Solex 44 PA1 Carburettor fuel fittings.

moresparks

moresparks

Well-Known Member
Joined
3 Apr 2007
Messages
208
Location
Westwick - Essex
Visit site
HI,
Has anyone had success in repairing an aluminium thread in a carburettor body?
Whilst laying up the engine for the winter I noticed a slight weep of petrol from the Hollow bolt (Banjo bolt). I have cleaned the fittings and even used stat-O-Seals but it looks like the thread in the carburettor is worn and I cannot fully tighten.
I can get the Hollow screw from our regional Volvo Penta Dealer but if the carburettor top cover has a worn thread, I am wasting money and time.
In an ideal world I would buy a new carburettor top cover but they are just not available. There are two versions of the cover and second hand complete carburettors sometimes appear on auction sites but that will be a gamble. There is not a lot of body to fit a thread insert and some of the thread repair compounds are not compatible with modern gasoline with Ethanol. Hence my problem. I have had conflicting reports regarding JB Weld regarding its suitability with E5 /E10 petrol but that seems like a try ....unless......
Thanks in Advance.
 
Hi – many thanks for your responses.
I have looked at these sites mainly if the top cover was available – without success.
I have not asked for advice though as I just assumed they were spares sellers. Wouldn’t hurt sending an e-mail off though.
One idea I had was that the Banjo Bolt is 10mm diameter but with a fine pitch; I wondered if a courser thread would “re-tap” the thread?
I will persevere as I have twin engines each with twin Solex Carburettors!
 
I wonder what would happen if you dipped the bolt into some epoxy (or similar) and re-inserted it into the hole and let it set. Then unscrew it to see if there was a " thread" (The screw would not be very torqued would it?)

Well here we go! I just did a search on stripped thread repair epoxy and there are lots of different alternatives (including Loctite)

(Sorry, I didn't read the last part of your post. But surely there are some compounds that are compatible with your fuel?)
 
Last edited:
Hi,
I agree, a thread insert “would” be the way to go but there is not a lot of body to drill and fit a thread inset.
At the moment I am trying the JB Weld repair and also testing a small blob in a small container of petrol to check on its longevity. The other option is that it looks like the banjo bolt is 10mm diameter with a fine pitch. I could go up slightly to an imperial size and try re-tapping.
 
Had the banjo threads 'opened out' and re threaded with a tapered thread, fitted compression fittings with same and connected a length of suitable copper pipe between the 2 carbs, elbow on rear, T on front. Put a barb on the front carb ('T' fitting) and replaced the fuel hose from pump to comply with BSSC in my case. Never had a problem after that and the re modelling only cost me 30 quid. This was on a VP AQ130C
 
I’ve had similar problems on Ali castings on fuel filter housings, the best engineering solution is to thread lock a helicoil in as Ali threads are so soft, even if you have little depth as it will make it much stronger as well.

If you retap you could still have the same issue in the future.
 
Hi,
Apologies but dumb question alert.
The current Banjo Bolt is 10mm diameter. Checking drill sizes for a 10mm helicoil and it is probable that I have enough “body” for a helicoil. However what worries the most is that the cover is an awkward shape and the fuel inlet is at an angle; to get the hole lined up perfectly horizontally and vertically is near on impossible despite access to a pillar drill. It is critical (I assume) to get this right. Otherwise I may still get a leak.
So... if I went down to 3/8 helicoil and banjo fitting ... will I get away without drilling but just tapping, starting off with a tapered tap?
 
“Medway Mudlark” I noted your comments and am grateful for your contribution. It is certainly worth thinking about as a backstop (that’s not swearing is it). However as I have a twin carburettor setup this is a lot more involved for me but certainly worth thinking about.
 
When you drill for the helicoil the drill will tend to follow the old thread, I would hold the casting in a vice and hand drill. This is probably easier to line up. Don’t forget the helicoil tap is a non standard size matched to the helicoil. Use stud lock to fix the helicoil and make sure it doesn’t leak. And don’t forget to use new copper washers on both sides of the banjo
The helicoil comes as a set with tap, drill etc
 
You must log in or register to reply here.

Share this page

Top