That Montjuic of mine

I’d take them off on a track but on the road I like knowing what’s behind me :D
 
So it’s back to the Montjuic and sorting out the crud in tank issue.

When I left it I’d filled the tank with cheap fizzy drink, left it a week then emptied it and rinsed it with Xylene. Well that didn’t remove the overspray on the spine of the tank inside the filler cap so I put it back on the bike and left it to work on my Norton.

While that was going on I ordered a cheap shot blaster that just connects to my compressor and you poke a steel tube plus flexible pipe into a tub of 80-120 aluminium oxide media.

I drained the Xylene out this morning, left the tank on an outside table in the hope that it would dry out (it didn’t) then put it on a plastic bucket with the fuel taps removed, cranked the compressor up to 6 bar and had a go. Two minutes later the overspray was gone and the area in question looked spotless.

I ran a hosepipe through to get rid of the media and once the water was running clear I put the taps back on, poured 1 litre of 80% phosphoric acid in, topped it up and it’s now in a cradle hopefully cleaning itself.

I’ll give it a week, drain it, rinse it with diesel, swill a litre of unleaded around in there then fill it with super unleaded and throw some sparks into it then review the situation.

The bike is back on the Abba Skylift in my workshop and I’m seriously considering a top end overhaul. Both the head and base gaskets weep a little bit and I’ve no doubt it would benefit from a new camchain plus, assuming I can get them, valve stem seals.

The wheels are coming out to have new bearings fitted then be painted and the discs need a bit of a clean then paint the centres black.

Someone put me off before I waste hours trying to get a gasket set 😀
 
I’ve now removed the wheels, removed bearings, spacers and shims with a fair degree of heat and a decent sized slide hammer and they’re ready to go for painting.

I’ve got a contact who may be happy to do them so I’ll throw them in my van and go to see him tomorrow, at the moment he’s keeping busy by helping out at his dads tyre and exhaust business so should welcome the work.

Once the calipers were off the wheels were still a bit tight when rotating them by hand and when I stripped the bearing out it became apparent that damp had got into the wheels one way or another and new bearings will certainly improve things.

This is what I found when I got everything apart

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I’ve cleaned everything up with Scotchbrite pads in my Dremel and I had new bearings in a box waiting to go in the spare wheels so as soon I can get the wheels back they can go straight back in. I fitted new brake pads a while ago but the calipers could do with servicing so I’ll see if I can get service kits for them.
 
That’s a good start, now go and find me a new camchain so I can change it whether it needs it or not :D

I’m sure there’ll be someone who can supply me with the correct spec chain and a soft link, probably all I’d need to do is count the links and get it ordered. I’ve got a full set of valve guides that someone sold me when he decided against changing them because he couldn’t get seals but there’ll be someone who can source a seal that would do the job, something in the back of my mind is telling me that a certain year Honda CBR600 valve stem seals fitted if you modify the guides slightly but that needs some research.

The wheels are going to take about a fortnight to strip, clean, paint, lacquer then refit the tyres and balance the wheels. I know I should put new tyres on it but for now the old ones will be fine for what I’m doing at the moment so the next step is to have a look at making an engine support so I can clamp it to work on it. I’m not taking the engine out until I know I can get everything I need because it’s just piss me off if I have to bung it back only half done.
 
Today it’s back to being that fucking Monty!

I drained the phosphoric acid solution out of the tank then flushed it a load of times until no more blast medium was coming out, filled the tank with unleaded, put it on the bike and turned the fuel taps on. The fucking floats weren’t shutting off the fuel flow and it pissed petrol everywhere from both carbs :blast

I’ve now removed the tank and carbs, stripped them and I’m going to buy another ultrasonic cleaner and do them again. The seats for the needle valves don’t look as clean as they should and I suspect part of that is because I didn’t put a light coating of WD40 in the carbs after cleaning them last time -lis because I’m a lazy bastard I didn’t completely remove the needle valves when I dropped the carbs in the old cleaner before it went tits up.

It’ll be fine once I’ve got the floats functioning as Mr Dellorto intended and once it’s running I’ll make a final call on the top end rebuild question :D
 
I’ve given it the big “fuck you!” and the engine is coming out in the morning :D

The needle valves work perfectly but in the end I decided that I know it wants the top end sorting out and the more I keep pretending it doesn’t the more I’ll stare at it and mutter about doing it eventually so I’ve cleared the decks, put a shiny new bench in the workshop and started to strip the bike.

The exhaust system is off so I’ll give it a new coat of matt black Sperex because they’re stupidly expensive even for rotten ones and this is a good one. I’ll drain the oil tomorrow, remove the alternator leads and get the engine on the bench to give it a good dose of looking at :okay

I’ll bung photos up to keep everyone amused as the job goes on and you can place bets as to how long it takes, how many bits I can’t get and how much the job costs me in GBP.
 
I’ve not even unlocked the workshop and it’s costing me money because it’s years since I rebuilt a top end so I needed a piston ring compressor and a new valve spring compressor. I used to do piston rings with a very basic clamp I made when I was an apprentice so fuck knows where that is and my spring compressor is at least 40 years old and just needed replacing.

Add on valve lapping paste and gasket sealant (oil return blocker) ordered today and my shopping bill was well over £100.

I’ll order valve guide seals later when I’ve checked sizes to make sure I’m getting the right ones and at some point once the barrels are off I’ll check the bores before ordering pistons. If the bores and ring gaps are good I’ll probably just hone the bores to remove any glaze and hopefully bump up the cylinder PSI a bit. I’ve got new valve guides already so I reckon that if I don’t need new pistons it’ll cost me about £250, double that plus a bit if I fit new pistons and rings. If it needs a full top end including rebore, new valve seats etc then it’ll be a grand :blast
 
I’ve not even unlocked the workshop and it’s costing me money because it’s years since I rebuilt a top end so I needed a piston ring compressor and a new valve spring compressor. I used to do piston rings with a very basic clamp I made when I was an apprentice so fuck knows where that is and my spring compressor is at least 40 years old and just needed replacing.

..........t

Awwww, it's only a twin, hands (several pairs :D) or cable ties will be fine :)

Andres
 
Awwww, it's only a twin, hands (several pairs :D) or cable ties will be fine :)

Andres

I used to use plastic shim and cable ties but I’m not working so have to pay for my own shim and a ring compressor is the same price. I can almost certainly pop the collets on the valves with a wooden mallet but getting them back in a controlled manner isn’t as easy :D

My wife pointed out earlier that if I was being honest with myself I’d include the cost of new flooring and bench for the workshop in the price so I told her to fuck off :rob
 
I used to use plastic shim and cable ties but I’m not working so have to pay for my own shim and a ring compressor is the same price. I can almost certainly pop the collets on the valves with a wooden mallet but getting them back in a controlled manner isn’t as easy :D

My wife pointed out earlier that if I was being honest with myself I’d include the cost of new flooring and bench for the workshop in the price so I told her to fuck off :rob

It's what money is for, JFDI :D

Andres
 
That’s it, the engine is on the bench and ready for the big boys work but, as promised, you get picture.

Here it is with the wheels out (they’re away being refurbished) and just about ready to start.

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Because it’s a shit bike you have to get the exhaust system off but that’s only a case of undo the clamps to the cylinder head then two at the back and two holding the down tubes to the collector. I’ll be gobbing a new coat of Sperex on these in due course.

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Drain the oil, clean the filter and put it back because I don’t want it dribbling like an incontinent GS owner. I junked the original nuts and split washers in favour of stainless shakeproof nuts because I’ve got them so I’ll use them.

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Next was remove all the bolts and engine plates bunging them in the ultrasonic cleaner filled with a mixture of degreaser and water. It’s always nice when the come out easily because that usually means the frame is straight and you never know what’s happened previously with a 40 year old bike.

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Engine out and on the floor.

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And finally on the bench and firmly ratchet strapped down. Edit: I’ve just noticed that I’ve shaken then supports out of the bench. Piece of shit! I’ll bung them back before the top sags.

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I wouldn’t say I’m in the slightest bit anal but I like to know what I’m throwing in boxes.

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that’s it for now. I might take the mighty Husqvarna out for a rip this afternoon but because I’m a dick I’ll probably go back to the engine :blast
 
It’s confirmed, I’m a dick.

I went back to the engine and stripped the top end. It shouldn’t take that long to strip the top end but the head was a shit to get off and basically I had to fight it all the way up the studs.

The cams are a bit odd, I’d say one’s a genuine S1 and I think the other one is a re-profile because the stamping is different and it’s also got Joy Eng. etched on the side of one lobe. I’m ok with that because Joy always had a good reputation for their camshaft work and if one of the originals was showing wear on the lobes so got replaced then so be it.

First shot is the cams still in position.

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Cam buckets and bearing caps. I’ll buy new needle roller bearings because they’ll be cheap enough and while it’s apart it’s stupid not to.

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Once I’d got the head and barrel off I had a look at the pistons and to be honest, they don’t look as if they’ve got 25k miles on them. They’re a bit sooty but the outside diameter of the pistons have no burn marks on them so no oil has been getting past and leaving crap on them.

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The valves look very black as if it’s either been running super rich or burning oil. When you look in the ports the RH exhaust valves have oil on the stems with more on the outer one plus there’s oil in the port. That’ll be the valve guide seals then.

Another pointer towards the head having been off and the issue being failed seals is that the combustion chamber is cleaner with no soot on the inlet side.

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Anyway, it’s all apart, I’ll order seals and think about a rebore. I’d say it’s right at the top limit before needing a rebore because front to back the bores are +0.12mm and left to right they’re +0.05mm

I’m going to struggle sourcing high compression pistons, I can get Alpino ones for about £300 then pay for a rebore. If I put standard compression pistons in then that absolutely rules out racing it but it’d probably make it more reliable. What do I want? I don’t fucking know! :nenau

I know it’s purely a guess but I think it’s been put back together with the old valve guide seals because they were unavailable for a long time but now I can get them.

The question is whether to flick a hone through the bores and take out any marks plus cross hatching will make the rings seat better even if there’s excessive clearance or rebore with lower compression pistons and probably get increased reliability.

Either way I’ll fit the new guides and seals then lap the valves in give the ports a bit of a polish.

This is where we’re at right now with the engine and I’m currently necking a pint of Otter Ale :beer:

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Next job is to strip and service the brake calipers while I wait for seals and a gasket set plus maybe a rebore.
 
A very productive afternoon there Andy...........you deserve a beer:beerjug:

But you are a Dick:D

I know nothing about these engines, but I’m looking at the cam retainers or I think you called them buckets. The numbering of them puzzles me and are there two missing?:nenau

Edit...... I understand now...:thumb ( I’m a dick as well):blast
 
It’s always nice when there’s more than one around :D

I’ve found a set of new 0.5mm oversized 10.2:1 F500 pistons which come with rings, pins and circlips for £400 plus whatever import taxes I have to pay but they’re actually a bargain because stock 9:1 pistons without pins and clips are only £100 cheaper so it’s a false economy to buy the cheap one :augie

I really want to get the head stripped before I order engine parts because they’ve got to come from Australia so there’s no point in spending extra postage. I just need to check the valve seats and make sure the seals for the guides are 100% correct then pull the pin.

It’s going to cost a grand which is a lot to spend but it might motivate me to ride the fucking thing and if I don’t want to keep it having the receipts for a full top end rebuild will pay dividends if I sell it.

Anyway, brakes tomorrow. That’ll be fun because the first thing to do bung extra brake fluid in to get the pistons out a bit further to check what they’re like behind the seals so I’ve got a better idea of what’s facing me.
 


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