998 fuel connectors question

Mr.Duc · #1 (**permalink**) 06-08-2008, 05:28 AM

So I bought these metal quick disconnects off of Ebay and there seems to be a discrepancy between the ID sizes of the line ( see pictures) The stock Y piece has an ID of 3/16 and the new metal quick disconnect is much bigger. Do you think that they just sent me the wrong size?

http://lh3.ggpht.com/MathewKrz/SEteI...JPG?imgmax=512

Old Fart · #2 (**permalink**) 06-08-2008, 11:51 PM

Yes there is a big diameter difference. You'll have to make new fuel hoses. There is no way you can insert the new qd's in the factory hoses. At the factory level the hose is heated to 400F in glycol to soften it then the qd's are pushed in. The new ones are just too big.

Go to an auto parts store and get four feet of 3/8" fuel injection hose. Also get eight hose clamps. DO NOT get the typical worm gear type clamps. Get the band type clamps with the screw and captive nut. These as you will see have a smooth band that encircles the hose the full 360 degrees that will not cut the hose as worm clamps will. At NAPA these cost $4 each.

Remove the fuel line assembly and the distribution block on the bottom of the airbox. Make your new hoses and you're in biz. While you are at it, get 4 feet of thin mylar coated Nomex firesleeve to cover the new hoses. This will prevent vaporlock on hot starts.

*Note that the barbed fittings on the distribution block are of the smaller diameter as were on the original plastic qd's.
Yes even though you will bottom out the new clamps (two clamps on each hose end) you will be able to twist the hose on the barb fittings. No problem on mine for the past three years.

Mr.Duc · #3 (**permalink**) 06-09-2008, 04:39 AM

That’s the answer that I was looking for….. I have bought some fuel injection line and I need to buy those hose clamps. I tried using the worm gear kind and I was able to pull the distribution block out by hand. I guess the correct clamp makes all the difference. The last thing I want is to see my money pit go up in flames. Anyway, thanks again for the info.

Cheers,
Matt

throttlehead · #4 (**permalink**) 06-09-2008, 05:42 AM

welcome to the races brother man

Old Fart · #5 (**permalink**) 06-09-2008, 02:49 PM

The correct thing would be to drill the existing barbs out of the distribution block and braze in two for the 3/8 hose. Next time I have it apart maybe I'll do that. On second thought maybe I'll get lazy.

Mr.Duc · #6 (**permalink**) 06-09-2008, 05:23 PM

Quote:

Originally Posted by Old Fart

The correct thing would be to drill the existing barbs out of the distribution block and braze in two for the 3/8 hose. Next time I have it apart maybe I'll do that. On second thought maybe I'll get lazy.

thats a great idea or maybe find who makes these distribution blocks and see if you can buy them with a biger barbs. On a side note, I did find a tool that will make you these hard lines. It costs about $200 and its available at Autozone

El Gladiateur · #7 (**permalink**) 06-06-2009, 05:25 PM

Si vis pacem para bellum, a wise man said one day.

So, i'm very interested by this metal connectors, even if i've no issue with my plastic ones.

Is the female metal part a direct remplacement for the plastic one? Do you need a kind of threadlock?

Does someone has pics of this modified "home made" fuel line on a 998?

El Gladiateur · #8 (**permalink**) 06-24-2009, 07:46 PM

Can you find this distribution block (Y shaped part) separately?

Old Fart · #9 (**permalink**) 06-24-2009, 08:05 PM

No you can't buy the block separately. It is a one piece assembly including the fuel lines and the plastic disconnects. Quite expensive......

sburns2421 · #10 (**permalink**) 06-24-2009, 08:21 PM

Could you just run a short section of the larger hose from the new fitting, then a reducing nipple (hose joint?), then the smaller 1/16" hose to the gas tank fitting?

MSC Item Detail

Old Fart · #11 (**permalink**) 06-25-2009, 02:51 PM

Quote:

Originally Posted by sburns2421

Could you just run a short section of the larger hose from the new fitting, then a reducing nipple (hose joint?), then the smaller 1/16" hose to the gas tank fitting?

MSC Item Detail

That would work well. But on a 998 the real estate under the airbox is tight and I think the extra plumbing would be too bulky. The best thing would be to take a 3/8" barb fitting, drill out the originals in the distribution block as there is no check valve or other proprietary devices in there, and braze the new barbs in.

Actually the best approach would be to turn the diameter of the barbs down on the new metal male qd's. This would allow using the existing smaller fuel line. Unfortunately the bore on the metal qd's rules out machining down to the needed ~ 5/16 size.

G8RDuc · #12 (**permalink**) 06-25-2009, 06:59 PM

Desmotimes sells them...$16 each.

Old Fart · #13 (**permalink**) 06-27-2009, 03:21 PM

I got mine from LT. They are the plated brass parts with the barbs sized for the 3/8" line.