Hi all,
Could someone suggest a quick fix to a leaky carb? When starting my 1965 OTS the fuel pump wonÆt completely pressurize due to one of my SU carbs leaking from what appears to be an overflow tube. IÆve heard of a sticky float causing this but before I attempt to open things up I though IÆd check with the forum. IÆd like to try a shot at fixing this before a call for a flatbed to my mechanics shop.
Thanks in advance,
Chris
Submitted by caltomare@char… on Tue, 12/02/2003 - 19:22
Submitted by therays@flash.net on Tue, 12/02/2003 - 17:52
Re.: Leaking carb
Chris: Everyone has pretty much said everything. Great description, as always, by Patrick.
I just went through this procedure on my carbs -- one thing to look for: Flooded floats. They're made out of two-piece brass "donuts" and can fill with gas over time. If they're flooded, they won't close the needles, causing overflow. My main jet springs and one of the main jets were also worn out, so one of my carbs was leaking from the bottom, so check to see if you also need new floats.
I replaced the floats, main jets and springs, Gross jets and banjo bolt (alloy) gaskets. Didn't have to remove the carbs from the intake manifold.
While you're at it, do all three and save yourself future aggravation. I highly recommend buying complete rebuild kits, inc. the Gross jet upgrade, from any of the parts shops (XKs Unlimited, SNG Barratt, Welsh, Terry's). Make sure you get all the gaskets too, inc. the alloy ones for the banjo bolts -- they are deformable and need to be replaced. Be sure to check the torque on these -- they're pressure fittings and fuel will spray all over if not tightened to spec. No need for special tools. (Make sure you cut off the power at the battery kill switch before you do anything)
As Patrick says, if you're mechanically inclined, have the service manual and the right parts, it's a relatively easy afternoon job.
Good Luck!
Glenn Ray
'66 E-Type OTS
JAG of Michigan (NC-19)
Submitted by mcload@ev1.net on Mon, 12/01/2003 - 21:56
Re.: Leaking carb
Chris:
Actually, replacing the needle valve with Gross Jets is one of the easiest tasks you could ever perform on an E-Type, and is something that all E-Type owners should do. Many fires can be attributed to a stuck needle valve. So allow me to elaborate
Before you remove the carb parts, go ahead an order new Gross Jets from a Jaguar parts supplier. A Gross Jet is simply a valve that uses a ball on a circular seat. Unlike a needle valve that can become stuck in its chamber, the ball on a Gross Jet cannot. As the float in the gas chamber rises, it will eventually meet a two-pronged fork. As this fork rises, it will push against the small ball, forcing it to seat and stop the flow of gasoline.
In addition to the Gross Jets, I would also order the 3 small seals that go between the reservoir top and the chamber, as well as the 6 fiber gaskets that go on each side of the banjo bolts in the fuel supply manifold.
All of these pieces will become apparent as you take the tops off of the fuel bowls. There are also special seals under the 3 center boltsàkeep these in order!!!
The rest is fairly simple. Drift out the hinge pin on the fork piece and remove the fork. Unscrew the old needle valve and throw as far as you can. Screw in the Gross Jet, not forgetting the little reddish gasket. Re-assemble the fork piece. As the directions will state, use a 5/16ö bolt or drill rod to check the distance of travel before the GJ sealsà.you donÆt want it to shut off too soon, or too late. If you donÆt have a manual that explains this, then you need to add THAT to your order from the parts house as well (get the BentleyÆs Official E-Type manual).
Check the bottom of the reservoir for dirt and/or rust. If itÆs pretty dirty, then you may have an issue with your gas tankàbut thatÆs another problem for another post. (If youÆve never done so, pump out all the gas in your tank and un-screw the sump under the caràit could be full of all kinds of nasty, car stopping stuff!!!)
Reassemble everything and CAREFULLY tighten down the banjo bolts. That reservoir top is very thin and brittle, so just make sure everything is snug as opposed to really tightà.otherwise youÆll break the top. Turn on your ignition and listen to the purr of your fuel pump. When it slows down and hopefully stops, check all the fittings for leaks and drips, and snug up where necessary. Piece of cake!!!
If you do a Google Image search (you know what that is, donÆt you?) for gross jet, youÆll see a photo of one.
Good Luck!
Patrick McLoad
1966 E-Type, Right-hand Drive Roadster
#1E1445
PS: The centre bolt on the reservoirs is actually one of the few Whitworth sized bolts on the car...use a Cresent adjustable wrench.
Submitted by cleavefamily@c… on Fri, 11/28/2003 - 23:17
Re.: Leaking carb
Sounds like a stuck inlet jet that is controlled by the float. Try taping gently with a ball pean hammer on the float chamber. When you get home order some gross jets from the usual suspects and install making sure everything is clean. Replace the fuel filter first. Watch for tiny peices of rubber from rubber hoses - they deteriorate from the inside out - in the bowl. Also look for rust - from the fuel tank? Look for teletail signs of tank rust in the filter. Get a good manual on these carbs. Adjustment of the float after gross jet installation can be tedious for the novice, but easy after the first time. Go for it.
Stew Cleave JOCO Chief Judge'69 E-Type 2+2 and other LBC's
Submitted by mfrank@westnet.com on Fri, 11/28/2003 - 23:08
Re.: Leaking carb
Your carb is overflowing for one of two reasons. Either the needle valve is stuck, or the float has sunk. Either way, you will need to open the offending float bowl to correct the problem.
Mike Frank
Dear all,
Thank you all very much for your terrific advice, my baby is back on the road again as a result of it. A barley sunken float was the culprit. Thanks to your fantastic responses I have a thorough understanding of this part of my car. I hope future repairs will be this easy!
Happy Holidays,
Chris