Classic Triumph Bonneville

[JackyJoll]

I see that the T120TT, with pistons like yours, used Champion N58R, which is an obsolete racing plug.

[Mr. Dazzle]

It's got NGK B8ES in at the moment, which so far as I can work out is equivalent to a N3C Champion.

Add it to the pile of things to worry about.

[JackyJoll]

They certainly still make racing plugs.

https://www.jdm-sparkplugs.com/shop/racing/b10egp/

[Mr. Dazzle]

Just been out for a spin...tis the first time I've been out on a bike, any bike, "just because" in a long long time. WTF I chose today I have no idea, its three million degrees out there and that engine puts out ALOT of heat.

Also. I broke down.

This one was an easy one though, the battery connector had vibrated off the terminal. Shes got a non standard battery, its actually intended for UPSs in fire alarms and the like and is theoretically better suited to long periods of non use. The connectors aren't bolted to the terminals though, which is a downside.

A fag butt from the side of the A5 makes the perfect anti vibration spacer. I'll redo the connectors with ones that actually fit the terminals! Duck taping them in place will probably also help.

[Mr. Dazzle]

I've just checked on Google Maps...that ride was 20 miles. That's a new record! Still the one breakdown though

I'm also outta gas now, I had to go on to reserve. I think it's a 16 litre tank and the reserve is probably a litre or two. I've probably used a bit more than 3 gallons to do about 100 miles by now, so sorta 30-40mpg. Maybe.

I don't actually care that much, just curious. You piss a teaspoon or two of fuel on the floor just tickling the carbs

[mangocrazy]

Just been out for a spin...tis the first time I've been out on a bike, any bike, "just because" in a long long time. WTF I chose today I have no idea, its three million degrees out there and that engine puts out ALOT of heat.

Also. I broke down.

This one was an easy one though, the battery connector had vibrated off the terminal. Shes got a non standard battery, its actually intended for UPSs in fire alarms and the like and is theoretically better suited to long periods of non use. The connectors aren't bolted to the terminals though, which is a downside.

A fag butt from the side of the A5 makes the perfect anti vibration spacer. I'll redo the connectors with ones that actually fit the terminals! Duck taping them in place will probably also help.

And I got lectures from you about my VFR brakes and Falco bars...?

[JackyJoll]

I sometimes punch a dent in the back of a female spade, to make it grip better.

Looking at the wiring, was your wife’s dad colour blind?

And crimpophobic!

[Mr. Dazzle]

The best bit is, this wiring was done by my FiL and his BiL (i.e. my wife's uncle).

FiL was a cheif tech in the RAF for >30years (well he obviously want a chief for that whole time), BiL was also an RAF techy type before leaving to become....an automotive electrician

[Skub]

The best bit is, this wiring was done by my FiL and his BiL (i.e. my wife's uncle).

FiL was a cheif tech in the RAF for >30years (well he obviously want a chief for that whole time), BiL was also an RAF techy type before leaving to become....an automotive electrician

A fair few folk who've worked on aircraft develop a dislike of flying. They know too much about what work gets passed.

[Mr. Dazzle]

Said uncle still wears his 10 years long service award watch he got from the RAC. His present job is breaking bikes on eBay.

Never buy a plumbers house or a mechanics car right?

[Noggin]

I'm really enjoying this thread but its certainly made me get rid of any romantic ideas I've sometimes had of getting an old brit bike! Good on you for persevering with it!

I bloody love this thread even though I don't really understand at least half of it!! LOL

But, I must be a weirdo cos it hasn't put me off - I'd still love an old brit bike!

[JackyJoll]

Said uncle still wears his 10 years long service award watch he got from the RAC. His present job is breaking bikes on eBay.

Never buy a plumbers house or a mechanics car right?

And don’t do what I do. Do what I say.

[Noggin]

Of course it's supposed to leak. It's a Triumph...

Ummmm - I was once told that Triumphs don't leak.. they just mark their territory

[Le_Fromage_Grande]

On my Kawasaki I separated the 4 wires it needs to run from all the other wiring needed for other things, makes the wiring tons easier. I need to do the same on my YPVS.

[Mr. Dazzle]

I've done at a guess maybe 30-40 miles on it tonight generally without incident. Also filled up with Shell V Power (£2.15 / litre!) and confirmed the tank is 3.5 gallons.

A and B roads suit her much better than modern straight dual carriageways and roundabouts. The engine is so well suited to the road, the only let down is the vibes. It's super tractable though and really lively off the throttle with tonnes of torque. Also got an indicated 110mph which can't be far off the magic ton in real life, s'got plenty more in the tank at that speed, but I can't give it full beens as per the below.

"Generally without incident" cause the horn fell off. Not a loose bolt this time though, the bracket fatigued and cracked!



Still not happy above about 3/4 throttle though, the high speed electrical arc sound is still there. There are the slightest vibes too, almost sub conscious.

I'm tempted to try a few things:

- Get some fancy octane booster just to see if that makes the sound go away. Not a permanent solution, but it will confirm what the sound is?
- Switch to a cooler spark plug. It's got B8ES plugs at the moment which are stock I think. My high compression pistons (>20% higher than stock) will make the chambers hotter, so maybe the plug is over heating and acting like something of a glow plug. I've got some cooler B7ES in the garage which might be worth a quick try.
- Go down a size on the needle jet (back to stock) and lift the needle up a step. This should have the effect of making the mixture richen up faster/sooner as you open the throttle. Mighr then need to change the slides to be richer too, but they're already more rich than stock.

[Le_Fromage_Grande]

B7ES is hotter than B8ES, colder is B9ES.
Your jetting idea sounds wrong, I assume by needle jet, you mean the main jet that screws into the emulsion tube, if you put a smaller one in it will make the mixture leaner everywhere except tick over, are you sure you want a leaner mixture flat out as it's already running hot.
If I were you I'd just lift the needle a notch, making part throttle richer, what ever you do only change one setting at a time, otherwise you won't know what to change back of it's worse.

Also how does changing the slide effect the mixture - I'm not familiar with Amals, I thought they were very similar to Mikuni slide carbs.

[Mr. Dazzle]

The slide cutouts change the mixture at low throttle. They come in different numbers so you can tune the mixture.

Right you are about plugs though, I need B9ES.

By needle jet I mean the one the needle actually sits inside, i suppose its equivalent to the emulsion tube. Its the upper of the two light great bits here, the lower one is the main jet in Amal land.

Edit: I realised my original post is misleading. Changing the needle jets will make it leaner. Lifting the needles will make it richer at high throttle and make it richen up sooner. The latter might fix my potential lean running issue at higher throttle but make it too lean at low/mid...which is why I said maybe o need to change the slides too. If I only lift the needles it'll probably be TOO rich everywhere.

Or maybe I just need bigger mains. I'm already up 3 sizes i think.

Or maybe running a 53 year old engine with 20% higher compression and unleaded fuel is just daft

[Le_Fromage_Grande]

So the slide cut out does the same job as the pilot jets on a Mikuni, as it doesn't appear to have a pilot jet, so tightening the slide should only effect the mixture when the slide is closed?

Needle jet is an interesting thing, does it have holes in the sides like an emulsion tube?

Is the needle jet smaller or bigger than the main jet?

[Mr. Dazzle]

Needle jet is just a brass plug with an 'ole in the middle. The main jet is the same and just bigger. The two are in series. You could take the mains out and you probably wouldn't even notice 90% of the time!

Actually I'm not sure if the main is bigger. When you open it to full throttle the needle lifts all the way out of the smaller hole in the needle jet, jt rests in the bigger 'step'. So it must be at least the same size as the main otherwise it'd throttle the main?

Theyre quotes with numbers like "220" which AFAIK is flow rate with a certain pressure head. The needle is a smaller number (about 106) but maybe they're measured differently.

Edit: it does have a pilot circuit though, that's what the diagonal red line is in the pic. Not really a jet though, just a hole.

[Le_Fromage_Grande]

The red line is an air bleed isn't it, on a Mikuni that's controlled by an air jet in some carbs.

I'd have thought the needle jet would have to have a higher flow rate than the main jet, otherwise there'd be no point having the main jet.

The numbers probably mean different things, Mikuni do a 220 and a 110 jet that both flow very similar amounts, I've no idea what either of these numbers refer to, I think they're just Mikuni part numbers.