Sooty Plug

Go down

Sooty Plug Empty Sooty Plug

Post  Mauser on Wed Aug 14, 2019 8:57 am

Yes I know I ride slow and that won't help matters, I did 32 miles yesterday in 2 hours Smile.
Is there a way to lean my bike to suit this riding style ?, air filter clean before you ask.
Sooty Plug Sooty

_________________
Current ~  XR650R ~ RT2 360 ~ ZX12-R ~ DT175MX
Previous Bikes XR250R ~ DT125R ~ GPZ1100 ~ RD350LC ~ XL125R ~ MT5
Mauser
Mauser
Administrator

Joined : 2010-09-13

Posts : 1910
Location : UK
XR650R Year : 2002

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  BuRP on Mon Aug 19, 2019 10:55 am

A plug fitted by a manufacturer has a certain heat-grade - a socalled 'hot' or 'cold' plug.
This heat grading refers to the length of the ceramic isolation tip which also is an insulation tip - as this determines how easy-or-not the plug's central electrode can shed it's heat.
This is done to keep the plug's tip hot-enough during operation for burning itself clean.
A manufacturer will experiment with different engine loads to see which plug works best, and then will recommend a certain plug only.
If one goes colder the plug may foul.
If one goes hotter the compression ration is upped marginally but more importantly the tip will run hotter, and this may induce pinging/detonation. In addition the plug's life will be shortened or the central electrode may melt.
It is therefore crucial that one adheres to the recommended plug!

However, there's always a but.... which in this case is that if one more idles than runs the engine, i.e underloading it, the plug will not have a chance to reach the same temperature the manufacturer's engine did during their testing, so it fouls - and only then it is OK to install one-grade warmer plug.
Note also that running this desert racer only in the lowest part of the rev range will automatically mean that the mixture is on the rich side, if only because an accelerator pump is missing.

Leson Wan over Maussie: just install a size smaller idling jet, and if that does not cure your fouling woes also install a one-grade warmer plug, and for the latter you'll have to google which number is warmer, I dunno.
BuRP
BuRP
XRR Monger

Joined : 2010-10-18

Posts : 1651
Location : Pretoria Souf Efrika
XR650R Year : 2007

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  BuRP on Mon Aug 19, 2019 11:02 am

Adding to the above rather than editing, I'd start with a colder plug.... because with a notch smaller idling jet (which is the one you run on mostly) one will have less power, obviously.

And, instead of smallering (yes, that's a word, re-read if you don't believe it razz ) the idling jet you could also lower the jet-needle by raising the clip a notch... or two.
Mind, disclaimer etc, I know you're the absolute only chap I know of which may do this, for anyone else will run it at high if not top power at times.... and then things may or will go wrong Shocked  but not when you're on it! Bump
BuRP
BuRP
XRR Monger

Joined : 2010-10-18

Posts : 1651
Location : Pretoria Souf Efrika
XR650R Year : 2007

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  Mauser on Tue Aug 20, 2019 8:33 pm

Forgot to mention for the first time since owning my baby she is difficult to start?, normally 1st kick but sometimes she is being a real pig and taking 30 kicks and waiting lol.
Tried 2 plugs still same she started today after 3 kicks and ticks over sweet....but its annoying when she won't go BRP smile
Thanks for plug info Burpy... Cool

_________________
Current ~  XR650R ~ RT2 360 ~ ZX12-R ~ DT175MX
Previous Bikes XR250R ~ DT125R ~ GPZ1100 ~ RD350LC ~ XL125R ~ MT5
Mauser
Mauser
Administrator

Joined : 2010-09-13

Posts : 1910
Location : UK
XR650R Year : 2002

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  BuRP on Wed Aug 21, 2019 2:40 pm

Check if the little springloaded flap in the large choke-flap works?
If not fix this, but if all's honky-dory then I'd drop the jet-needle a clip.

Mind, if it again budges to start then perhaps, without doing anything else I'd put a brandnew plug in - and see if this makes a difference.
If it thus starts normal then the sooted plug is just useless and only suitable for File 19 Bump
BuRP
BuRP
XRR Monger

Joined : 2010-10-18

Posts : 1651
Location : Pretoria Souf Efrika
XR650R Year : 2007

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  Mauser on Fri Aug 23, 2019 5:30 pm

BuRP wrote:Check if the little springloaded flap in the large choke-flap works?
If not fix this, but if all's honky-dory then I'd drop the jet-needle a clip.

Mind, if it again budges to start then perhaps, without doing anything else I'd put a brandnew plug in - and see if this makes a difference.
If it thus starts normal then the sooted plug is just useless and only suitable for File 19 Bump

Not keen on moving the clip, it's been like this for years without any problems, will buy a new plug Smile.

_________________
Current ~  XR650R ~ RT2 360 ~ ZX12-R ~ DT175MX
Previous Bikes XR250R ~ DT125R ~ GPZ1100 ~ RD350LC ~ XL125R ~ MT5
Mauser
Mauser
Administrator

Joined : 2010-09-13

Posts : 1910
Location : UK
XR650R Year : 2002

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  BuRP on Thu Aug 29, 2019 12:01 pm

And, Operation PlugSwap carried out - and if so, was it one you would recommend? Question
BuRP
BuRP
XRR Monger

Joined : 2010-10-18

Posts : 1651
Location : Pretoria Souf Efrika
XR650R Year : 2007

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  Mauser on Sun Sep 01, 2019 7:25 pm

BuRP wrote:And, Operation PlugSwap carried out - and if so, was it one you would recommend? Question

Sorry not swapped it yet been on holiday razz

_________________
Current ~  XR650R ~ RT2 360 ~ ZX12-R ~ DT175MX
Previous Bikes XR250R ~ DT125R ~ GPZ1100 ~ RD350LC ~ XL125R ~ MT5
Mauser
Mauser
Administrator

Joined : 2010-09-13

Posts : 1910
Location : UK
XR650R Year : 2002

Back to top Go down

Sooty Plug Empty Re: Sooty Plug

Post  Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum