June 2013

The pipes are ready !

I ordered some exhausts a good while back from Kenny at TSA (two stroke addicts), he advised me of a 10-12 week lead time so I bit the bullet and slapped a deposit down.

I managed to get back from Holiday and go and collect them from him personally. Kenny designs and builds YPVS expansion chambers and on the UK forums the opinion is that he makes the best pipes available. Lots of midrange power which is perfect for the road. Kenny gave me lots of useful info and suggested a good carb jetting base to start from, shame I’ll not hear the pipes until the bike is finished. What struck me is the quality of workmanship, they are also very lightweight. The end cans I went for were alloy and they weigh more then the expansion chambers !!!



May 2013

Once again little garage time this month but I have managed to get these parts vapour blasted and repainted. I used RD Cox and Sons in Reading and they did a great job.

From this…..


To this


Between the Vapour Blasting and painting the barrels were sent of to Granby Motors in Liverpool for a rebore. They bored them and supplied Mikita pistons to suit and did a very fast turnaround of 4 days. The crankcases as originally supplied from Yamaha would have been bare alloy for the lower half and painted satin black for the upper half. The Vapour blasters said they could do a satin finished alloy which looks like its been painted silver, yet it is bare metal. The finish is superb and should be easy to keep clean.

Only trouble is now everything I put back on the bike will have to be re-finished to the same high standard otherwise it’ll look shabby.

I did spend a few evening on the web ordering various parts for the rebuild, as it looks like I’ll be gathering parts for a Winter re-build. All hopes of getting the bike finished for this summer or year look doubtful due to holidays and a promise of doing some dreaded DIY in my house.

April 2013

Been a while since the last update…… But in my defence the garage is too cold over Winter!

I have completely stripped the bike and made a start on cleaning and preparing for paint etc.
The frame was filthy and a bit rusty in places but not structural so along with the swing arm and various brackets, was dropped off at Power Park Autos in Banbury. They did a great job and I have a very deep gloss red on the frame, swing arm is silver and the fairing brackets and stands were welded and coated in gloss black.


I’ve been through numerous wire wheels cleaning up bolts, swing arm links, brackets etc. I have bought a zinc plating kit from Gateros and intend to have a mass plating session when all the steel parts are prepared.

The Tank and plastics have been sent to Power Park Autos for strip and paint. They have done a brilliant job, using the correct pearl/metallic white and red.
I got some graphics from RD LC CRAZY and applied them before the top clearcoat. But I was not happy with them, I got the fairing and belly pan ones on poorly, so ordered some replacement ones. Fitted them and though not 100% happy due to bubbles etc decided to go with it. Left the tank etc in the spare room and a week later orange blotches appeared all over the white paintwork!!! Took it back to the painters and went on holiday.

The painter said there had been a reaction between the processes, so removed everything and started again. I now left it for a few weeks to check it would be Ok this time before wasting more graphics.

I decided to make my own graphics as I am in the print trade as a hardware engineer for Canon. So many many hours making templates and using Adobe illustrator I ended up with my own set printed on quality Vynil.


I drank 2 strong bottles of beer on a Friday evening and sat down to apply them, I had printed a few sets so I could afford to get them perfect. I was well pleased with the results, nice flat bubble free graphics.
Sent them off for the clearcoat and got them back and the final result is brilliant, probably better than factory.

September 2012: Frustration !!!!!

The first test ride after the Olympic fornight spannering sessions went really well. The bike started up and ran on both cylinders, the clutch did not slip and the brakes were much improved. I was very happy, job done !

Later that week I decided to take it out for an after work ride. Damm thing took over half an hour to start and would not run on both cylinders all the time. When I rode it at high speeds it kept cutting out and would not start again without lots of swearing and kicking (by me). Back in the garage, carbs off revealed dirt in them. Despite having a fuel filter some fine particles were getting in to the floatbowls. Looks like the rusty tank needs sealing. Checking the plugs for sparks showed a weak orange spark so maybe I had an electrical problem too. It would be difficult to find out what was causing it without spare parts to swap out and test. I checked out all the connections and measured all the resistances of the coils etc. Everything was as the manual says it should be. I sourced a complete igintion system from a later bike. The CDI unit I had was well known for breaking down after about 10 mins running, so the later unit would be more reliable in the long run. I needed to modify the wiring loom to fit the CDI as the wire connections and colours were different. Now I had a much better spark, a fat blue spark and the engine starts easier.

However the bike still has problems, when I ride gently and don’t use full throttle everything is fine, but as soon as i give it a long burst of wide open throttle (like acclerating quickly through the gears) the engine dies on the right cylinder again. Its like fuiel starvation, but even running with the fuel tap on prime to give a good flow it made no difference. Very frustrating and despite several carb/electrical strips and checks I still can’t get it right. My thinking is that I have a bad crankseal that leaks air and weakens the mixture. Looks like an engine strip to replace that, so time to SORN the bike and start the resto.

August 2012 : Clutch and Brakes

There was still some summer days left before the tax ran out so I decided to address the important things so I could ride the bike before the winter strip down. My other half was watching all the TV coverage of the Olympics so I could spend 2 weeks of evenings in the Garage.

The clutch needed attention and the front brakes were pretty poor and I still had trouble starting the engine, it was never going to be plain sailing with a 30 year old bike.

The clutch would be an easy fix, new friction and plain plates with new springs would see it sorted. The clutch casing paint had flaked off and was in urgent need of some Pj1 paint. Most Jap bikes used to have pozidrive screws holding everything together, only trouble is that they made them from soft cheese ! But I was lucky and only had to get the hammer and drift out for 2 of them. They won’t be going back in anyway as I will use hex head allen screws. Draining the oil, showed some contamination so maybe this might be helping the clutch to slip. I stripped off all the paint from the clutch casing using nitromors paint stripper and wire wool. Heated it up with a hot air gun and then sprayed it with Pj1 Satin Black. Looked good and i was well pleased as no runs or drips. This took nearly a whole week of evenings and next time I will send it to be vapour-blasted.

The front calipers had been “repaired” before as the pad retaining pins had stripped the threads so a large bolt was used in a re-threaded enlarged hole. Not a bad bodge but the pads were also modded to fit and did not slide correctly. Makes no sense to risk riding with suspect brakes so I got a used pair from RD Breaker. These were in great condition and I stripped the paint from them and polished them up. Not sure if I will paint them black or leave them as bare alloy.

I removed the carbs and stripped them down and gave them a hot bath in my ultrasonic cleaner, several times till they looked like new. I fitted new float valves and seats, and refitted them on the bike. The fuel lines were looking a bit perished so I replaced them too.




August 2012: Rose tinted glasses failure ?

So in to the garage and out with the spanners and time to get a closer look at things that will need to go on the needs further attention list.

As with most bikes of this vintage the years have left their marks. Luckily for me its 95% all there (missing a belly pan) and in fair condition despite the surface rust and corrosion.

Although the bike has been repainted a while back in the Red Kenny Roberts sytle, the tank has suffered the usual tin worms inside and out. The area under the lower edge has rusted and a hole has been patched. Most tanks of this age will have suffered the same fate, so the option is to source a good used one or try and repair it.

The front exhaust downpipes are pitted badly, years of muck and salt being flung from the front wheel have made them beyond repair. The left hand one has a small hole in it, which blows oil and smoke under the engine and has left a right mess. But the rear sections of both are in great condition, so maybe this bike escaped being slung down the road. The best way forward is to get some other exhausts and cut and re-weld replacement front downpipes. Ideally I’d like some aftermarket expansion pipes but they are expensive new (cira £450) or used (£200) and think I’ll keep it standard until I have it back on the road and see what cash I have left.

You can see from the picture how the frame has suffered too, lots of blotches of rust. I will have to strip everything down and get the frame media blasted, inspected for cracks, zinc primer then powdercoated.

June 2012: The bike I bought to restore

 This is the bike just after I bought it. Sold as a rolling restoration project. Had a years MOT and had been ridden quite often. First things to note were, the belly pan was missing and the fairing was an aftermarket one. Oh and the paint scheme was non-standard “Kenny Roberts” job which I don’t really like anyway. It does not have matching engine and frame numbers, so even if I restored this back to near factory delivered condition it would not be worth as much as a matching numbers bike. But my aim is to rebuild it to a good condition and to ride it as Mr Yamaha intended.

So for the first few months I just intended to ride it and then SORN it and strip it over the Winter months, however the Bike clearly had other plans and started to give me grief when I used it.

It was a pig to start and the right-hand cylinder only fired when it had the mind to do so. Very frustrating and we almost fell out and joined the ranks of the hundreds of failed projects you see listed on ebay every week. When it did run though it pulled strong and showed me that the engine could be worth sorting,  though to be fair the clutch was slipping too, but still allowed me to pop the odd wheelie and put a stupid grin on my face. Funny how riding this bike made me regress to being 20 again and acting like a loon after only one outing.

So into the garage for the first spannering session