T140E plug colour opinions

I put some leaded non ethonol petrol in the Trusty Triumph in order to check out the plug colour the old skool way.

I didn’t do a main jet plugs chop, this is simply showing what it looked like after a decent ‘spirited’ ride primarily on the needle / needle jet.

Look nice to me, what thinketh the collective ??

looking good from here

Looks good to me

Fast Eddie said:

I put some leaded non ethonol petrol in the Trusty Triumph in order to check out the plug colour the old skool way.

I didn’t do a main jet plugs chop, this is simply showing what it looked like after a decent ‘spirited’ ride.

Look nice to me, what thinketh the collective ??

View attachment 124016View attachment 124017

Click to expand...

In pre-lead free petrol days, when leaded 4 or 5 star petrol was the only stuff to use, I'd consider the 'right' colour on the insulator to be a pale brown, like milky coffee. That was with normal plugs (N3s or B8ES, not specials like those in the photos - don't know how much difference these make, colour-wise). These days, using super unleaded, my plugs (BR8 EIX) look just like yours. If my plugs had looked like yours in the 1980s I'd have thought the mixture too weak.

Tigernut said:

In pre-lead free petrol days, when leaded 4 or 5 star petrol was the only stuff to use, I'd consider the 'right' colour on the insulator to be a pale brown, like milky coffee. That was with normal plugs (N3s or B8ES, not specials like those in the photos - don't know how much difference these make, colour-wise). These days, using super unleaded, my plugs (BR8 EIX) look just like yours. If my plugs had looked like yours in the 1980s I'd have thought the mixture too weak.

Click to expand...

Interesting.

I know I have the slide cutaway perfect at #3.5, I know this coz I tried #3s.

These plugs were removed after a ‘normal’ ride, not a WOT plug chop, so, knowing the main jet wasn’t really in play much, and the slides are correct, we are really looking at the needle / needle jet area.

There is nothing about this bike to suggest anything other than a ‘standard 4 stroke’ 106 needle jet would be insufficient, and it has ‘standard’ needles (not the EPA lean needles). So all that’s left to consider is raising the needles a notch.

I might just give that a try…

Fast Eddie said:

Interesting.

I know I have the slide cutaway perfect at #3.5, I know this coz I tried #3s.

These plugs were removed after a ‘normal’ ride, not a WOT plug chop, so, knowing the main jet wasn’t really in play much, and the slides are correct, we are really looking at the needle / needle jet area.

There is nothing about this bike to suggest anything other than a ‘standard 4 stroke’ 106 needle jet would be insufficient, and it has ‘standard’ needles (not the EPA lean needles). So all that’s left to consider is raising the needles a notch.

I might just give that a try…

Click to expand...

Nigel, what drivability issue are you trying to cure by raising the needles?
Does it carburet cleanly when transitioning through the throttle openings?
Or is there a stumble?
Are just searching for more power?

concours said:

Nigel, what drivability issue are you trying to cure by raising the needles?
Does it carburet cleanly when transitioning through the throttle openings?
Or is there a stumble?
Are just searching for more power?

Click to expand...

The bike seems to fuel very well indeed. A slight ‘just off idle’ stumble has been cured by reverting to #3.5 slides (from #3).

I’m just responding to the feedback that it might look a little weak, and experimenting by raising the needles is a 5 minute job.

Am I searching for more power? What kind of lame question is that ?? I expected better from you…

Fast Eddie said:

The bike seems to fuel very well indeed. A slight ‘just off idle’ stumble has been cured by reverting to #3.5 slides.

I’m just responding to the feedback that it might look a little weak, and experimenting by raising the needles is a 5 minute job.

Am I searching for more power? What kind of lame question is that ?? I expected better from you…

Click to expand...

If some is good, more is better....


Over fueling works on Harley's...
Long stroke

concours said:

If some is good, more is better....


Over fueling works on Harley's...
Long stroke

Click to expand...

Yeah, I’m not looking to over fuel here. I think it’s right as it is personally, and I doubt that enriching the needle will help any… but there’s nowt wrong with doing a quick experiment…

Ok folks, here we have the same plugs, after the same ride, with the same leaded etho al free fuel, but with the needles raised one notch…

Fast Eddie said:

Ok folks, here we have the same plugs, after the same ride, with the same leaded etho al free fuel, but with the needles raised one notch…

View attachment 124176View attachment 124177

Click to expand...

Nigel, unless you're doing what you know is correct, wide open throttle plug chop, this is all fruitless. The partial throttle opening far lower cylinder pressures in all of that gives a reading that really is of little value.

Tune by the feel of the engine, seat of the pants dyno, throttle response. At partial throttle being too lean is not gonna be a problem as far as engine safety. You will not hole a piston, you will not seize a piston, or any of those horrible things at less than sustained wide open throttle. So shoot for what feels right with your butt and right wrist.

Hi Nigel, I personally think that your plugs with the revised setting look a much better colour, very similar to how my T140 plugs look and my T140 has no "holes" in the power delivery once warmed up.
Having said that, as you'll know, the dyno tester who did my T160 last year said that it's difficult to read plugs with modern petrol.

Reggie said:

Having said that, as you'll know, the dyno tester who did my T160 last year said that it's difficult to read plugs with modern petrol.

Click to expand...

I’m using leaded non ethanol fuel for these runs for that very reason.

And, of course, reading the plug colour on a T160 is notoriously difficult due ‘em burning 50/50 fuel and engine oil

concours said:

Nigel, unless you're doing what you know is correct, wide open throttle plug chop, this is all fruitless. The partial throttle opening far lower cylinder pressures in all of that gives a reading that really is of little value.

Tune by the feel of the engine, seat of the pants dyno, throttle response. At partial throttle being too lean is not gonna be a problem as far as engine safety. You will not hole a piston, you will not seize a piston, or any of those horrible things at less than sustained wide open throttle. So shoot for what feels right with your butt and right wrist.

Click to expand...

Not sure I fully agree. I’m not trying to prevent seizure etc, I’m ‘just’ trying to get the fuelling as good as I can (it’s already very good, I’m just being anal). That means getting all fuelling circuits as good as I can. Best way to do that (in the absence of an exhaust gas analyser) is to ride at specific throttle openings and plug chop for that particular fuelling circuit.

Using the butt is cool, but in my experience MY butt is not really objective or reliable enough to be used in isolation.

Fast Eddie said:

I’m using leaded non ethanol fuel for these runs for that very reason.

Click to expand...

Oh yes, you did say that didn't you. I'd read that the day before and forgotten when I posted.

Fast Eddie said:

And, of course, reading the plug colour on a T160 is notoriously difficult due ‘em burning 50/50 fuel and engine oil

Click to expand...

After 20 years of ownership, I'm still trying to solve that problem.

“I see Reggie is firing his Trident up…”

Cruel, but close to the truth.

How are you getting on with your Harris Bonnie Martin?

Putting may miles on it?

Is it behaving itself?

Fast Eddie said:

How are you getting on with your Harris Bonnie Martin?

Putting may miles on it?

Is it behaving itself?

Click to expand...

Having had it for 9 years last year, I hadn't ridden it much, about 1,500 miles, so I decided to start using it, and if I didn't like it, it was going to go.

So I took it out and didn't like the lack of low end power and vibration at 3,000rpm, and nearly aborted the ride, but I made myself continue
and started to rev it and ride it hard wherever I could, and then it all started to make sense. The vibration virtually disappeared at 3500+ rpm, the exhaust note changed to a growl and suddenly it had at least a bit of go. I'd been riding it like a Commando using mainly low revs, and now I really like it. It's very light and nimble.

Faults in the last 6 months are shocks leaking (replaced with Falcons yesterday), speedometer broken and stripped studs in the head No.9 and 10, so I've fitted some new cast iron barrels and pistons. I've already done over 500 miles on it this year running in the barrels and the bulb holder came loose in the headlamp the week before, so not perfect but it is oil tight and it is a fun machine. I'm surprised that it took me all this time to "understand" the Bonny.

I really quite like it.......at last.

Glad to hear you’ve finally learnt to like it!

I had a similar experience to you, after a while of riding mainly my Harley (1800cc) and Commando (920cc) I thought something was wrong with my humble T140 !

But I just had to re-learn how to ride it. I like it best between 4-6k rpm that’s really when it’s ’on cam’ and becomes quite a different bike. It’s safe and willing to go above that, there just seems little benefit in doing so to me. 4 to 6 might sound like a narrow range to keep it in to some, but with the excellent 5 speed box it’s a doddle, and FUN. Of course, it’s also perfectly happy tootling around at the speed limits at low revs too.

Humble as it is, it’s one of my favourite rides. It feels far lighter than it really is and is SO agile.

What CR pistons did you go for?

The low CR ones as used on late bikes and the Gilardoni barrels are my least favourite coz they totally waste the squish that’s built into the T140E head. I used the 8.6:1 ones, they have a perfect squish band to match the head but the factory had the gap way too big. I fitted a thinner head gasket and omitted the base gasket which tightened the squish nicely and raised the CR to over 9:1 I estimate.

One day I want to strip the motor and fit Hyde half race cams, but I’m loath to strip such a nicely running engine !

Is your Gilardoni barrel and pistons servicable apart from the pulled threads?