Dellorto Carb help on the Caterham
- Broccoli
- Posts: 2172
- Joined: Tue Jul 21, 2020 3:30 am
- Has thanked: 1297 times
- Been thanked: 1241 times
Dellorto Carb help on the Caterham
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!
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!
- Hooli
- Self Appointed Internet God
- Posts: 33543
- Joined: Mon Apr 08, 2019 9:25 pm
- Has thanked: 14345 times
- Been thanked: 11128 times
Re: Dellorto Carb help on the Caterham
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.
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.
Private signature, do not read
- Broccoli
- Posts: 2172
- Joined: Tue Jul 21, 2020 3:30 am
- Has thanked: 1297 times
- Been thanked: 1241 times
Re: Dellorto Carb help on the Caterham
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’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!
- Hooli
- Self Appointed Internet God
- Posts: 33543
- Joined: Mon Apr 08, 2019 9:25 pm
- Has thanked: 14345 times
- Been thanked: 11128 times
Re: Dellorto Carb help on the Caterham
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?
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?
Private signature, do not read
- Broccoli
- Posts: 2172
- Joined: Tue Jul 21, 2020 3:30 am
- Has thanked: 1297 times
- Been thanked: 1241 times
- panhard65
- Posts: 3974
- Joined: Wed Apr 10, 2019 7:18 am
- Has thanked: 156 times
- Been thanked: 4577 times
Re: Dellorto Carb help on the Caterham
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.
1939 Hotchkiss 864
1966 Rover P5 (for sale)
1971 Lancia Fulvia Berlinetta (also for sale)
1977 Dodge 3700GT Hearse
1987 Renault 25 V6 Turbo
2010 Skoda Felica tdi
2013 Peugeot RCZ
2021 Yadea C1S Gay leccy scooter
1966 Rover P5 (for sale)
1971 Lancia Fulvia Berlinetta (also for sale)
1977 Dodge 3700GT Hearse
1987 Renault 25 V6 Turbo
2010 Skoda Felica tdi
2013 Peugeot RCZ
2021 Yadea C1S Gay leccy scooter
- Hooli
- Self Appointed Internet God
- Posts: 33543
- Joined: Mon Apr 08, 2019 9:25 pm
- Has thanked: 14345 times
- Been thanked: 11128 times
Re: Dellorto Carb help on the Caterham
I didn't know Dellortos did that too, I've only ever seen the rings on Mk1 Amals.
Private signature, do not read
- Scruffy Bodger
- TeeShirtFun
- Posts: 5328
- Joined: Mon May 27, 2019 9:18 pm
- Has thanked: 8125 times
- Been thanked: 2423 times
Re: Dellorto Carb help on the Caterham
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?
-
- Banned Grinch!
- Posts: 2344
- Joined: Wed Apr 10, 2019 2:16 pm
- Location: Reigate, Surrey
- Has thanked: 2135 times
- Been thanked: 506 times
Re: Dellorto Carb help on the Caterham
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
I think it's to reduce vibration in the float chambers.
Ben
-
- Posts: 13753
- Joined: Sun Apr 14, 2019 11:24 pm
- Has thanked: 1827 times
- Been thanked: 2712 times
Re: Dellorto Carb help on the Caterham
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.