LCGB Forums

Just put a new Iwis chain in and replaced the original tensioner too as recommended in stickys book.
I went for the MB one. This is set up at the lowest position it can go yet the new chain was just under the 6mm play suggested.

My question is, when I throttle up I am getting a whining noise. Is this normal with a new chain until it stretches a little or should I be thinking of taking it apart again. I'm really reluctant to take it all apart just yet as it's taken me a while to get the time to do this and the exhaust is a frigging nightmare to install
I was going to give it a little scoot around the block to see if it settles down but thought I'd check with you guys first incase something is ready to go bang.

TIA

I’m unsure as to what your noise is ? But what i do know is most chains stretch within 100m. I’m guessing your mb tensioner is a push up type ?
Obviously if there’s a noise there that Isn’t normal then you need to look into it.
Sorry for not been much help.

Yes the tensioner is a push up one.
The chain was tight before the tensioner was installed. At the moment the tensioner is set as low as it will go (although still in contact with the chain it's not pushing up or adding pressure to the chain) the chain is under it's own tension between the sprocket with minimal slack.
I just wondered if this was normal and would bed in after a few miles?

What chain and sprocket combination is it?

Danbretta wrote:The chain was tight before the tensioner was installed.

Too tight a chain will add loading to the bearings, sprockets, cause premature wear of them & the chain itself.

Tensioning further will make matters worse.

In certain scenarios where the ideal slack is "just enough" the tensioner can be omitted.

You would have been better to have obtained a chain a "half link" longer or obtained a "pre stretched" chain (as opposed to an old, worn one) but a "Lambretta Dealer" would be unlikely to hold stock without an even greater premium on the cost of what is just an industrial power transmission component.

For decades, I have assembled any new chains from bulk packs (five metres normally) such as genuine Renold, TD Cross & Morse etc. On one occasion I leant one of my chains to a very well respected tuner @ a race meeting, only to be given a Rolon chain back as the return @ the next meeting! Never trust a Harboro' Bed Wetter!

Are you sure it’s not from elsewhere? Gearbox ? Kickstart rubbing the clutch or 1st gear? Does the noise change clutch in , in gear etc.

dickie wrote:What chain and sprocket combination is it?

15/46 socket set up (standard 150LiS) Chain is 80 link.
The chain looks genuine IWIS it has the logo stamped on each link although the box didnt have the holographic stickers on the ends, just plain silver.

Warkton Tornado No.1 wrote:

Danbretta wrote:The chain was tight before the tensioner was installed.

Too tight a chain will add loading to the bearings, sprockets, cause premature wear of them & the chain itself.

Tensioning further will make matters worse.

I dont think the tensioner/guide is pushing up on the chain, it's on its lowest setting and just touching the chain, I think I might have to bite the bullet and strip the chaincase off again and see if something wasnt put back right or rubbing. I have a feeling it could be the chain too tight though.

Thanks for everyone's help, I'll try and upload a video if I can pick the sound up.

I remember that my chain in my 175 was pretty tight with the same combination. I think the chain is Iwis, but may be DID.

Have a look http://www.ilambretta.co.uk/forum/viewtopic.php?f=7&t=10472&start=60

dickie wrote:I remember that my chain in my 175 was pretty tight with the same combination. I think the chain is Iwis, but may be DID.

Have a look http://www.ilambretta.co.uk/forum/viewtopic.php?f=7&t=10472&start=60

I see what you mean, similar to mine. Did it make a whining noise or did you have any issues with it?

Just popped out to the shed to film the noise if it's of any interest. It's a bit dark but its the sound I want to try and pick up.

https://youtu.be/XIjiGUbmkNU

Anything sound familiar to anyone?

MK Monty wrote:Are you sure it’s not from elsewhere? Gearbox ? Kickstart rubbing the clutch or 1st gear? Does the noise change clutch in , in gear etc.

Noise still stays with clutch in, it's more evident when revving, not really noticable when ticking over.

I have uploaded a video.

Very hard too distinguish on the noise

Danbretta wrote:I see what you mean, similar to mine. Did it make a whining noise or did you have any issues with it?

No, no funny noises. Still going fine now.

Danbretta wrote:Just popped out to the shed to film the noise if it's of any interest. It's a bit dark but its the sound I want to try and pick up.

https://youtu.be/XIjiGUbmkNU

Anything sound familiar to anyone?

I can't hear anything that I'd be too concerned about. I've used idler tensioners in the past that sounded even whinier because of their rotation.

I'm sure that your own diagnosis is correct.......very vespa-ish

ULC Soulagent wrote:Very hard too distinguish on the noise

Yes it's not obvious, I didnt notice the noise with my old chain but then that was stretched to its limit. I have only had this scooter on the road a year so I'm still learning.

This video popped up on my youtube suggestions this morning. The whining/whirring noise is a bit more obvious on this guys scooter but I haven't a clue what he's talking about. Hopefully he's saying hes installed a new chain and all is perfect

https://youtu.be/i6jkecKQlls

[/quote]

I can't hear anything that I'd be too concerned about. I've used idler tensioners in the past that sounded even whinier because of their rotation.

I'm sure that your own diagnosis is correct.......very vespa-ish [/quote]

Probably me being over cautious and doubting my own mechanics. I'm still learning and relatively new to the pleasure of lambretta ownership.

I'll take it for a local spin and see if how it goes.

Problem is, going for a spin isn’t really going to tell you anything. Effects of a slightly tight chain as has been mentioned are longer term. Even if it is a bit tight its not going to go bang. Knowing that the tensioner isnt acting now why not remove the doubt that will be nagging you and either remove the tensioner altogether or add a link to the chain and tension it? Yes it’s a ballache to strip down again but at the same time you can check for anything rubbing

Hat wrote:Problem is, going for a spin isn’t really going to tell you anything. Effects of a slightly tight chain as has been mentioned are longer term. Even if it is a bit tight its not going to go bang. Knowing that the tensioner isnt acting now why not remove the doubt that will be nagging you and either remove the tensioner altogether or add a link to the chain and tension it? Yes it’s a ballache to strip down again but at the same time you can check for anything rubbing

Fair comment I think I'll have to psych myself up to strip it all apart again and double check everything.
I did find a pic on my phone I forgot I took when I was deciding what bottom guide to install. I might do as was suggested earlier and remove it altogether and check back in on it after a bit of use.

It can be seen from the tensioner that it is lifting the chain even before being fastened in place. Factor in the inside corner radii of the tensioner & it will lift further creating more pressure on the chain. That's not to say it is a "schoolboy error" but something that usually requires fettling. Welcome to the World of Lambretta.....

You don't have to, but for the reasons above on their own, I would temporarily remove the tensioner & run the engine again. Listen closely & report back. If you still think that chain needs a half link, then I'll modify yours FOC if you stand P&P.

Once the tensioner is out (I'd remove the bottom one in any case) you can elongate the slots in any case, fettle the cast corners (a lot!) so that a substantial, thick packer can be fitted beneath the wo M6 securing nuts & retaining washer plate. You might need longer, rolled thread, M6 studs. Whilst doing that, I usually remove the nylon slipper, countersink for M6 socket countersink screws & tap the alloy out to M6, although I have Helicoiling kit if the hole results in a baggy thread. It's just neater & a better way of sinking the screw heads IMO than sharp cornered, shallow counterbores.

Please let us know how it goes, whatever you decide

(Don't forget that now is the time to write to Santa because a 1/4" hex drive impact driver with additional deep sockets is a must. I used to think that impact drivers were only for loosening, but with the Milwaukee I have, it is so controllable, I use it for loosening & tightening with final torquing via a torque wrench)