Classic Triumph Bonneville

[Mr. Dazzle]

I suppose technically she's not that old! All the bottom end moving parts are new, new pistons, new pins, new rings, re-honed, new valve springs, new valves, con-rods polished, re-built oil pump...

[mangocrazy]

Hire a van and take it to the guy in Notts. If I was closer and hadn't recently had a hernia op I'd offer, but...

[JackyJoll]

Would it not be hard on the old girl running it on a dyno?

Running a warmed-up engine flat out for a short time? Not really.

It’ll sound “hard on the old girl” because you’re standing beside it in a shed.

[JackyJoll]

Hire a van and take it to the guy in Notts. If I was closer and hadn't recently had a hernia op I'd offer, but...

And my bad back too.

[Mr. Dazzle]

And this dashed idleness.

[Rockburner]

I just haven't got a van to offer!

[cheb]

I'll do the van thing , just cover my fuel costs.

[Le_Fromage_Grande]

I've got a trailer you can borrow, but tuning it by test riding it is a lot more fun, and you learn more.

Take it to Santa Pod for the day, you can do as many test runs as you can fit in.

[Hairybiker84]

Don't know about the Pukka pies, just a knack that it sounds like you're getting, when I started i only weighed 9 1/2 stone. Thankfully never tried any of the old 500 singles although I'd wager the CR500 I had was worse.
Personally, I would make sure the main was over-rich rather than under and then play around with needle height and taper (if there is such a thing on Amal's) to get it near enough. Very valid point made earlier though about making sure fuel flow to the carbs is sufficient.

[JackyJoll]

You’ll know it’s reached working temperature when things like this happen.

[Mr. Dazzle]

I fitted the new jets tonight....super easy on this bike, just pop the bowls off and change the brass bit. You can get bowls that have a screw port in the bottom to make it even easier, but I don't have those on both sides. On the side that does have it, I don't have any seals.



I've got 270 mains in there now, up from 250. I originally started on 220.

It deffo works loads better at full throttle now. There's still a hint of the funny noise and low revs/high throttle when hot, however at more than ~4500rpm it seems fine. Or I just can't hear it over those revs

Pulls pretty hard on full throttle at high revs. Above about 4k the gauge starts becoming a bit of a random number generator and AFAIK 7k is brave on this engine. Missed a gear one or two times and got a bike spike of revs, nothing escaped (that I know of). It shifts fast enough to make me think about how bad I am at braking on it, I need to get more feel for the front!

[Taipan]

Not familiar with these carbs but you always jet from the top backwards. Start with MJs then needle height etc. These bikes in various forms of tune have been around for years, so I'm surprised the correct jetting info for your set up isn't out there?

[Mr. Dazzle]

There's a million and one pages written on Amal tuning, as you say start with the main.

I've just been out for about 40 miles on it, it's generally OK. Looking at the plugs after a sustained run on the A5 a high throttle they're a smidge on the dark side. The electrodes are biscuit brown but the outer rim is dark, but not with loads of deposits.

[Supermofo]

Tuning an old Brit bike sounds like reading tea leaves!

[Mr. Dazzle]

At least with the leaves you get a nice cuppa too.

In reality you just need a dyno and an exhaust gas analyser. I've actually been looking to see if there's a Bluetooth one or something. The dyno is just to put load on the engine, I don't care about the BHP reading. So if you can find a device which reads AFR you can do it while riding along.

I never really thought to find out if such a thing is available before now.

[KungFooBob]

I think you'd need to get some bosses welded onto the down pipes and have them tapped for lambda sensors... in fact while you're doing that you could fit throttle bodies

[Mr. Dazzle]

Well quite...lambda probes have been in use for donkeys now. I just thought maybe you could get a standalone one now.

[A_morti]

You can, it's called an AFR gauge.
Plenty of options, this was the first that came up.

https://www.digital-speedos.co.uk/gauge ... cluded-p69

[Mr. Dazzle]

Just need to figure out how to get a lambda probe in there I guess they're all gonna use those screw in ones 'cause they're a cheap-as-chips off the shelf item that's used loads in cars.

[KungFooBob]

Looks like the kit comes with a boss and a probe... get the welder out!