Rigid_EVO fixing oil tank leak on 86-93 sportsters

[benton]

I replaced my 1988 oil tank with the 1994 version since my tank sprung the infamous leak that plagues the 1986-1993 years. The leak is a hairline leak from the front battery mount bracket on the oil tank. I thought I’d say how I did this so that anyone else with this problem can also update.

You can no longer get the HD kit to convert from to the 1994 tank from HD, but J&P carries a battery tray (350-065) that lets you do so (at $95!!) . The tray fits the 1994 tank that I used as well as the 1997 tank. My previous battery tray had lost its strength and vibrated so badly that I had to zip tie the battery to the frame. I didn’t want to mess with this again so I went with the new tray and 1994 oil tank.

The new tray mounts to the oil tank with three bolts instead of two, which is what makes it more stable and keeps it from vibrating. The lower two holes are also spaced wider. The oil tank from J&P only comes in chrome. I didn’t really want chrome but I’ll live with it.

The fit of the tank is excessively tight because the oil tank outlet (1/2”) lies just in front of the main frame support, but it did fit in the end. The top of the tank is against the frame but that wasn't an issue. The tank and tray might as well be part of the frame they are so solidly mounted. The battery tray also fits the 97-03 oil tank and this may or may not be a better fit. If you try it please let us know. The update took longer than I thought, mostly because of fussing with the fit and replacing hoses, but the result is sturdy with no more vibes in the battery and no more leaks.

Here’s some comments for those considering this replacement.
The new battery tray comes alone, so you’ll also need some new hardware:
-a ½”-3/8” brass reducing tee. This is because the new tank does not have a separate outlet for the drain and you have to split it off the tank outlet. I got the tee from fastfittings.com because I could not find this part in town. The one from Home Depot is too small because it’s meant for PEX tubing.
-4 new rubber studs for mounting the oil tank and battery tray along with ¼” nuts and washers.
-I needed two fender washers for the battery rubber stud to space it out appropriately. This worked well.
-3 5/16” course threaded bolts to mount the battery tray to the oil tank along with washers and lock-washers. Of course these got changed from the fine threaded bolts that were in it previously.
-new hoses and clamps, 3/8 and ½ inch for the oil lines and a ¼ inch for the vent line.
-A ½ inch bolt to plug the oil line drain and a hose clamp. You need one with a shoulder or it will leak. I cut off a 2 inch long bolt to do this.
-blue Loctite of course.
-cardboard to line the tray with. The cardboard will outlast your battery. It’s easiest if you cut the cardboard before you install the tray. Paint it black if it bothers you.
-a new chrome ignition cover to match the chrome tank along with 3 new well nuts. You aren’t really going to let the bike go out with mismatched sides are you?

You need to put the ½ inch hose on the tank BEFORE you mount it, as it is a close fit against the frame. The rubber studs will flex to accommodate this and the mounting holes, but you’ll have to push them some to do so. It’s a very tight fit and, again, maybe the 1997 oil tank fits better. Once I got to the point of putting the tray on I found the tray was somewhat forward of the rubber stud. Fender washers on both sides of the rubber spaced it for a solid fit.

Route the transmission vent line and the positive battery cable behind the tray between the bottom two mounts. The negative battery cable goes forward of the mounts. The oil lines run under the starter. The vent line can run outside the starter. The tank out line is a ½ inch that runs straight to the tee with the ½ inch oil drain line on the other end and the middle attaching to the 3/8 tank-to-engine oil line that I ran under the starter. There’s no drain plug on the new battery tray so you’ll have to use a bolt and zip tie the drain line it out of the way. (The 94 year bikes started putting this plug on the right side of the swingarm). The oil lines are actually neater with the new tank setup than they were before because all of the fittings are on the bottom of the tank

[Folkie]

Sounds like a useful write up.

[benton]

UPDATE: The 1994 oil tank developed a microcrack at the 1/2 in oil outlet weld. This is no doubt because this outlet was jammed tight against the frame. I JB welded it until I got a new tank. I replaced the tank with one off of a 1997 that I got from ebay (in black too!). This 1997 tank has the oil outlet placed closer to the front of the tank and the outlet is angled away from the frame. The fit is much better without the frame pushing on the outlet or any of the other tubes. All is good now.

I recommend this upgrade to anyone that has a cracked oil tank on their four-speed, but make sure you use the 1997-2003 oil tank and not the 1994-1996 tank. Yes, the J&P battery bracket is expensive, but it will keep your battery securely in there without heavy vibrations and hopefully save you from yet another cracked tank.

[InjunMike]

I just brazed my '92 at the bracket leak. 6 years now, and nary a drop.

[jharback]

Yeah, I've replaced mine twice over the years. You can also get a very large washer, remove the bracket from the oil tank, weld the large washer to the oil tank where the bracket was then, weld the bracket to the washer.

This gives a bit of added support and helps considerably.

[steve3410]

I just tried to order the battery mount and its been discontinued. So I think this info needs updating.
Steve

[madnss]

Mine is leaking like a stuck hog. Second 91-93 bike to do this on me. I was going to order the tray and go with 97 oil tank, but since it's discontinued I'll just weld it. Any advice on welding the area around the bracket?

[pat h]

Originally Posted by jharback

Yeah, I've replaced mine twice over the years. You can also get a very large washer, remove the bracket from the oil tank, weld the large washer to the oil tank where the bracket was then, weld the bracket to the washer.

This gives a bit of added support and helps considerably.

usually weld a bigger piece 1x1 2x2 formed to the tank then weld bracket to that it helps spread the load better same as jharback said, just a different approche it works really well

[glacialmoraine]

Can you just use the battery bracket from the 94-96 or 97-03 sporty?

[m.breen]

Does anybody have any more ideas for preventing the leaks/cracks/vibration on the '93 oil tank/battery tray. I had my tank braze welded at the tray bracket many years ago with good results, I just took it off, since the bracket broke where it attaches to the battery tray. I also have an unmolested donor oil tank. I'm thinking of reinforcing the donor with braze welding and installing that one. Any suggestions are appreciated. Thanks, m.breen.