BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

Hello Friends, looking for some thoughts. After I crack up my bike, then ride for a few minutes and the engine warms up, you hear a steady whining noise comeing from the front of the engine. I think it may be the poly v belt since the bike has 38K miles on it, and I don't think the previous owner ever changed it. any thoughts?

Change the belt. They are cheap and I've been through three in 90,000 kms (on my fourth). Look closely at the housing and you will see some open vented areas along the sides of the plastic belt cover (for cooling and water drainage). These allow small stones and dust to enter the belt area. The front wheel flicks up 'stuff' which bounces off the engine case and into the little vent holes. The belt gets chewed up, chipped and nicked, then makes noises. At 38,000 miles, yours may just be worn out. It is unlikely to be a bearing as these seem to be very long-lasting.

thanks

PM sent in response to your Q - I have copied it here is at may be helpful to others. I now carry a spare belt on my trips - It's one of the few things that might fail and is repairable on the road.

COPIED TEXT
The belt tends to make a 'squeaking' or 'chirping' noise rather than a 'squeal' like a car fan belt makes when it slips. Mine was loud enough to be heard with helmet on and foam ear plugs in, so I guess you would say it was noisy.

It's an easy check. The cover is held on with a few bolts, so have a look. It may still look ok, but if it has nicks and cracks (the usual damage), then it will have a squeak that MAY go away when it warms up and the rubber gets some flexibility. If you have a 'roar' or 'rumble' type sound, it may be a bearing (but very unusual).

Have a listen with the cover off. Don't idle too long. Also feel along the inside of the belt (motor NOT running) for rough nicks and cuts, remembering that the belt is the lightly toothed type. A new belt will be about US$14 as they are about AUD$18 here. I use a Bosch replacement as they seem to be better quality than the BMW ones (and cheaper). Don't recall the part number off-hand.

Hi Mick. Would be of help if you can find the P/number of that belt.
As said, easier to carry a spare, than to be caught out with a flat battery.

Done - It's a Bosch 4PK 605 Multi-Ribbed Super Belt. 40,000 kms or 24 months warranty - But I don't think that covers little rock damage. If you have never taken the front cover off and have done some miles on a dirt road or even a road with blown sand and dirt on it, you may be surprised at how much crap actually gets in there.

My first belt was just 'squeaking'. It was the original BMW one that was starting to crack. Lots of kilometres on it. It was changed by my Service guys for a Bosch belt. I put on a new one (number three) for my Round Aus ride. The one that came off was in pretty rough condition but I had been on a lot of dirt roads and rough tarmac. It lasted 16,000 kms and was found to be full of nicks and chips on the return service. The fourth one went on a while ago, and seems to be holding up well.

They can also chirp if loose (mine was 'chirping' this morning), but with 38k miles, REPLACE IT! (I saw that you ordered one).

Easy replacement and from what I remember, you don't have to remove the tank.

Thanks for that Mick.
Do you loosen the alternator to put it on, or just wind it on?

johno wrote:Thanks for that Mick.
Do you loosen the alternator to put it on, or just wind it on?

Oh nooooo!!!!!! Loosen the alternator to put it on, you may damage the new belt by trying to stretch it over the pullies.

Actually, a new belt has a surprising amount of flex and can just be wound on after the old one is cut off. The pulley 'V' is fairly shallow, so it's no big deal. I can't even recall looking for an adjustment on the alternator to loosen the belt. Don't even know if there is one. The Bosch is slightly tighter than the BMW one, and that seems to reduce the slipping squeal that you sometimes get with an old stretched belt.

Anyone actually found an adjuster for the alternator belt?

Anyone actually found an adjuster for the alternator belt?

Yes. It's a bolt on the inside behind the belt housing, right beside the alternator on the left side. You put a torque wrench on it and torque to the specified torque and hold while you tighten the locknuts on the front. I have the directions somewhere here. ...Looking......will edit this post as soon as I locate them.

Okay here we go. In the diagram they show the torque wrench up on top, but you can't get at it this way. Take off the left oil cooler to access it from the side.

Thanks Phil - That's probably why not too many people 'adjust' the belt. It's easier and quicker to just slip on a new one.

I don't think 'stretching' is as much of a problem as it is on a car. Most of my worn-out belts have been related to old age (the first one), and then stone damage (the next two). None actually broke out on the road. They were always picked up during the 10,000 service intervals, programmed to coincide with the start or end of big trips.

Maybe there are issues with slipping belts, but I would suspect that a belt that's been on a while should be replaced anyway, rather than re-tensioned. It's a cheap part and easy fix. Funny how you never notice some things (like the adjustment).

My supplier doesnt list a 4PK605, only a 4PK600.
I am sure 5mm aint going to make a lot of difference.
I have "wound" on more belts than I care to remember, so it is not a big issue.
Try fitting belts onto a truck engine on a wet, cold night without the correct tools, and you soon learn the tricks.

Gidday Guys
Can anyone tell me if the 4PK605 or 4PK600 V-poly belt will fit an R1100R
or is it just for the 1150 engine

cheers
Arbee

I had a whining noise too....
the Fuel Pump decided it had had enough after i had ridden it 5 yards
after buying the bike.

"such is life" Ned Kelly

Thanks to all for all the great feedback.

After pulling off the belt cover, the belt is actually a 4PK 611.