Engine mount cones

[coaster]

I'm in the process of re-fitting my Avanti engine which now has an Atomic Ultimate reed valve. Unfortunately the manifold fouls on the frame and after 'relieving' the top of the manifold with a grinder I can only JUST get my R1 shock on The next step is to use offset cones but that started me wondering about whether the cones should grip the bar or are they stationary in the frame? I don't think I've ever read anything on how the whole assembly is supposed to work I've heard that off set cones will tend the revolve so was intending using a grub screw to locate them in a fixed position....any thoughts?

Cheers

Colin

PS, I think the Atomic would clear the frame on a normally sized barrel, its just that the Avanti is a bit bigger.

[missing lynx]

I've used offset cones for years and never had an issue with them moving out of position

[coaster]

I've used offset cones for years and never had an issue with them moving out of position

That's good to hear, do you do the nuts up tight or semi tight?

[Digger]

I always have tight nuts Colin.

I've used offsets on a couple of engines for several years with no issues.

The only caveat I would add is make sure you get them from a reliable source as I bought a pair from Ebay and the taper was wrong so they didn't fit in far enough. Result was that the engine stayed put without the bar being in place - took a little time to get it to drop!

[HxPaul]

The engine bar is gripped by the cones when tightened allowing the engine to rotate on the rubber of the mounts,it is essential that the rear shocker is fitted and the engine is horizontal BEFORE the nuts are tightened on the engine bar.If the nuts are tightened before the shocker is fitted,when the engine is lifted to fit the shocker strain can be put on the rubber of the engine mounts causing them to fail prematurely.

[missing lynx]

Nuts tight!!

[coaster]

So no need to secure the cones in the frame?

[coaster]

The only caveat I would add is make sure you get them from a reliable source]

I have an ebay pair on their way but who would be a reliable source? I gave up with the Beedspeed site as it wouldn't let me select a method of paymen

[HxPaul]

So no need to secure the cones in the frame?

I dont know if the cones will move,bear in mind that standard cones will fit in any rotational direction and still be in the correct position.
EDIT
If your fitting offset cones,fit the rear shock and cones first and lift the engine into position and insert the engine bar,making sure you dont change the orietation of the cones.Tighten the nuts on the engine bar.

[Storkfoot]

Just to balance this, I tried a reputable set once. Never again. Moved repeatedy. I sorted my issue with a dremel on the manifold though and standard cones.

[coaster]

Just to balance this, I tried a reputable set once. Never again. Moved repeatedy. I sorted my issue with a dremel on the manifold though and standard cones.

Unfortunately I can't take any more off the manifold Paul and my shock is only 295mm.

So if I have this right, the cones should tighten onto the bar so they effectively become one unit. Further tightening will lock the inner sleeves of the mounts to the bar/cone assembly and all suspension rotation is via the flex in the rubber in the mounts? If that's the case then if the cones rotate it must be due to possible wear in the frame or undersized cones?

[byron]

I've got a set of offset cones you can have foc Colin.
they would really be a last resort fit for me.
dare you take any more off the inlet...?

[coaster]

I've got a set of offset cones you can have foc Colin.
they would really be a last resort fit for me.
dare you take any more off the inlet...?

I already took too much off Jarv, Plastic metal to the rescue as temp measure although I'm wondering about some remodelling. Cheers for the offer of the cones, I'll see what the ones I've ordered are like first.

The thing at the back of my mind is someone once told me you shouldn't over tighten the mounting nuts, could have been Tid??

Cheers

Colin

[Digger]

The only caveat I would add is make sure you get them from a reliable source]

I have an ebay pair on their way but who would be a reliable source? I gave up with the Beedspeed site as it wouldn't let me select a method of paymen

Corrado was my saviour.....

[Storkfoot]

Have you tried the shock off your other scoot? (Don't tell me that's an R1 too?)

[Mel K]

Plenty of grease to hold the cones in the desired position. You have to keep the bolt completely still whilst tightening the nuts , then the cones won't move from the position you've set them at , put one nut on the bolt with enough thread showing to get a pair of Mole grips on, thread the bolt through being careful not to move the cones and tighten from the other side whilst keeping the bolt stationary with the Moleys ! Visually check your wheel alignment from behind when done . Never had a problem with this method and had the engine in and out numerous times .

[HxPaul]

If the cones rotate and the engine bar nuts are tight the only thing that can cause it is the angle of the cones must not match the angle of the frame in which they sit,or the gaps on the cones aren't enough and when the engine mount nuts are tightened the gaps close to soon and dont grip the bar.

[coaster]

Have you tried the shock off your other scoot? (Don't tell me that's an R1 too?)

There was no point (although I did compare them) as the other 2 I have are both standard S3 Escort units and are 300mm (5mm longer)

[coaster]

[................Corrado was my saviour.....

He's been mine too on a number of occasions, I'll have a look on his Just Lambretta site

[Storkfoot]

Hmmh, maybe contact RM? Is it totally radical to thnk that maybe he designed it to be solely piston port?