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.
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.
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.
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
I’ve started this blog to keep a record of my re-build of a 1983 Yamaha RD350 YPVS LCII and as work progresses then I hope to keep things updated.
So why choose a 350 Yamaha ?
In the UK today there is a big “retro” scence, be it with cars, fashion, music etc. There are quite a few people attempting to re-live some part of their history by restoring something they have fond memories of, such as a Motorcycle. So I’m jumping on the Bandwagon to try and recapture some of my mis-spent youth.
I have been riding Bikes for 30 years now and over this time I have only been without a bike for a few months. Most of the bikes I have owned have been Yamaha’s and the majority have been two-strokes. I owned 2 Yamaha RD 350 YPVS’s and always remember the great times I had on them and the buzz I got from riding a fast (for its day) two-stroke.
This is the first RD350 YPVS LCII that I owned in my early twenties. It had the usual sticker applied to the nose fairing where the previous owner had crashed it. I put the very second hand Allspeed exhausts on it, they made it sound fantastic. This bike used to blow oil out of the power valve covers and would cover my white trainers with two-stroke sludge every ride. I never got the thing to stop leaking despite changing all the power valve seals.
This is the second one I bought, it was an ex-race bike. It was run in the Production Racing Class by a friend. You can see its a bit of a mix of parts and been modded to race. The frame is an LCII, but the forks are “variable damper” from a later model and the tank/side panels were from the full fairing model. The tank was very bashed in as the guy who raced it liked to come off his bikes a lot ! The handlebars were clip-ons and the homemade rearsets (with pilion pegs removed) allowed the bike more ground clearance. Note the screen was missing (smashed) and the indicators were gone too (who indicates on a race track anyway !) The engine had been proddy tuned by Stan Stephens (I think it was anyway, but neither of us can remember) and it went so much quicker than a standard 350. Top speed was about the same as an untuned bike but this one just got there so much quicker.