Topic: CB750 F1 Restoration Project - not for the faint hearted

[BeSeeingYou]

Quick query about the rear brake calipers - does anyone know how to get the brake pad pins out?  There seems to be a couple of slots on the other side though I have not tried dig into them and find out if it leads to the other end of the pins.  If it did it would be an easy matter of knocking them out.  I have tried WD40 and 've got good pliers with sharp teeth but nothing is making these move. 

Any help would be much appreciated.

Have you taken the brake pad cover off the top of the caliper?  I believe it is held on by a small hex head bolt next to the bleed screw.  Once that is off you can see two metal clips that hold the pins in.  The pins are tapered on the side facing the wheel and have a slot on that side that the clips lock into.  It was several years ago when I did mine but it came apart easily.

[eddiebpool]

It has been a wee while since I last posted.  I've been busy with life though had a week off last week and spent a bit of time with the bike.

I drained off the old oil and it didn't look too bad.  I sorted out the pump o-rings and replaced the oil filter and o-rings.  I filled up the oil and added some Marvel Mystery Oil which I hope will help clean out any bits of muck that is stuck.  It also helps with oil pressure, supposedly.  I gave it a couple of taps with the starter motor and after a few seconds the oil light went out.  So far so good.

I already had the carbs off and one of the slow jets had snapped off inside.  Carbs 2 and 3 were very badly gummed and I decided that a new rack of carbs was required.  I was able to pick up a very nice set for £102 from eBay.  I stripped, cleaned, and rebuilt using rebuild kits - I wasn't taking any risks.  The previous owner gave me some new parts in the sale which included a new Petcock and new Floats.  The Petcock will go on the tank when I'm finally finished with it and the floats went straight in.  I decided to use cheap pods though only for the build.  I added 115 main jets to compensate for the lean 105 stock and then adding pods.  I plan to put the stock air box on when I'm finally convinced all is well.  I will be putting 110 main jets in at that point.

You can see the short video at https://www.youtube.com/watch?v=uoSuAfAhod4&feature=youtu.be


I got a nice surprise when I turned the engine over and found that I had spark.  I replaced the plugs and caps.  I was planning to the the points and condensors too but it seemed to be working fine for test fire purposes.  I will of course change them.  I manufactured a makeshift petrol tank from a plastic jug and fuel pipe joining tee - seems to do the job and good enough for test fire purposes.  It was very low-tech - the handle of the jug slips over the handlebars and a screwed a self-tapper into the handle to make sure it didn't fall off.

I turned the starter for a couple of seconds and did this 3 or 4 times to make sure I had oil pushed through the engine and that I had pressure.  One last check, and I went for it ...

She didn't start first time - there was a wee cough and a good attempt to start.  Close, but no cigar.  I decided I would try a second time though this time would not use the choke.  She fired right up!  There was a few pops which seemed to come from the pods, no idea what that was going on there.  I'm ashamed to say I couldn't remember where the tickover screw was so stopped the bike and done some exploring.  Second fire ... success again, and I let the bike warm up and I got the tickover sitting nice as 1200.  Very happy 

I have attached a video which is the 3rd fire up.  The bike seems to be running okay.  After a little while I gave it a few gentle rev ups and it was gutsy and responsive.  Now that I have established life I will drain the oil back out and begin the many, many jobs that I have in front of me to put the old girl back on the road.

I notice when I dropped the bike into gear the back wheel immediately jumped to drive and the clutch lever was having no effect.  I need to establish what is happening but I'm assuming the clutch plates are stuck together.  Any other ideas?

One other query, is it better to run the bike for a while on this first batch of oil or simply throw away and start again.  I think the bike has run about 10-15mins total.  I thought I would give it 1/2hr to catch any bits of crud then empty it out.  I'm assuming I'm not doing any harm by running the bike.  I don't plan on doing anything to the engine other than service it properly and I'm reasonably confident it is okay.  The engine has a few noises, nothing too alarming, though I don't know how they are supposed to sound so can't tell if there are any warning signs.

I can have a look at the bike running at https://www.youtube.com/watch?v=uoSuAfAhod4&feature=youtu.be.  I have no video skills so apologies for the poor quality and amateur commentary.  Any thoughts would be much appreciated.

[eddiebpool]

I am looking for a bit of advice about finish.  I've finally started to make some progress with the build.  As I have mentioned before, I'm not taking the engine out the frame, and because of that I'm not getting the frame powdercoated.  I have the front off and will clean, polish, paint and replace as I go.  The headlight / indicator hanger, clocks plate and triple tree were all looking rough so got stripped down / rubbed down and repainted with this stuff:

http://www.amazon.co.uk/Simoniz-Tough-Paint-500ml-Black/dp/B004R95MYE

I like the Simoniz stuff, I don't know if this is a brand that us popular in the US / Canada.  It goes on nice, seems to be a touch finish, but isn't really a Gloss finish as advertised.  I have lacquer though not sure if I should lacquer finish these parts.  This is the stuff I have (I have 6x cans of it so I'm not investing in any other brand!):

http://www.amazon.co.uk/Upol-Power-Clear-Aerosol-500ml/dp/B009G1AU3Q

I am planning to pick my way round the frame too with the Simoniz Tough Paint too.  It would mean I have to lacquer the frame too to make it all match.  I really can't decide if it is a smart idea or not.  I know the purist would say pull the engine and do the job properly.  That's not an option for now.  Any tips from someone who painted frame parts and sundries would be much appreciated.

Unrelated, both my brake calipers were seized and I have managed to get them freed off by the wonder than is a grease gun.  The brakes were the first thing to be removed so I could move the bike around without bursting a blood vessel.  I watched a couple of youtube videos and it looked like it could work.  The hard part was sourcing M10 x 1.25 grease nipples - they seem to be very rare.  This was required for the rear which was the worst of the two.  It worked a treat.  I could not have been more pleased.  The front was a bit trickier until I realised I could attach the same grease nipple to the splitter half way up.  M10 x 1.25 is the standard banjo thread so it works anywhere you take a banjo bolt out of.  I was not sure if the flexible hose would take the pressure, though thankfully the front caliper was not so seized that I couldn't get it moved.  I was replacing the hose anyway so it only needed it to survive long enough to get the piston out.  I soaked the calipers in acetone which helped removed what remained of the paint and I got all the grease out.  I have now stripped and rebuilt the calipers including painting them up.  To keep with the "which paint" theme, here it is:

http://www.amazon.co.uk/Simoniz-Engine-Enamel-Paint-500ml/dp/B00438CDZK

I know it is not specifically for calipers, but it should to the job.  It has a lovely deep gloss finish, it should be tough enough and take the heat too.  The aluminium adjuster arm that site between the front rear part of the front caliper was quite badly pitted so rather than fight with it I elected to paint too with this stuff:

http://www.amazon.co.uk/Autotek-AT0VHTA500-500ml-VHT-Paint/dp/B004ZJIPJA

I bought it originally because I was toying with the idea of painting the engine, after I had removed the horrible paint that was already on it.  The jury it still out on that one, I'm leaning towards "no", at least a "no" for this particular paint product.  It produces a fake looking aluminium finish.  It did the job on the brake part though and it looks okay when matched with the shiny black parts.  I'm not sure I would paint an engine with it though.

Any paint tips very much appreciated.  I have plenty more painting in front of me - frame, metal parts, plastics, and of course the tank! 

[eddiebpool]

To pod or not to pod ...

I put a cheap set of pods on my carbs for test fire purposes in the full knowledge that I was taking the carbs off again to give them a further clean and more thorough bench sync.  They are so much easier to remove without the stock air box that I decided I would ditch the air box all together.  I did a bit of digging and have a solution.  It is not my solution, I found it buried deep online.  K&N (K&N RC-2240) do a 2 + 2 that has an offset on it which allows you to fit 2 of them on a 4 carb set up.  I wasn't sure if the offset would be enough to be a good fit, it is not specifically for the bike.

Carbs centre to centre is 75.8mm.  The K&N filter centre to centre is 76mm.  Near enough.  I tried to use the information on the K&N site to work it out and I knew it would be tight.  I have posted a couple of pics.  As near as I can tell, two of these filters will fit.  I only ordered 1 just in case I had thrown away my money.  I'm ordering the 2nd and will post a pic once I have them on.

A fitting tip - the outermost boot as you are fitting it is more central and therefore get less support.  The fit is tight enough so best to ease the outermost boot on with gentle twisting and a little smear of grease to help it along.  Once you have it seated where you want it - pop the other boot on to the inner carb.  Simple.

I'm hoping that, because these are effectively a shared resource like the stock airbox, it will remove some of the difficulties in tuning.  It may be a significant upgrade, we shall see.

The project rolls on, slowly.  I am going to focus on the engine and frame for the moment (I have it stripped down to frame, engine and centre stand), get that looking nice, then return to the fun stuff and put the bike back together.

[eddiebpool]

Ok, change of plan.  I have done all the hard work to strip so is stems stupid to try to paint the frame round the engine and try to paint and polish the engine in the frame.  The engine is being pulled.  I have it down to the frame and centre stand anyway so not far to go.  I'm going to take the oil filter off, removed the sump and oil pump, and the small cover on the valve cover.  I'm not risking trying to take the exhaust studs out, they look like they will put up a fight and I don't think removal is required (though appreciate the more room I have the better.  I'm looking at the geometry of it and it looks like a small twist (effectively tilting the engine upwards) will take the exhaust studs out the equation.

I was going to try this at the weekend though might have a crack at it one evening this week so I can take the frame and other bits to the powder coat people at the weekend.

Couple of newbie questions:

Is it Ok to sit the engine on the ground if the sump is removed?  Anything I need to know about, such as needing supported in a certain way?

I'm going to lie the bike down on its side to take out the engine.  Again should the engine be supported in some way to facilitate the removal.  I know the points cover is going to take a beating though I'm replacing that anyway.

I haven't decided about an engine teardown, which means I'm going to procrastinate about it then eventually talk myself into it.  I would like to get some fresh rings in because it is likely the old one have a bit of rust (two of the spark plugs were not in the bike when I got it, I have no idea when they were removed).

Any tips would be much appreciated.

[MarshallCS]

Please let me know how that K&N double carb filter works out. It looks like a beautiful part! Great work so far

[calj737]

Just lay some heavy blankets on the ground, right side and lay the motor/frame over onto them. Or, I've seen members use a stack of magazines so there's space between the frame and ground, essentially providing less of a layover distance.

You'd benefit from installing a frame kit to aide with install, removal and top end service. You can choose that now, cut the frame now, and remove the engine quite easily as a result. Member 754 sells them, as well as other sources. Search 750 frame kit.

You could use a pipe cutter with the engine in the bike if you're concerned about taking a saw to it.

[eddiebpool]

Thanks CalJ737, that's exactly what I wanted to know.  I didn't really want to lie the bike over past 90 degrees.  I hope to lift the frame straight up and off.  Shouldn't take too long and I can get the frame away to be made beautiful.

[eddiebpool]

Left work sharp and got the engine out this evening. 

The advice of the old heavy blankets would have been a good one if I had any.  Long story short, I recently moved home which finally gave me the space to have a project.  The problem is that typically when you move home you throw out all the old stuff.  However, when you move you usually have lots of cardboard - which I kept.  I put a big stack of cardboard to the right of the engine, tipped it over, struggled a little, then found my solution.  It wasn't so difficult.  I realised the engine wasn't sitting right to remove the frame and it was fighting against me.  I put a short piece of 2x4 under the cylinder head, and the same under the clutch cover.  The leveled the engine to 90 degrees from upright.  The frame lifted off really sweet after that.

I removed the oil pump from underneath.  There is no metal in the sump but there was a couple of leafs of black plastic, looked like flakes of paint about the size of a dime though they were thicker and they bend rather than crumble.  Any ideas?  I tried to think of what plastic parts there may be inside the engine.  Cam chain guide?  I don't know what it is made of and can't think of anything else.

Anyway, job done for now.  The frame will get a quick once over to make sure I have everything off that needs off, then it is going to the powder coaters later in the week.  It will take a couple of weeks (the company is busy, which I like - it means they are probably good) but plenty of other jobs to be done in the meantime. 

[calj737]

If it is plastic. Likely the tensioner as you suspect. This is a great time to consider tapered steering bearings before powder coating, and renewed swing arm bushings.

[SOHC4 Cafe Racer Fan]

Left work sharp and got the engine out this evening. 

The advice of the old heavy blankets would have been a good one if I had any.  Long story short, I recently moved home which finally gave me the space to have a project.  The problem is that typically when you move home you throw out all the old stuff.  However, when you move you usually have lots of cardboard - which I kept.  I put a big stack of cardboard to the right of the engine, tipped it over, struggled a little, then found my solution.  It wasn't so difficult.  I realised the engine wasn't sitting right to remove the frame and it was fighting against me.  I put a short piece of 2x4 under the cylinder head, and the same under the clutch cover.  The leveled the engine to 90 degrees from upright.  The frame lifted off really sweet after that.

I removed the oil pump from underneath.  There is no metal in the sump but there was a couple of leafs of black plastic, looked like flakes of paint about the size of a dime though they were thicker and they bend rather than crumble.  Any ideas?  I tried to think of what plastic parts there may be inside the engine.  Cam chain guide?  I don't know what it is made of and can't think of anything else.

Anyway, job done for now.  The frame will get a quick once over to make sure I have everything off that needs off, then it is going to the powder coaters later in the week.  It will take a couple of weeks (the company is busy, which I like - it means they are probably good) but plenty of other jobs to be done in the meantime. 

Well freakin' done!!

Next time (when you re-install the engine), hopefully you will have a frame kit installed.  If not, remove the oil filter, breather cover and sump to ease installation. 

[eddiebpool]

Quick query:

I have stripped the forks down and notice that the two fork springs are slightly different lengths - about 6/7mm of a different (1/4 inch).  Is this an issue?  I should have measured the full length rather than just the difference, that might have been more helpful.  I will do so when I get the chance. 

If anyone has an idea what the minimum length should be, and if the difference is an issue, that would be much appreciated.

[SOHC4 Cafe Racer Fan]

They should be equal length but 40 years of wear and sitting takes its toll. Not a bad idea to get a new pair sprung for your weight.

[eddiebpool]

Problems, problems.

I started a top end strip down this weekend and run into problems with the crappy cross head screws at the the top.  Two snapped when I tried to remove them with the impact screwdriver.  One was not such an issue, it snapped near the top and wasn't and issue beyond that.  The other screw was a nightmare.

I don't know if anyone has come across the same issue, but there seems to be compacted white stuff (assume oxydised aluminium) all the way down the valve cover.  With alot of jamming of screwdrivers I was able to get enough gap to get a hacksaw blade on it and remove it.  I had a spare valve cover that I bought to practice my polishing skills on, so was not worried about that part.  I hoped I would get the remainder out the cylinder head with my screw extractors, but no luck.  I am trying to decide if the answer is left hand drill bit or go the whole hog and helicoil.  I haven't done a helicoil before but it looks easy enough. Any suggestions?

As you can see from the pic, I have damaged the casing.  I'm hoping a bit of liquid gasket will fill the gap.  I am more worried about that than the broken screw which I know can be fixed.  I can get another cylinder head, but I hope I don't have to.   

The cam chain tensioner was stuck with lying around so long but I soon got that freed off.  The engine is lovely.  The valves look good, the cylinders are smooth and unmarked and the piston look spot on (clean with a dusting of dark brown on top).  I was very happy.  Until ...

I can't get the jugs off.  I have rapped them in every direction with the rubber mallet.  There looks to be a couple of stronger points to get leverage on but I don't know how "enthusiastic" I can be before damage is done.

[calj737]

You've been too enthusiastic already with the screw removal. Left hand bit after letting it soak awhile in penetrating oil. Then, also try some directed heat before the left hand bit.

I am very leery of liquid gasket as a remedy of those gouges. I'd prefer to TIG weld and machine it smooth again, if it were me.

A trick for lifting the jugs is to re-install the 4 bolts at center of head back into jugs. Stuff small diameter cordage into the cylinders, then manual rotate the crank. The pressure from compressing the rope with the pistons drives the head up and takes the jugs with it. ONLY use the left side rotor bolt to do this. The right side points bolt is NOT strong enough.

[eddiebpool]

Thanks Calj737, I hadn't thought about applying the pressure from the inside and I like the idea.  Do you put the rope in all cylinders so you get an even lift, or just one (1 or 4) to apply the pressure in one place.  I can see the merit of both though don't know what the dangers might be.  Also which way would I turn the nut?  Sorry for the newbie question, I'm learning as I go.

I agree on the TIG weld.  I don't want the joint to fail and them have to strip everything down again.  A permanent fix is what I'm looking for.  I have emailed the picture to a couple of local companies and see what they come back with.  I have not welding skills or equipment, leave that to the professionals.

[calj737]

Stuff all 4 cylinders. Direction of rotation won't matter, but anti-clockwise on the left should be easier.

[eddiebpool]

I have a 600mm breaker bar so can get plenty of grunt on the nut.  Is there a limit on how much force I should apply?  I should add that I'm a big guy, over 300lb, and am not short on strength.

[calj737]

Well, Gulliver, settle down a wee bit. Understand turning the alternator bolt left hand will ultimately loosen it. Only needs a few good nudges. You're not trying to wrest the rock of Gibraltar free from it's foundation.

Prepare the base of the jugs with some penetrating oil in advance. Should come up with decent shoves, but won't require your hateful 300# Mr Hyde 

[eddiebpool]

Success!  I took a chance of K&N twin filters after reading something online.  I did the sums and it was close, and it certainly was.  I have got both filters on and there is barely 1mm a gap.  The most important thing is that they fit.  I haven't tested how the bike runs, and to be honest I wouldn't know if it was better than stock because I have no previous experience.  I would be surprised if it is not an upgrade though on that horrible stock air box.  I hope it has the advantage over pods by being, like the stock air box, a shared resource.  I have increased the main jet to 115 to utilise the better air flow.  I'm excited about this.

I haven't put the clamps on one set of clamps because they arrived buckled and wouldn't work with what is already a tight fit.  It definitely fits though.  As I mentioned previously, the trick is to use a smear of grease, work on the outside carb first (1 or 4), then once you have it where you want it, pop on the other boot.

Very pleased, should work well and looks lovely! 

[eddiebpool]

That's how tight it is!  Meant to add - this is the product - http://www.amazon.com/RC-2240-Performance-Universal-Clamp-Chrome/dp/B00062YOK4

[eddiebpool]

I haven't posted for a while, life gets in the way of the project.  However, a big thanks to calj737 for the advice on stuffing the cylinders with rope.  It didn't quite do the job on its own.  I did are instructed, got some good tension of it.  I picked a bit of gasket out with a thin blade at the back right corner (to the left of the points cover as you look at it from that side".  I got a small chisel into the gap and gave it a few good taps.  The gasket soon gave up the fight, with just a very small nick out the aluminium to show for it.  Job done.

Quick query:

I want to get the frame and frame parts powder coated but I cannot get the pin out the main stand.  I have tried battering it, electrolysis bath, WD40, I'm thinking I might have to buy another stand and give up.  Any ideas?

[calj737]

It's stuck due to corrosion. Heat it with a torch, then use a mallet and a socket the same OD as the pin and drive it out. Once it starts, it will "break loose". Heat, penetrating oil, and a mallet. Sure fire recipe!

[eddiebpool]

It has been a wee while since I last posted though have had no chance to get to it.  I am about to move jobs and, as typical in my industry, I was immediately put on gardening leave.  6wks of enforced house arrest and the bike project resumes!

I have finally split the cases.  The engine was covered in a horrible paint that had a slightly hammer beaten look to it. Nitromors couldn't touch the stuff and I was worried about what strength of paint stripper I would need.  I tried a cheap stuff from Screwfix.  It is like a lotion, doesn't dry and stays like that overnight.  You just slap in on thick, give it another once over after an hour or so, then walk away and let it do its thing.  It is slow acting - overnight is good if the paint is stubborn and on thick.  That horrible paint just curled up and died.  I have attached pics including some details of the product.  It is really nice stuff to use, doesn't smell, won't burn your skin or eat your clothes.  Someone may know the equivalent product in whatever country though I would recommend UK folks to give this a try.  It is cheap, and it works.

I sent a pile of stuff to the powdercoaters including frame, swing arm, battery box and the other electics bracket that attaches to that, triple clamps, headlight bracket, brake stay, seat hinges, basically everything that would have been nice and black out the factory but isn't any more.  I will post more pics when the parts come back.

I intend to have a busy time on the bike in the coming weeks.  I want to get all the old fixings replated.  It may sound silly, but what do I ask for when getting a quote.  Is it zinc plating, or something else?  I want to get the bigger stuff like axle bolts done too though wasn't sure if they would have been zinc plated originally?

As ever, any help or advice much appreciate.

[jaguar]

Nice to see the early F bikes getting some love.
Would like to have a clean stock one some day.

My CR project is based off one.