The Dark Wob

I really need to do an online search for this, but just in case anyone on here can help, I’ve just started the Caterham to see the issues post shipping…

Just before I had the car sent to me, I had new heads put on that I think may be the cause (top end strip down and stuff no tightened back up once reassembled???)

There seems to be a large gap between the carbs and the block: I don’t want to just wade in and tighten it, but that looks to be one issue. The next is even more pronounced!



A ‘slight’ leak from both carbs. Again, I don’t want to just tighten the big bolt at the end, as it could be that someone has turned the petrol pressure up (an easy access control, just inside the engine bay, as a surprise for me from shipping…)

Any thoughts please before I disappear into a carb rabbit hole on the internet and then out of frustration, just tighten the buggers up, only to have something break on me!

That all looks only hand tight to me, I'd go right around it checking everything is tight.

If those are copper washers on the carb banjos and they still leak the next thing is to re-anneal them. Take them off, heat them red hot with a blow torch or gas hob & drop them in cold water to quench. It softens the oxidisation on the outside so they can deform under pressure to seal the joint.

Thanks. I’ve been too heavy handed in the past and snapped things due to lack of knowledge, so once bitten, twice shy!

I’ll take them off this weekend and heat them anyway. Just need to stay away from the car as I’m doing it, so that fire in a melting plastic car doesn’t happen!

I'd check they are copper first, they might be fibre. I can't really tell from the video, although looking again they seem more of a fibre colour.

I'd be wanting to check everything surrounding the head was tight as it looks like they didn't finish the job so who knows what else isn't secure?

Thanks - good point!

It has been a while since I last played with Dellorto carbs but on the Lotus I had they were mounted on rubber rings which used to give trouble. I actually sent mine to a specialist to sort as I couldn't get the bloody thing to run right.

I didn't know Dellortos did that too, I've only ever seen the rings on Mk1 Amals.

As said, are there rubbers on the gasket between the inlet and the carbs? Can you spray something flammable "carefully" onto that part and see if the revs pick up indicating they are leaking air in?

The carbs are mounted using rubber O-rings. The spring washers under the nuts allow movement.

I think it's to reduce vibration in the float chambers.

Ben

That does seem to be an excessive gap unless they are huge o rings - going by motorcycle standards of using o rings on the inlets anyway.