head cowling - how close is too close?

[DaveTomo]

As per title, how close is too close? Rapido 225 with a 3.5 mm base packer and a 2 mm head gasket ( 60x110 crank).To me it seems very very close to the frame,the LTH reed has plenty of clearance from the frame.Basically I could just about get a cigarette paper between the head cowling and the frame. Do I need to use offset cones?

[Storkfoot]

https://www.chiselspeed.co.uk/store/product/RLCX89K

[Thackers]

check your engine mounts for perishing also your rear shocker is the right one, i think series 1&2 are different lengths to a G.P unit?

[DaveTomo]

Thank you chaps for your replies

Storkfoot offset cones ordered.

Thackers ,maybe I should have said it's a new build ,new casing,engine mounts etc ,the rear damper is a series 3 Chiselspeed,it's the packer plate and head gasket I had to use to get the port timings.But I know what you mean as have had engine mounts collapse before now and it has given similar symptoms so appreciate your thoughts,thank you.

I will update once I have the offset cones fitted

[bookertmgs1]

I'd have gone down the Casa engine bar route - the one with the flat edge and matching cones

That way you can turn the bolt and see the engine move in relation to the frame & set the optimum position.

[Warkton Tornado No.1]

If it were me, I’d have most likely considered deepening the counterbores in the cylinder head to allow for better thread engagement in any case. The knock-on advantage is that the head cowling then sits lower using the standard length nut. Obviously, even they can be substituted for different length nuts though I prefer to fit an M8 stud & large washer for the head cowling to go onto with a similar washer & M8 nyloc nut on the outside. I believe this arrangement reduces the likelihood of the cowling splitting through vibration as there is a better ‘footprint’. I also tend to fit M5 studs - or screws fitted from the flywheel side - so that the cowling has M5 nyloc nuts holding it in place. This modification will often allow for boggy threads in the magneto housing to still be used without fear of the cowling coming loose.

[DaveTomo]

Update and thank you all for your replies.Offset cones fitted and now have more clearance