Twin Carb help...possibly???

[wil]

Hi all - I'm running twin Dell 36's on my stock 1600 with stainless exhaust in my 1971 bay

All has been running fine untill I started her up for the trip to vanfest - where there is a noise, that can only be described in words as, 'sounds like a steam train' comming from the left hand carb.

This apears to have no effect on performance, acceleration or temp & is difinatly comming from the left hand carb

Any Ideas anyone?

I've checked valves = Fine
Sprayed carb cleaner around gaskets & no change in rpm
Exhaust conections checked & fine
Both carbs are sucking the same amount of air - using a flow meter.

The van made it to vanfest & back fine but I want to get this sorted before i take off this weekend for cornwall :shock: as I'm sure it will cause some damgage & £££ if i carry on driving her.

Any help or advice would be great

Cheers

 

[speedwell68]

Is it definitely the carb? I had a similar sound on the way up to VF and on the way back the LHS of the exhaust header fell off because the stud has wound it's way out of the head.

 

[wil]

Is it definitely the carb? I had a similar sound on the way up to VF and on the way back the LHS of the exhaust header fell off because the stud has wound it's way out of the head.

Hi - i've checked all the exhaust conections & they're all fine

Just added spark plugs to my check list to make sure they're in tight

 

[wil]

Update

Did a compression test last night & all seems good
1&3 =115psi
2&4 =120psi


What is 'normal'?

I also used a bit of pipe to pin point the noise & it's comming from the float chamber vent in the top of the carb - I'll try swapping the jets over to see if this makes a difference

Any other sugestions?

Cheers in advance

 

[Guest]

yeah that pretty normal +110 is good

while your there did you check/replace the 'O' rings for the bypass and volume control screws??

 

[wil]

while your there did you check/replace the 'O' rings for the bypass and volume control screws??

The carbs are only 700 miles old since rebuild - I got them off the alfa guy on ebay. Top bloke & the carbs are like new. I checked the 'O' rings & they're all in tack...

this problem is driving me mad. Looks like I'll be going to cornwall in the tent at this rate