Expensive work needed!

[Nickster78]

My bike passed its MOT with flying colours on Saturday but the mechanic told me that the noise I had noticed shouldn't be there and that he thought it was the scissor gears???? (don't ask me!) and that to fix it he would need the bike for 2 days and because the whole engine needs to be lifted out that it will costs about £300. (not chuffed)

Has anyone had this problem or does anyone know anything about this?

(Apparantley it only happens on the older sv's as newer components have been updated.)

[BURNER]

How many miles has your bike done?

[Nickster78]

Bikes done 20,000, however it had a reconditoned engine put in it just before I bought it as the last owner had run it dry of oil and that has now still only done 5,000!

[northwind]

You want to get a professional second opinion... What sort of noise is it?

Also, it could be I'm just dense, but WTF is a scissor gear?

[embee]

Also, it could be I'm just dense, but WTF is a scissor gear?

....it fits between the thrimble washer and the waffle sprocket


(no, I've no idea either! :? )

[Sid Squid]

I don't think there are any of the type gears sometimes referred to as "scissor gears" on an SV.

[Nickster78]

Apparently the scissor gears are on the camshafts.

[Sid Squid]

Is this a 650 or a 1000?

If it is, as I think it is, a 650 there aren't any of the quietening 'scissor gears' on the cams, they're only fitted to the 1000s.

Far more likely is that the camchain tensioners are a little sticky, to make them work again usually doesn't require their replacement, in fact it usually doesn't even require their removal, just the cap removed and the plunger reset.

Please check this very carefully before going any further.

Of course if you do have a 1000, it is a possibility, however the problem was mostly confined to the early TLs, I've not heard of a problem with the SV1000 cam sprockets as they are of a quite different design.

[weegaz22]

well thats a new one to me :roll: scissor gears? :roll:

[weegaz22]

Is this a 650 or a 1000?

If it is, as I think it is, a 650 there aren't any of the quietening 'scissor gears' on the cams, they're only fitted to the 1000s.

Far more likely is that the camchain tensioners are a little sticky, to make them work again usually doesn't require their replacement, in fact it usually doesn't even require their removal, just the cap removed and the plunger reset.

Please check this very carefully before going any further.

Of course if you do have a 1000, it is a possibility, however the problem was mostly confined to the early TLs, I've not heard of a problem with the SV1000 cam sprockets as they are of a quite different design.

sounds like a older 650 to me sid as he said

Apparantley it only happens on the older sv's as newer components have been updated.)




in which case id agree with sid and say its the tensioners

[Nickster78]

I do indeed have a 650, I don't really know enough about all this to question their judgement though will as you advise look into it a bit further before I go ahead and pay them!

[weegaz22]

i take it that you are hearing a ticking noise at around 4-5000 rpm ? if so then its the tensioners, a pretty common sv problem

[Sid Squid]

Straight cut gears give no side loading but can be noisy, to reduce this often they are a split gear with the two parts offset by a tooth or two, and spring loaded, usually the offset part is much slimmer, it takes no load, it just reduces lash and therefore noise.

These are sometimes referred to as "Scissor Gears",

[Nickster78]

I have the ticking noise which I have been told previously is the tensioners and can actually be ignored and I now also have this other noise (deeper and I wouldn't describe as a tick) which the enginner seemed to think was the scissor gears!

[weegaz22]

Straight cut gears give no side loading but can be noisy, to reduce this often they are a split gear with the two parts offset by a tooth or two, and spring loaded, usually the offset part is much slimmer, it takes no load, it just reduces lash and therefore noise.

These are sometimes referred to as "Scissor Gears",

you mean a slash cut gear like in a gearbox? didnt the 1000 engine run on a cam chain?

[weegaz22]

I have the ticking noise which I have been told previously is the tensioners and can actually be ignored and I now also have this other noise (deeper and I wouldn't describe as a tick) which the enginner seemed to think was the scissor gears!

is it happening underload? or just in neutral? is it a knocking sound? what rpm does it do it at? does it do it warm and cold?

you ever had your valve clearnces set?

does your oil look like there is bronzy metal fillings in it?

[Mike1234]

Definitely take it to another dealer for a second opinion. Why not try JHS Racing in Bristol?

For 300 quid you can get another engine!

[Nickster78]

I am going to take it to Cheltenham for a second opinion, hopefully at the weekend. (took it to gloucester for the MOT).

Mechanic told me that if the springs go the could do further damage to the engine and possible could cause the bike to seize so has advised me not to take it too far, is this the case then?

High cost due apparently to the number of labour hours required considering lifting out engine etc.

Does it under load and when warm, not sure about in neutral can't say I have noticed it, however that doesn't mean its not there!

Can't say I have ever had my valve clearances set either sorry.

Very new to all this only had the bike 12 months (first bike).

[Captain Nemo]

Nickster,

sorry that this isnt to do with you problem , but i just have to say this.

your georgeous !!!!

there said i now :oops:

[Carsick]

Nickster,

sorry that this isnt to do with you problem , but i just have to say this.

your georgeous !!!!

there said i now :oops:
Cold shower for the aquanaut, methinks.

[Iansv]

I completely 2nd that... Just didn't wanna be first to say it...

hope the problem gets fixed

[Sid Squid]

Straight cut gears give no side loading but can be noisy, to reduce this often they are a split gear with the two parts offset by a tooth or two, and spring loaded, usually the offset part is much slimmer, it takes no load, it just reduces lash and therefore noise.

These are sometimes referred to as "Scissor Gears",

you mean a slash cut gear like in a gearbox? didnt the 1000 engine run on a cam chain?

Gearbox pinions are always straight cut*, for they are moved from side to side to engage the different gears, helical gears, ("slash cut" as you say), would give an unacceptable side thrust making gear engagement under load difficult if not impossible, and certainly there would be an enormous load on the selector forks in the unlikely event it could be made work anyway.
The 1000 motor has a camchain that runs to a central idler and then the two camshafts are gear driven from there, in this assembly are the gears referred to as "scissor gears", noise reduction is the intended aim
Presumably the whole idea is to reduce head width as there are no large chain gears on the cams.
Helical gears load up a portion of their thrust on their side faces and hold tight, reducing gear chatter and noise, however in a cam drive mechanism the slight misalignment this would give would make accurate timing difficult, thus the desire to use straight gears, sometimes with the addition of the mechanism in question.


*Constant mesh 'boxes on bikes that is, synchro 'boxes, like those in most road cars have helical gears.

[Nickster78]

Thanks guys!

[sexysi]

Nickster,

sorry that this isnt to do with you problem , but i just have to say this.

your georgeous !!!!

there said i now :oops:
So are you captnnnn
sexysi

[Captain Nemo]

So are you captnnnn
sexysi

hello sailor !!!! :wink:

[northwind]

Mechanic told me that if the springs go the could do further damage to the engine and possible could cause the bike to seize so has advised me not to take it too far, is this the case then?



Well, that by itself's true, but has anyone ever heard of valve springs going on a stock SV engine?

I accuse your mechanic of taking the ****, frankly... See if you can get a written report of what's "wrong", I reckon he'll be cagey to put it in writing...

[Carsick]

I accuse your mechanic of taking the p*ss, frankly...
Hadn't we established that when Sid said that the 650 doesn't even have what he claims is wrong?

That's not to say something isn't wrong, but this mechanic has probably decided what he's going to claim the job is.

[Viney]

Pesonaly i think the mechanic is getting a bit muddled with the Scissor sisters. Maybe he was listening to them when MOT'ing your bike.

Dont worry about it, mines running on 37000 miles and its fine. Im sure though we could all come down and have a look for you as a damsel in distress!

[northwind]

I accuse your mechanic of taking the p*ss, frankly...
Hadn't we established that when Sid said that the 650 doesn't even have what he claims is wrong?

No, we'd established that he was talking crap, but there's a difference between talking crap and taking the **** :)

[Nickster78]

Thanks for all your thoughts, I will now have to wait until I can get a second opinion on the apparent noise and until then am not parting with any cash, however convincing he may seem! (and however annoying it may be that I am not currently taking the bike out until I know what is wrong with it)