RobbieRobot Cafe Racer Project in pictures

You are thinking along the same lines as me

 

I parked here and went to get an ice cream. As I walked back I noticed a crowd had gathered around the bike. One guy said it's nice to see something original for a change.

 

I dug out the original seat strap and cleaned it up.

 

It looked to be the exact length without needing modification.

 

So, in time-honoured tradition, I made a template for the mounting plates.

 

Then fabbed and fitted the plates and fitted the strap.

 

I also added extra foam under the lip of the seat where it abuts the tank and after fitting the strap if feels like the seat won't ride under the tank as it was tending to do during today's ride out. Incidentally I covered about 60 miles today and I was pleasantly surprised with how the engine ran with the pod filters still with standard jetting. No bogging or hesitancy and clean revving. A plug chop indicated all was well being straw coloured.

 

Beautiful bike man.

 

Thankyou.

 

what exhaust is that? I am in need of a 4-1. Sorry I'm too lazy to go through the awesomeness of this thread to find out

 

The exhaust is a Motad stainless steel 4 into 1.

 

Parts removed and sandblasted prior to zinc electroplating.

 

Parts back from zinc electroplating. A big thank you to Alan Hastings and all at Hastings Metal Finishers Ltd, Hebburn, Tyne and Wear for such a good job.

 

Wow. Just when I think you've done everything possible for this build, you show me how you take it to the next level and beyond. Truly inspirational.

 

Thanks for the compliments. This is an obsession, remember!

 

Today I put some miles on the clock, about 120 in all. Starting with a ride to my brother's house (pictured) then onwards around the roads of North Yorkshire. I stopped off at a small motorcycle dealers about 3 miles from where I live. The reason I went there is because when I bought the bike it had the name 'Clarkes Motorcycles' on the registration plate. Anyway, I walked in and said 'I have a 32yr old bike parked outside and I think you supplied it from new'. The guy came out and was pretty surprised with what he saw. After a bit of discussion he went back in, disappeared out back then returned with a dusty book that was used to record sales. After a couple of minutes he found it. Supplied to him by Mitsui Yamaha for £1500 and sold to a Mr. Thompson on 12th October 1982 for £1800 brand new, there it was in black and white. We both said WOW! He was then quick to point out it was out of warranty ha ha..

 

All set to press on.

 

Here's a shot of the bike parked at Easby Abbey, near Richmond. The route from my house to here includes some of my favorite roads and was also the route to work about ten years ago when I had my FireBlade. I became so used to the roads to the point where I was capable of, well lets just say, getting to work very, very quickly indeed. Today en-route I saw the ton up on the clock which is of course a prerequisite for any self respecting Café Racer. Another box ticked.

 

I was very pleased with, and quite surprised at the rideability and performance of the bike today. Despite having pod filters (attached to the standard intake rubbers) and still on standard jetting, there is nothing lacking in any area of performance other than a reluctance to go much further than the ton at the top end. No bogging or hesitancy anywhere in the range. I would be reluctant to start changing the jetting now. Next time out I plan to do a high speed plug chop just to check it's not too lean in the upper rev range.

 

This is the result of the plug chop after hitting the kill switch whilst accelerating hard in third gear at over 7000 rpm with the engine fully warmed up having just synced the carbs and setting the pilot mixture screws to obtain a yellow colour coming just off blue using a Colortune. I've done another 80 miles today and the bike is still performing really well with the pod filters still on standard jets. I really was expecting all sorts of problems getting the pod filters to work right and I even had a contingency plan to refit the air box albeit in a modified state. But I am now a little baffled as to why the bike should be working so well after all the previous problems that I've read about on this site. The colour of the plug was the same on all four, light brown, and is an indication that the fuel/air mixture is good. Could it be simply down to the fact that I've fitted the pod filters onto the standard intake rubbers I wonder?

 

OUTSTANDING!!! You, sir, are a master.

 

Quite possibly. The only other genuine success story with pods that I'm familiar with was done the same way.

 

did you only pull one plug? what cylinder? I have read that the outer cylinders will suffer because of wind turbulence that the inner carbs are not subjected to.

CN

 

nice work Robbie,
can you tell me where you got the colourtune plug from to fit the 12mm plugs, or is the 650 a different size than the 600.
I have a colourtune but the plug is too big
cheers,
stu :?

 

Thanks for the sentiment but I really don't think so. All I've done is to follow Rick's carb cleaning and setting-up advice to the letter. The fact that the pod filters seem to be working is not due to anything I have done in particular.

 

did you only pull one plug? what cylinder? I have read that the outer cylinders will suffer because of wind turbulence that the inner carbs are not subjected to.

CN[/quote]

I pulled the two outer plugs first, did another run then pulled all four. Same result as the photo each time.

 

The 650 has 14mm plugs Stu. I got the Colortune off eBay for £24.99.

 

I just bought another part bike. Another xj650 4k0 non-yics. The eBay purchase consists of the engine, frame, forks, wheels, swing arm and drive train and tank. No loom, clocks, seat etc or registration documents. The guy said it spins ok off the starter motor and has 120 psi compression in each cylinder. This could mean mark11.

 

The guy delivered my latest acquisition this afternoon. Here are a couple of pics. So far I've removed the carb rack and checked the valve clearances which were all in spec except for one of the exhaust valves which was 0.025mm too wide. I've noticed that the when I removed the oil filler cap there was a smell similar to paint brush cleaner. I'm assuming fuel must have seeped into the crankcase at some point as is the tendency of these bikes when the float needles require attention. I intend doing a compression test on all cylinders tomorrow when my spare car battery has charged overnight. The forks appear to differ from my other bikes having what look like valves in the top. I am hoping to resurrect the engine for use as a spare or possibly use it in a second project bike. Generally, on initial inspection the unit looks serviceable and the cam lobes look to be in good condition if a little gummed-up. Time will tell if she ever runs again.

 

Yesterday I had a 100 mile ride out in North Yorkshire, stopping off at Helmsley where several other motorcycle enthusiasts showed a lot of interest in the bike. The bike had been running well until no2 spark plug was fired out of the head at about half way distance. It wasn't really a surprise when it happened. I was aware the threads were damaged and having done a couple of plug chops the other day I realized it would only be a matter of time. Meanwhile I had begun to recondition a spare head that I bought on eBay a couple of months ago. I decided to dismantle and sandblast the spare head then thoroughly wash the head in an industrial washing machine twice. Next step is to repair a broken header stud that the PO has tried to drill out and has drifted off centre. Then lap the valves, re-paint then set the valve clearances. I have ordered a spark plug thread repair kit and intend to attempt a repair with the head in-situ first.

 

Spare head prior to sandblasting.

 

Spare head after sandblasting.

 

i don't know how bad this is but i wish you wouldn't have done it

 

yeah, that's no bueno. if it had been me, I would have opted for chemical stripping instead of blasting. if I did feel the need to blast it, I would have it soda blasted.

CN

 

The process used is tried and tested. The equipment used has a fully adjustable degree of abrasion and was set relatively low. The detail you have highlighted is where an indirect stream of media has barely taken the glaze off the valve bucket bore. There are several guys that I work with who are into classic bike restoration, one in particular, Dave, has restored two Kawasaki Z1s. I regard him as a genius. He is the one who guided me on the use of the media blasting machine and has carried out exactly the same process on his restorations as I did successfully on the carbs of my café racer. Here is a pic of Dave's work. The main concern with this process is that all of the blast media is removed. This is something that I will ensure will be done. Please don't confuse this process with some other blasting processes that can literally rip duralumin to shreds.

 

Well if it's ok with Dave it's ok with me

 

Good news regarding the stripped spark plug thread. I ordered a spark plug thread repair kit off eBay.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 1420677579

It arrived yesterday lunch time. Job completed within an hour and managed a 50 mile ride to check it out. It would be rude not to take advantage of this unseasonably warm, sunny weather. Bike performed good as new.

 

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It arrived yesterday lunch time. Job completed within an hour
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so, how do you stop the "bits" from dropping into the cylinder,
or fish them out after?
stu :?

 

You can't, that worried me too when I saw it done but a blast of air removes all the swarf back through the plug hole

 

I grease my tap (fill the flutes) to catch all the metal chips. it works a treat!

CN

 

Hi Stu. I had my reservations about this kind of repair but after watching this vid

http://www.youtube.com/watch?v=Cqid0tfLzEg

I felt more confident. Having said that I did improvise a little. First of all I set the piston about half way up on it's compression stroke. This ensures both valves are closed so that swarf can't get trapped behind the seat. Next I pushed an industrial wipe (a square sheet of clean white cloth) into the plug hole and pulled it back to a point just below the bottom of the thread with some pointy nose pliers. I then started tapping the thread with the reamer/tap supplied in the kit. I used a vacuum cleaner at frequent intervals to clear the swarf as it was produced. This ensured minimal swarf entry into the cylinder. I used WD40 to lubricate the tap rather than grease as I didn't want a lump of swarf laden grease dropping into the cylinder. This would be very difficult to suck or blow out. After the new thread had been cut I pulled the cloth out with the pointy pliers, making sure it had all come out. I then taped about an eight inch length of rubber fuel line to the nozzle of my vacuum cleaner. I tested it's ability to pick up a largish piece of swarf - and it did. I then proceeded to suck out the remaining swarf from inside the cylinder. Finally, I blew out the cylinder with compressed air although I wasn't aware that there was even any left at this stage. That only left the insert to be fitted to the spark plug, smeared with thread locking compound and screwed into the new thread. It worked reasonably well although the new thread wasn't the best I've ever produced. The main thing is that the spark plug tightened up firmly and the bike ran well afterwards. I'm still working on my spare head just in case.

 

My spare head had a broken header stud that the PO has tried to drill out but his poor workmanship had caused the hole to drift off centre. I rigged up my electric drill and stand and clamped it to the bench above the vice with the head securely fastened at the correct angle. Using a tri-cut slot drill I produced a new, larger hole roughly in the centre of the cast boss. I then tapped the hole and screwed a length of stud into the tapped hole. I then cut the stud off and ground the excess back so that it was flush with the original cast face. All that's required now is to drill and tap a hole for the new stud.

 

After centre punching the position of the new hole I drilled it deep enough to pass right through the repair plug (which was 10mm long) and a further 10mm into the parent metal of the cylinder head.

 

Next step, tap the M6 thread 20mm deep from top face.

 

New, longer stud purchased here

http://www.ebay.co.uk/itm/191085831960? ... 1439.l2649

screwed home 20mm deep. The new stud is threaded through the repair plug and into the cylinder head meaning there is less risk of the repair plug working loose.

 

Valve lapping in progress.