And yet another T120...

Fast Eddie said:

Dave, I am just less respectful than you! I took the air cleaners off of the Bonnie, I took the Z plates off of the Commando, and I take GT handgrips off of most of my Brit bikes (tho they’re still on the Bonnie, for the time being)...!

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Heathen! )

Well just send it all to me when you take it off, like that awful tank, those fugly pipes, and as for that....etc etc ;o)

wavey_davey said:

Heathen! )

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bin' called worse... !

Wavey-davey - of course we can agree to differ. Bikes are supposed to be fun things, after all. And if we all agreed, it would get boring! The main thing is get out there and stretch those throttle cables.

I watched the vid of the Bonnie being ridden in Scotland - excellent

daveh said:

I watched the vid of the Bonnie being ridden in Scotland - excellent

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Yes, it sounded lovely didn’t it?

Wish he’d pressed on a bit more though, didn’t sound like he was revving more than 5k to me (at a guess) whereas 6k + is where the sweetest music is to be found !!

Fast Eddie said:

Yes, it sounded lovely didn’t it?

Wish he’d pressed on a bit more though, didn’t sound like he was revving more than 5k to me (at a guess) whereas 6k + is where the sweetest music is to be found !!

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They sound and go much better at 8k, but sensibly 6,300 rpm is the rev limit for any Triumph 650. Just make them pull harder and gear them higher. There is not one pre-unit 650 Triumph left racing in Australian historics. They have all blown-up through over-revving.

Yes, 8k will find the weak spot sooner or later. But even Edward Turner said 6,500. T140 factory red line was was 7000.

I’m comfortable taking mine to over 6k when the fancy takes me.

The reason there aren’t many pre units still racing in Oz is cos they’re all at least 65 years old and putting out double the intended horse power.

Neither of which were ever envisaged by Mr Turner.

The only surprise is that they survived so long !

Ayup chaps, well, I eventually got around to fitting the chokes t’ Bonnie.

Stroll on. What a faff!

Some cables I’d gotten from a trusted supplier were wrong. Then a nipple came off of another! Then I went forwards and backwards a dozen times trying to suss out the best routing. I fitted new featherlight throttle cables too whilst I was at it, even though I put new ones on a little while ago, they weren’t featherlite, and the difference is very noticeable! Note to self to insist on featherlite in future!

I actually ended up drilling the carb tops out and fitting choke cables with in line adjusters, as I think the later Bonnies had. It gives a smoother curve out of the carb top this way.

The chokes most certainly help with the cold running. However, I’m still fairly convinced that Sam was right, I need bigger pilot jets. I have [HASHTAG]#17s[/HASHTAG] at present and have ordered a pair of [HASHTAG]#19s[/HASHTAG]. At least it’s a doddle to access them wit the Premier carbs.

So, all being well, we’ll be all set to enjoy the spring weather, when it comes !

Bingo!

RGM to the rescue again with super fast delivery of...

A pair of #19 pilot jets, and...

Total success! Cold starting and low end running is now sublime.

Will probably end up taking the f@#*ing chokes back off it next...!

Fast Eddie said:

Bingo!

RGM to the rescue again with super fast delivery of...

A pair of #19 pilot jets, and...

Total success! Cold starting and low end running is now sublime.

Will probably end up taking the f@#*ing chokes back off it next...!

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Nigel, well done and it is very satisfying to get carburation right, because it can be a bear. I remember from previous posts that you have Premiers, although I haven't trawled through to see if they were they were sent jetted specifically for the T120.

I am going to try making cable elbows for the carbs on mine, or adapt some to fit. That would resolve the cable routing under the tank, which is also an annoying detail on Commandos. Why on earth did they not make elbows? Triumph did make a throttle cable with an elbow for the early Bonnies, but at the twist grip (for those flattish bars). It would not have taken much to do the same at the other end. I thought they were pretty thorough with most other fittings and fixtures on the 60s bikes.

Dave, if you’re prepared to go to a single pull throttle and fit a 2:1 cable junction under the tank then you might be interested in these:

https://www.ebay.co.uk/itm/TRIUMPH-...061439?hash=item41de5623bf:g:YKwAAOSw43haRoGY

I did a different secret tweak... I fitted a Cdo style exhaust bobbin as a rear tank mount (same UNF thread as the frame) it makes fitting easier and raises the rear, only a tad, you can’t really see it, but it’s just enough to give the cables a nice curve.

Don’t tell anyone though...

Ooh, those angled cables do look good, don't they?!

And a nice bit of lateral thinking on raising the rear of the tank a tad.

I have decided to fit flattish bars to start with, and I plan on fitting a 1 into 2 junction. Those elbows also have adjustment and I see that they can be ordered for Mark 1 concentrics. Thank you for fishing those out!

My rebuild has stalled somewhat over the last few months as I got involved in other things, but I am beginning to see light at the end of the tunnel.

Yet again, the site don't notify me of a new post so apologies for the late reply.

daveh said:

Nigel, well done and it is very satisfying to get carburation right, because it can be a bear. I remember from previous posts that you have Premiers, although I haven't trawled through to see if they were they were sent jetted specifically for the T120.

I am going to try making cable elbows for the carbs on mine, or adapt some to fit. That would resolve the cable routing under the tank, which is also an annoying detail on Commandos. Why on earth did they not make elbows? Triumph did make a throttle cable with an elbow for the early Bonnies, but at the twist grip (for those flattish bars). It would not have taken much to do the same at the other end. I thought they were pretty thorough with most other fittings and fixtures on the 60s bikes.

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Yes, the Premiers were bought specifically for the Bonnie, jetted accordingly.

But there is no doubt that the as supplied #17 pilot jet is too small.