Manky's XS650 Yamaha

[Archie]

It's ok. I'm into my 3rd one in that time frame.

But I do keep getting them for free 😀

[Archie]

As in 3rd not completed

[Dslam]

The saga continues...............
Spent some time on the carbs again yesterday and was struggling to work out why I couldn't get the two cylinders to balance throughout the rev range so I went back to basics.
Rechecked timing OK
Rechecked tappet clearances OK
Rechecked compression. Improving and balanced on both cylinders and not leaking down.
Conclusion. Must be carbs.
Removed them both and stripped down and started comparing the two. We know they are odd because one has a screw in pilot and one has a pressed in jet and both are pre Burlen. Did some research and found the pressed in type has a 20 pilot and the screw in is 25. Hmm, thought I, that ain't helping.
Then I noticed that the needles were slightly different. One has a shallower taper than the other and the end is subbed. The other is steeper tapered and point ended and the taper begins earlier and to add insult to injury, the needle jet is lower in the body than the other as well. It looks like someone in the past has, unsuccessfully, tried to balance the two by playing with the needles. I then realised that the needles were slightly different lengths too which made the clip slots at different heights. Ruddy Norah I am really in a hole now!!
The exhaust on the left side was blowing at the head which I tried to resolve but it seems that the flange (love that word) is cracking away from the pipe where polishing prior to chroming has thinned the weld to paper thin and the pipe itself is bearing on the clutch cover forcing it up, stressing the flange (that word again) allowing gasses to pass. Poo thought I. (feel free to insert suitable expletive!)
Nothing for it. New carbs. Andy wants a useable and reliable motor as do we all but unfortunately these carbs are not going to provide it.
Had a conversation with Lord Monkey and new carbs will be procured and the exhausts remade in stainless by Andy's Brother. An expert in the field (no pun intended) of pipe fabrication then back to Ches Dslam for the final tune up.
All in all a wallet numbing experience but I hope the end result will be worth all the effort and that his Mankyness will feel the same.

[Olds]

Oh dear ! 
And I though I'd had a bad day.

[Manky Monkey]

That one step forward, one step back thing -yeah, that's getting annoying now
Nothing that can't be fixed &, as Mr 'Slam said, I intend to keep this one for a very long time, so may as well get it right. I trust his judgement & did ask him to do whatever he thought was necessary, so if he says new carbs, it gets new carbs. No point trying to bodge it cos I'll be the one who has to live with the bodge.
Definitely no more projects. Ever.

[kapri]

" No more projects ever" Yup, I said that as well... new one arrives next week ! LOL  Seriously though I do need to sell some cars as back up to 11 vehicles at the mo (thanks to Marians pension payout !!;) )  ...and it's HER not me before anyone asks.

[Dslam]

Never say never.
I have said that many times and what do I do. You guessed it!
In any case the man cave would be ever so empty and boring at least Mrs Dslam knows where all my mistresses are.

[Manky Monkey]

You're not supposed to encourage me! I just want to get out & clock up some miles on the projects I've already got.

[Baychimp]

Any chance of selling the others Andy? somebody may need one or other to make a pair.

[the coppersmith]

In any case the man cave would be ever so empty and boring at least Mrs Dslam knows where all my mistresses are.  Now I know why my wife encourages me to keep a little something in the cave

[morrag]

Andy, before you dive in, why not fit the original Japanese carbs, and just weld repair the leaking exhaust flange, for now, then see how things are........anyway, that's what I would do. If all is well, then spend the dosh! ...Morrag

[Manky Monkey]

Yes Bob, nothing wrong with the carbs individually, they just don't work as a pair.
Dave, I haven't got the original carbs any more, or the inlet rubbers. Yeah, I could weld up the existing pipes for now, but like my truck, I don't want to run it bodged up -I want it properly sorted. Just going to take a bit longer than I'd hoped.

[Dslam]

In any case the man cave would be ever so empty and boring at least Mrs Dslam knows where all my mistresses are.  Now I know why my wife encourages me to keep a little something in the cave

DIRTY BOY

[Manky Monkey]

Many thanks to Mr 'Slam for returning the "Frog" to Basingstoke this evening.
I was tempted to chuck it in the garage, lock the door & never return, but I've had time to reflect & will persevere. I've always said it'll be my last bike build, so if it takes a little longer to get it right, it'll be worth it.
So, first job will be to phone Burlen Fuels in Salisbury & order a pair of carbs, fitted with the jets, slides & needles as listed by Andy after consulting with several of his classic bike colleagues.
Then I'll ring Armours in Bournemouth. They make exhausts for classic bikes. The exhaust note's a little ...harsh. Ideally I'd like it no louder than a standard XS but we'll never achieve that. Not so much the volume, more the pitch. I'd like to soften it a bit & Mr Dslam agrees. He suggests a pair of short Triumph Tiger Cub trials silencers. If I can find a pair in stainless & they're physically small enough, I'll fit them halfway along the pipes, more or less where the heatshield is. That'll still leave the long parallel tail pipes, which I really like. I'm going to have to grovel to my brother Steve, of FieldCraft Fabrications -again, & ask him to copy the pipes in stainless, with larger flanges at the head. It's what I should've done to start with. 
I've also got to take the tank off, drain the fuel & take it over to BKI Welding in Newbury, Berks. They've welded many a fuel tank for me in the past. There's a breather pipe inside the neck of the tank which exits underneath. I didn't want a pipe stub sticking out the bottom of the tank & it's only a breather, so I cut it off flush with the underside. The petrol fumes have got under the edge of the paint though & blistered it. So I'll get a 90 degree stub welded back on so I can attach a breather pipe, running back tight to the underside of the tank. Another self inflicted problem.
Mr Coppersmith's very kindly shortened an old speedo cable for me, (from Loony's Speed Triple), so I can fit that & also connect up the illumination for the new, smaller speedo.
The clutch is dragging, but I'm not entirely sure why. Not just adjustment. I fitted new plates & it's got a new lever & cable. The original Yamaha pushrod, which pushes the plates apart, is in 2 pieces with a ball bearing between the 2. YamBits sell a one piece upgrade, so I might start with that. The only other parts are the worm drive that connects the cable to the pushrod & the springs in the clutch basket.
So, biggest job will be remaking the 'zorsts. Hopefully Steve can do that, partly cos it'd be nice to keep it in the family, but also cos he's bloomin' good at what he does. Once that lot's done, it'll be back to Dslam for another tune up.

[Manky Monkey]

New carburettors ordered & paid for over the phone for collection on my day off later this week. They didn't have any "empty" carb bodies of the right size in stock, but had a pair already made up to suit a BSA Lightning, which they can re-jet to suit. That's the best part of a week's wages gone.