Alternator belt replacement

GRiSO Capo Posts : 107 Join date : 2018-06-10

My bikes in for its annual service and MOT next week. It's a 2015 with (approx) 12000 miles (20000 km). I don't get in as many miles as I'd like due to work and family commitments, but I do like to make sure that it's serviced annually. The schedule says the alternator belt should be adjusted at 20000 km and replaced at 50000, but I've also read on another thread to change it every 3 -4 years.

So do I work on the basis that it's only done 20000 km and needs adjusting, or do I work on the basis of it's five years old and should be replaced?

Cheers

GRiSO Capo Posts : 10420 Join date : 2013-05-29 Age : 67

Have a look at it. If it looks fine and isn't cracked or loose? Leave it alone.

GRiSO Capo Posts : 107 Join date : 2018-06-10

Cheers Pete - I'd thought of doing that, but wanted reassurance it wasn't a cop-out

Don Abbondio Posts : 162 Join date : 2015-12-19

I am thinking about replacing mine, believe to be orignal from 2011 which now has 46,000 + miles, I gather there are quite a few alter native belts which are pretty much same lenght + or - a little. Is there sufficient adjustment to accomodate these?

thanks

GRiSO Capo Posts : 10420 Join date : 2013-05-29 Age : 67

Yup. Gimme a prod if I forget but I can give you the Gates # if you wish. The factory belts aren't particularly spendy but few shops will have them on the shelf. The Gates option is available pretty much anywhere.

Don Abbondio Posts : 162 Join date : 2015-12-19

OK thanks, I do have some cross references
Gates 4PK738 = 738mm
Gates 4PK740 = 740mm
Cadna 290K4 = 29" whic hI think is 736mm

GRiSO Capo Posts : 1471 Join date : 2015-01-04 Age : 63

Gutsi Bits have 1 in stock at £19.90 + £3.50 postage..... I bought one ages ago and keeping it until the old one starts looking rough.... Main related problem I've already had was one of the plastic cover bolt was completely rusted in and had to be drilled/tapped out after it sheared (even 'special extractors' wouldn't touch it......funny enough (not) had identical problem at same position on guzzi V50 front cover - guess it's where the water spends most time.

Don Abbondio Posts : 162 Join date : 2015-12-19

Cheers, I was thinking about being a cheapskate Smile

I replaced the front cover bolts with stainless - so hopefully will come apart OK.

I haev wondered about the belt as a couple months ago I spent a log of time riding through floodwater about foot, foot and half deep.

Grignapoco Posts : 189 Join date : 2016-09-09

BrianD wrote:: Cheers, I was thinking about being a cheapskate

I replaced the front cover bolts with stainless - so hopefully will come apart OK.

I haev wondered about the belt as a couple months ago I spent a log of time riding through floodwater about foot, foot and half deep.

If not already done it could be beneficial to grease the suspension bearings.

GRiSO Capo Posts : 721 Join date : 2015-01-13 Age : 67

Can someone tell me how much has to be removed to get at the top two bolts and get the cover off? Or the best way to go about this.
Thank you.

John

GRiSO Capo Posts : 10420 Join date : 2013-05-29 Age : 67

I've been a bit busy over the last few days but I'll try and answer this and a few other questions by the weekend if I can.

Nibbio Posts : 519 Join date : 2017-11-09

Here is a post I did earlier 2007 2V/cylinder
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GRiSO Capo Posts : 721 Join date : 2015-01-13 Age : 67

Thanks Roy. Very helpful. That’s swimming in the deep end for me......

Don Abbondio Posts : 162 Join date : 2015-12-19

Fitted new alternator belt yesterday, believe it's original so about 10 years old and 50K plus miles. slight cracking on ribs.

Belt fitted - 4PK730
Original belt length - 740 (outside measurement)

May be useful to someone

Squinternotto Posts : 1 Join date : 2021-03-05

I bought a GRiSO 850 2007 with approx. 30,000 km. Suddenly my battery was empty. Cause: Alternator belt was completely gone. I only found some tiny pieces when replacing it. So it was obviously that the old timing belt was the original one. Not only km's count also the age of the belt is a reason to replace the belt.

GRiSO Capo Posts : 1449 Join date : 2016-01-25 Age : 69

Just replacing my alternator belt this afternoon.
There is corrosion and semi-seizure on: one screw holding the ecu, some screws holding the outer cover, the breather stand-off boss, the alternator lock screw and the adjuster screw.
I have removed both exhaust down pipes and both 'wings'. Doesn't make it 'easy' - but it is letting me get all of these screws out with the minimum of collateral damage.

Any metallurgists out there? If i use coppaslip on stainless bolts in aluminium will that lead to more or less electrochemical corrosion?

Montanarolo Posts : 10 Join date : 2014-12-03

Has anyone checked their alternator bearings when changing the belt? My G11 is coming up to 40K and I have this strange noise from the front of the bike. Sounds like dry bearing noise. I have removed the cover and checked the belt - looks like new- but have not removed it yet, so have not spun the alternator to check for any roughness
Cheers

Nibbio Posts : 713 Join date : 2021-07-30 Age : 60

Dave R wrote:: My bikes in for its annual service and MOT next week. It's a 2015 with (approx) 12000 miles (20000 km). I don't get in as many miles as I'd like due to work and family commitments, but I do like to make sure that it's serviced annually. The schedule says the alternator belt should be adjusted at 20000 km and replaced at 50000, but I've also read on another thread to change it every 3 -4 years.

So do I work on the basis that it's only done 20000 km and needs adjusting, or do I work on the basis of it's five years old and should be replaced?

Cheers

If it aint broke dont fix it. Cost a pretty penny for removal and replacement from a shop.
Total ballache for the home mechanic
Have never seen mine, bike has 15k and is 12 years old.
You'll know if it snaps the battery will stop charging.

GRiSO Capo Posts : 10420 Join date : 2013-05-29 Age : 67

4PK-730, 735 or 740 will do a 725 is just a smidge too short.

Changing the belt is hardly a difficult job. Yes you need to drop the ECU off, (On a GRiSO.) to get to the top bolts on the belt cover but that and the left 'Wing' are about it. There is a special tool for setting the belt tension but it's completely unnecessary as long as you have some grasp of how to set a belt.

Thing with belts is that they will either tend to fail early, (Due to being too tight or too loose, usually the latter.) or last a very long time. We've had 150,000 km bikes in that have never had the belt changed. I changed mine recently on the yellow bike at about 80,000km and it basically looked brand new. No cracking or discernible wear. I thought it was time though.

Biondino Posts : 287 Join date : 2021-08-19

Pete Roper wrote:: Have a look at it. If it looks fine and isn't cracked or loose? Leave it alone.

Hi Pete,

To do a visual check on the belt it is really necessary to take all the steps on the manual (remove the control unit, exhaust headers,....)? Just checking ir there would be a short cut

....

Thanks....

GRiSO Capo Posts : 10420 Join date : 2013-05-29 Age : 67

That's about it. You need to get to the bolts to get the belt cover off. Those bits are in the way. No need to disconnect the ECU from memory, just hang it away to the side a bit.

Biondino Posts : 287 Join date : 2021-08-19

Tanabuso Posts : 68 Join date : 2020-06-13

I have changed the alternator belt this year.

Here are some fotos from the original Guzzi and the Dayco 4PK 730.

The Dayco belt fits nicely.

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Biondino Posts : 287 Join date : 2021-08-19

Hi
Did you use the special tool to measure the belt tension, or did you tensioned it by feeling?.....

Tanabuso Posts : 68 Join date : 2020-06-13

Hi,

in fact i used the tool 020677Y (50 Nm) - bought it from Stein Dinse years ago.

I have done the job alone by myself and it worked fine for me.

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