What would you do?

ChasF

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We're just back from a 1600 mile tour around Spain on our 1989 R100GS which is just coming up to 50k miles on the clock. The bike ran really well but there are some things that need attending to. The main issue although not causing much of a problem at the moment are the cylinder stud threads. I've repaired two (one on each side) using helicoils but there is at least one that now requires attention and this time I plan to use big sert inserts and may even replace the helicoils with these as well. I'm also going to fit new valves as apparently the OE valves are suspect after about 40k miles but I need advice on how far I should go here as I'm looking for some more power. I plan to fit Moorespeed high comp pistons so I'm wondering if the heads would benefit from the full Moorespeed treatment?

Other engine work is mostly related to oil tightness. I plan to fit new pushrod tubes and seals and possibly a deep sump of some sort but again whilst I've got everything in pieces what should I change as a metter of course - timing chain, crank seals, main bearings, big ends etc.?

The other areas which I'll be attending to are the brakes, I plan to give a twin disc conversion a go which may well include a front wheel rebuild with stainless spokes. The geabox seems fine at the moment but I think it should be looked at given the mileage. I'm hoping to end up with a bike that I can use for similar trips to our Spanish jaunt but without the anxiety that comes from reading too many horror stories on forums.

One last issue is, I think, a whine from the final drive. I refitted the screen about 2500 miles ago and now hear a lot more of what's going on. I can hear a constnt whine when riding at between 45 and 60 mph when the wind noise takes over. The whine is consistent doesn't matter if I'm in 4th or 5th gear so I'm guessing it has to be the bevel box - is this anything to worry about or do they all do it?

Any advice much appreciated.
 
Well, speaking from experience, I can certainly save you a lot of hassle in one area - dont bother twin discing the front brakes, unless you want to carry a few extra kilos of unsprung weight around, that is. More complexity and weight for very very little benefit, poor return IMHO. Better to upgrade the rotor to a larger 320 mm one - kits are available. And no need for stainless hoses either - about the same power, much more wooden feel.

The whine could still be a gearbox noise, or a final drive noise, or maybe the alternator, maybe timing chain, tyres perhaps.....etc etc......but to a large degree all airheads make their internals well known to the rider. Its charactor, revel in it :-)

Personally I would do the head studs as that is clearly a known issue, and potentially a failure point, and while you in there refresh the heads/tubes and bearings etc. The rest I would do when it needs doing.
 
Thanks for that. Has anyone put any miles on a bike fitted with the HE disc before it warped?
 
i had an HE disc on my PD which was ridden hard two up, sometimes in the mountains and it never warped. i've had one on my G/S for 7K which has also seen some fairly robust mountain use and that is fine too.

both bikes had the standard caliper fitted and both had greatly increased, though still not great (ie. modern) braking power.
 
So how much do you think is due to using the standard caliper. There are some theories that the slightly narrower pads used by the 4 pot caliper contributes to the warping problem. I'm just rebuilding the original caliper and will give it a try with the standard diameter disc. I think that when I fitted the four pot the original as virtually seized up so the four pot showed a marked improvement but it's still hard work stopping the thing on steep mountain descents when 2 up with luggage
 
Wurth timeserts are good for repairing cylinder stud threads in the engine case. Don't forget to drill the oil feed in the top studs.

80/100 valves are usually good for 80k miles. The smaller 650 models are 50k miles.
 
Just my 2p, the 4 pot k series caliper ate brake pads at an alarming rate and was no better than the cast iron PFM disk and standard caliper on my friends bike. You can guess what I'm using now.
 
You mention replacing valves with non OE, just watched this don't know if it has any relevance. i'm a novice, so just ignore me if i'm off the mark :-)

https://www.youtube.com/watch?v=R1rI3pog1DU

Thats an interesting video, I hear on here from time to time about supposedly reputable firms screwing up engines or gearboxes with inferior bearings etc. I think if I was having work done I'd be guided by some of the gurus on here. For example I'd have presumed stainless valve to be a superior item, obviously from this video I'd be wrong and Ted explains why too which is good as I accumulate another little bit of knowledge and potentially avoid an expensive mistake in futuire.
 
Thats an interesting video, I hear on here from time to time about supposedly reputable firms screwing up engines or gearboxes with inferior bearings etc. I think if I was having work done I'd be guided by some of the gurus on here. For example I'd have presumed stainless valve to be a superior item, obviously from this video I'd be wrong and Ted explains why too which is good as I accumulate another little bit of knowledge and potentially avoid an expensive mistake in futuire.

The problem is that every expert has his own opinion that usually relates to the kit he's selling. I have moorespeed stainless valves in two of my engines but they are fitted in conjunction with colisbro valve guides. No issues with them at all after thousands of miles of riding.

MooreSpeedValves.jpg
 
Good, thanks to Steptoe for clarifying the valve situation. I'll just clean them up again and grind them in. I think I'll give an HE disc a go it's only 263 euros from Boxer Supplies! although I think 2 discs is still a better prospect. I'm going to fit a new set of stainlees downpipes and y piece from boxer supplies as well. Is there an OE silencer available in stainless steel? Air filters: do paper filters clog eventually. Apart from the extra induction noise would a foam filter offer some improvement?
 
I think the consensus is that the stock air filter is the way to go. Blow them out every service and replace when necessary, they're not expensive. We have the odd bit dust in Oz and the stock filter does the job. In extreme conditions on an extended ride carry a spare.
 
When I was riding my pd every day I had a problem with pattern air filters swelling in the winter with the damp air strangling performance. Standard filters sorted this out and were actually cheaper from bmw than the patterns. Probably not such an issue in Feance though.
 
So the foam filters available are more show than go then - I ask because I've fitted a foam filter to replace the paper one on my 690 and it certainly sounds like it's more powerful.
 
Good, thanks to Steptoe for clarifying the valve situation. I'll just clean them up again and grind them in. I think I'll give an HE disc a go it's only 263 euros from Boxer Supplies! although I think 2 discs is still a better prospect. I'm going to fit a new set of stainlees downpipes and y piece from boxer supplies as well. Is there an OE silencer available in stainless steel? Air filters: do paper filters clog eventually. Apart from the extra induction noise would a foam filter offer some improvement?

Again, from direct experience - dont bother with the foam filter - noisy noisy noisy. Messy to service as well - and it will need doing more frequently. No gain in power, if fact unless you dyno the bike it makes it worse, despite what the manufacturer will have you believe. Also, be wary about y pieces (plenty of info on here about this issue) - again if you ditch the standard collector you are likely to make things worse (goodbye mid-range). Lots of peeps on here have done this and reported negativly, and a fair few have now re-fitted the OEM collector box which has just become availiable again

Consenus seem to be "keep it OEM"
 
Rather than mixing and matching parts. If you look on the moorespeed website he offers power kits that deliver percentage increases in power, these have all been tested and proven. If it was me I'd go down this route.

I've recently taken a full on moorespeed engine out of my pd and refitted a standard engine. The standard engine suits the bike so much better.

ive also ditched a kehin silencer and refitted s standard stainless one - this on its own is a major improvement.
 
With head work you should replace everything at the same time, and the technician will fit compatible valves, guides and seats, alleged problems usually are the result of mismatched components.
Richie Moore's race motors seem to hold up OK and make good power -------------.
Remember that Ted Porter, the guy in that link, fitted and sold these tapered bronze bushes to replace the stock needles on the rear paralever joint.
The design was just wrong and there was no way they could work. Full stop.
But this guy couldn't see the obvious, claimed to have fitted them successfully, kept on selling them after he knew they were junk and although they were dangerous never issued a warning or recall, or issued a refund to those that bought them.
So to see him bagging other folks work is pretty much a sick joke.

And he doesn't do much himself, most all is farmed out to whoever is available and cheap enough on the day, he just drums up the work by bad mouthing others.
Darling of the ADV crowd of course!

Best bang for the buck with brakes is a decent lever/ master cylinder and proper HH pads.

Check for play at the rim on the rear wheel, the bearings in your hub should be preloaded so there shouldnt be much, and also check the temp after a run, the final drive should be slightly warm but any heat is a sign of problems.
Nothing a sensible person can do to it themselves, probably best to look for a good second hand one , and perhaps consider your choice of lubricant if you find one.
 


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