Author Topic: Tiger 100 68  (Read 240 times)

Offline dynamic

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Tiger 100 68
« on: May 18, 2021, 06:50:35 PM »
having now done just 1000 miles on my machine since a full rebuild SRM timing side bearing / new sludge trap / crank regrind / rods /new cylinder / hepolite pistons / rings / head uprated to unleaded / valves /guides / springs / Morgo pump ( dust caps were within parameters )
I do find after a run of 60 miles + ( champion N 4s ) the right hand plug is always sooty ? left plug is always a nice light brown electrode dark outer ( no soot at all )
I have a new  concetric 620 on 180 main needle on middle groove starting is good tick over regular running Boyer charging is 14.4 + volts when revved
just curious about this uneven mixture situation ?

all input gratefully received
PS engine is not using any oil I have just changed from Morris running in grade to Morris gold 40 air filter is a standard new unit

Offline R

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Re: Tiger 100 68
« Reply #1 on: May 18, 2021, 10:49:15 PM »
A trace of burnt oil can leave a sooty or dirty plug.
I found this out with a Commando, where one oil seal had 'fallen off' the guide.
Usage was too small to be noticeable/measurable. And not noticeable to the rider.

If you have someone follow you though, they may observe a puff of blue smoke now and then.
If its on acceleration its rings, on deceleration its valve guides is the general guide.

It may improve with more running in though.
Have you given it a few BRIEF bursts of full acceleration to bed the rings in like the instructions say ?

Try swapping the plugs over too ...


Offline dynamic

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Re: Tiger 100 68
« Reply #2 on: May 19, 2021, 09:25:12 AM »
Hi I do vary the running speeds up to 70 so far I will swap plugs over and see if theres any change

Offline R

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Re: Tiger 100 68
« Reply #3 on: May 19, 2021, 10:39:38 PM »
Its that (brief) burst of HARD acceleration that seats the rings.
The gas pressure forces them into/against the cylinder wall ...

Offline dynamic

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Re: Tiger 100 68
« Reply #4 on: May 20, 2021, 05:56:21 PM »
thanks R just waiting for a non monsoon day to ride again

Offline dynamic

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Re: Tiger 100 68
« Reply #5 on: May 28, 2021, 10:38:18 AM »
had a 65 mile run yesterday with a slight AC turn on the airscrew plug chop now shows a near perfect colour
 (electrode light brown, plug outer body light black )
 I was using 2 year N4s now fitted with new N4s and purring along now 

Offline iansoady

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Re: Tiger 100 68
« Reply #6 on: May 28, 2021, 11:56:11 AM »
Light black - now there's an interesting colour!

Glad it's running well.
Ian
1952 Norton ES2
1955 Francis Barnett Cruiser 75