizontal cylinder to catch. I am unsure on what could be causing this problem, and basically was wondering if any of you could point me in the right direction to start troubleshooting. N.B It backfired like a machinegun for a few seconds before dieing completely. From My limited mechanical knowledge I can deduct that it would be caused by one of the following (blocked carb, b0rked HT lead or the more expensive piston/cylinder barrel faliure.) If you could advise me which areas to check first, as obvoiusly I dont want to get started on a Top-end rebuild and find out it was something stupidly simple that I missed. TIA for any pointers.

25-12-2003, 09:46 PM	#3
gary tompkins 1/2 man - 1/2 pogo-stick Join Date: Aug 2002 Location: Dartford, Kent Bike: M900ie Posts: 7,241	Dodgy pickups on early 600's A few club members have also had problems with ignition pick-ups packing up on one cylinder. So if plug, HT lead and coil all check out ok it could be the next thing to look at? Would have tried to point you to a previous couple of threads - but all the history on the forum prior to about a month ago seems to have been lost in the server move __________________ GT Fully paid up member of the S.A.S. (Scottoiler Appreciation Society) 27,000 miles on original chain - and still going strong!

04-01-2004, 05:23 PM	#6
sidrat ex S4rs owner Join Date: Oct 2003 Location: Lincolnshire Bike: S4r Posts: 179	You could also try a colder plug in the front cylinder, just go down one heat range. The plug fouling will probably not be oil in the cylinder, if it was you would see black smoke coming out of the back of the exhuast as it was being burnt. __________________ Back on a Monster again!

25-12-2003, 03:32 PM	#2
DavidT Guest Posts: n/a	If you have recently changed the plugs, I would swap them round and/or check that you are getting a spark on the front cylinder. I went through the whole routine of swapping coils, checking ignition box etc. on my Commando once, only to find that it was a plug fault on a 30mile old plug!

02-01-2004, 09:00 AM	#4
trichome Guest Posts: n/a	OK changed the plugs again, and it worked for a day. Could not use it the next day as the throttle had frozen completely open Tried again this morning and it was backfiring again, I think back down to one cylinder. Need to check the plug on the horizontal cylinder again. I am thinking maybe its the piston rings letting some oil into the combustion chamber and hence fouling the plugs all the time....would this be a reasonable conclusion to draw? If it was this I guess the fix is new pistons rings, and or pistons and barrels depending on how the damage is....

04-01-2004, 11:00 AM	#5
M900Dom Guest Posts: n/a	Plugs foul on the front cylinder in winter, they all do it to a greater or lesser extent. Try running on optimax or add a little Silkoline Pro boost to the tank, it does help. The carb icing buggers the mixture, the front pot is stuck out in the freezing cold while the rear one is nice and warm.... Recipie for fouled plugs..... Might be worth going to a local Dyno to check the mixture is ok ? because the cold will just exagerate any fuelling errors HTH Dom

06-01-2004, 10:51 AM	#7
Ade Guest Posts: n/a	Or how about taking the plug cap off cutting 6mm of the ht lead and rescrewing it back on, these connections can go loose over time, if that gives any success then invest in a new pair of caps.

06-01-2004, 08:23 PM	#8
trichome Guest Posts: n/a	Excellent thanks for all the tips people... I shall try all that advice and see what it does. being a bit of a mechanical n00b I tend to panic and think the worst straight away. Shall check the mixture first then try the plug idea, then the new HT leads if needed.