Beavers Yamaha RD50

[Beaver]

Those who know me, know I've got the worlds most capable adventure bike; the mighty Yamaha V50 repowered (over powered even?) with the finest quality Lifan 125. To allow me to enjoy rides with other people where I'm not having to wait for them all the time, I've been looking for something a bit different*.

* - what I actually mean is I've been looking for something a little bit more motorbike and a little less scooter. I was originally looking for something 100-150cc, but alas, here we are.

A bunch of my fellow small bike enthusiasts have been dabbling in modern technology, and getting about on the likes of new CT125's, monkeys, and groms. After relentless abuse and peer pressure, I almost caved into following suit. But on a rainy morning, lazing on the couch perusing the latest trademe listings - hello, whats this. Jump in the ute and off to Morrinsville (which actually turned out to be Te Aroha). I must have go the timing just right as by the time I got there, he already had 2 others waiting to come view. After some tyre kicking, stories of benchtop rebuilds and back country hoons, a firm handshake was had and it was a done deal.

[Beaver]

Yamaha RD50, not sure which year as no rego details. Late 70s/early 80s anyway. So the story goes the guy I got it off received it as a trade for some machining work. It wouldn't run, but after replacing the crank seals it popped into life. He then proceeded to make all the other bits work. Its had rebuild front shocks and front brake replaced with something off a bigger bike (pulls up a dream). Reckons hes done 1200km in the last 3-4 months since getting it going just fanging about the back roads. The electronics all work but someones definitely used too much electrical tape. Other than a miss matched side cover, its all there and and all works. 

So far I've given it a polish and tighten up some bolts. Been on a couple of rides around town and its great. Doesn't really like hills but hey, that's all part of the fun. Short term will just continue to ride it and sort out any little niggles. Longer term I'd like to do a slightly stripped down/clean cafe racer type "build". 

 

[GregT]

Don't cafe it please. They're sufficiently rare and collectible to make it worth doing the final bits of sorting. Find something less collectible to modify.

I had a mint one through the workshop some years back. It had come with a big bore kit fitted and the jetting needed sorting. went well and still had the OE barrel with it. Owner brings it out for the big local runs.

[Mop Head]

I have ridden one of these a fair bit. Don't be scared of changing gears 82 times per kilometre. Especially into/out of corners and up hills. When I was at the bike shop we had a guy bring back the big brother (RZ50) after owning it a day because it 'wouldn't accelerate properly'. Turns out he would slow for roundabouts or corners and leave in 4th or 5th then wonder why it wouldn't accelerate out of them.

+1 on the tidying it up as is - Cafe racers are just discomfort disguised as 'cool factor'. But it's your bike at the end of the day. 

[Snoozin]

Always had a small pine for these, what a neat machine man! Enjoy the wee ring-dings!

[Beaver]

Quick today up jobs using a red that resembles the factory colour (pretty happy with it considering I just picked the closest one from the 5 reds at supercheap). One of the side covers was brown, and the seat tail had faded a lot (both plastic). Low effort but max reward.

It's got a strangle small wobble (up and down) at speed which is slightly disconcerting. So will pull the wheels off and check the bearings and axles etc.

In the mean time just keep on nanging.

[Beaver]

Tidy up complete

 

[Beaver]

Seat needs attention as the foam is chooched. And lack of centre stand is really annoying. Side stand put bike in gangster lean and needs solid ground/concrete.

[Goat]

https://page.auctions.yahoo.co.jp/jp/auction/p1070656976

[Beaver]

Was having intermittent headlight issues and the oil warning light would come on and off at the same time. Which was odd not only due to the timing but the fact I couldn't find any trace of an oil level sensor.... so I exposed a lot of the wiring and found a few gremlins (loose connections, bad crimps, suspect earth) so sorted all that out. In the process I confirmed that there isn't an oil warning system at all (must be a clock of a different bike) and that it's the high/low beam indicator light feeding that spot. Regardless, it all works as it should now.

Have also ordered some new tyres as the date stamps indicated 1980 and 2004.....so needed doing anyway, but I'm also chasing a shudder/wobble/chatter from what feels like the front end. I drains the forks and found not enough oil, so refilled those to spec as well - perhaps that may help also.

Ring ding ding 

[GregT]

When the new tyres go on the wheels will be balanced. this should show up any out of round or noisy wheel bearings.

[Beaver]

31 minutes ago, GregT said:

When the new tyres go on the wheels will be balanced. this should show up any out of round or noisy wheel bearings.

Do you mean that as in the tyre shop will balance them, or because the tyres are new they will be round? I'll be fitting them myself. Will be checking the bearings when the wheels are off as well 

[GregT]

A shop would automatically balance them. Do you have a wheel stand and the experience to balance your own ?

Possibility the front rim is out of round from your description.

[tortron]

Turn bike upside down (or hang it from the rafters) 

Put zip ties on the forks and cut to length to mark the edge of the rim

 

Spin it and see how much difference in hop and wiggle there is

[Willdat?]

1 hour ago, Beaver said:

Do you mean that as in the tyre shop will balance them, or because the tyres are new they will be round? I'll be fitting them myself. Will be checking the bearings when the wheels are off as well 

My SR741s had an impressive wobble from new, didn't balance them. Would probably be less tiring if I had...

[Beaver]

2 hours ago, tortron said:

Turn bike upside down (or hang it from the rafters) 

Put zip ties on the forks and cut to length to mark the edge of the rim

 

Spin it and see how much difference in hop and wiggle there is

Lol fuck that ain't happening. Sounds like it's worth getting them fitted at a shop. 

[tortron]

It's quick and easy to gauge if a rim is eggshaped

Like this but a bigger ziptie

 

[Beaver]

Oh I get the science, just not sure how I'm meant to flip a motorbike over and hang it from the rafters....

[tortron]

Or hang it from the rafters, not both

Just whatever to get the wheel off the ground and free spinning

 

[Beaver]

Reading your posts sober made much more sense haha. Front has a very minor flat spot. Took for a ride and it's much nicer after doing the front fork oil.