1981 Yamaha XJ550 with 3.4K Original Miles

Hey Everyone!

I'm new to the forums here and I'm looking for some direction with my new motorcycle.

The guy who owned this previously had a vast collection and as he aged, he started to sell off his collection. Id says this bike is in pretty good condition for its time. I'm looking to replace most of the gaskets and O-rings or any parts past their life span. The interesting thing about this bike is there was a guy who I guess built the motor and removed the old 28mm carbs and put 30mm 2930 AMAL carbs on instead. There is no Airbox, no choke, just the 2 enrichment valves on the carbs. Runs just fine. Looking for an alternative to for the airbox as they don't make cone filters for these carbs.

I started with the removing the fuel system and tank because of sitting rust in the tank and I wanted to clean the carbs. Have not messed with the carbs yet, don't know if I need to. looking for new carb tubing and a fuel hose. Ordered a new fuel cock because this thing was leaking in the off position. Cannot find fuel float gasket anywhere. or whatever the name is. Fuel Cap will leak, need a new seal for that too.

Just looking for help with finding parts and if there are things, I should replace proactively please let me know, I would like to ask those who are knowledgeable and have had experience to point me in the right direction. This will be a very cool bike when I'm done, and I hope to turn some heads ha-ha!

Scroll down for photos!

Best,

Jack

 

That's a fancy little ride you picked up. Someone has done mucho mods to it (besides the carbs), front end off of a ???? (what diameter are the chrome fork tubes?).

 

Thank you for your response chacal. When I get off work, I will take some measurements. This bike is modified, and I believe it is something special. I will also take more in-depth photos.

When you say front end ????, I have no idea what's original on these bikes. I'm unfamiliar with most bikes. I'm better with aircraft LOL.

 

Dual front discs (North American models only used a single disc), and thus fork tube(s) have been changed (as the North American models had a caliper hanger on only one fork tube), rectangular headlight, hard-to-tell but gauge cluster appears to be off an XJ550 Maxim, XJ650 Maxim, or 1983 XJ750 Maxim model, front fender looks very XJ650 Seca-ish or XJ750 Seca-ish.........

 

Here are more photos, hoping to provide a little more context!

Forks are 36mm OD

I made more room in my garage. Looking to sweep up, vacuum and then start pulling more stuff apart. Gotta clean up a bit. I'm going to purchase a service manual. I plan on torque striping and slip marking too.

 

Forks say SHOWA

 

Forks say "XJ750 Seca", since they are 36mm OD and have anti-dive units.......so XJ750R front end with XJ550 Maxim or XJ650 Maxim gauges. "Interesting" is the first word that comes to mind!

By the way, have you verified that it's actually a Seca model (VIN starts with 4U8 or 4U9) or an XJ550 Maxim model (VIN starts with 5K5 or 5K6)? All the bodywork says "Seca" but with as many mods that has been done to it..........

 

The VIN does start with 5K5. I have the original title from 1981

 

Okay, so it's a XJ550 Maxim (explains the gauge set) with XJ750 Seca forks/headlight, and XJ550 Seca fuel tank and side covers. And it looks like an aftermarket Lockhart-style oil cooler.

 

Alrighty, now I know this is not your everyday XJ, HAHA. I'm having trouble finding the gasket for the float in my fuel tank. I think I will just start checking through different years. The only thing I see as an assembly is the petcock and the fuel cap.

 

We have them in stock!


f1) Fuel tank SENDING UNIT MOUNTING GASKET. Molded rubber gasket fits between the sending unit mounting plate and the tank, preventing leaks. A great idea to replace this gasket whenever you pull the sending unit out.

HCP687 OEM fuel tank sending mounting GASKET. Fits all XJ550 Seca, XJ650 Turbo, 1982 XJ750 Maxim, all XJ750 Seca models, XJ1100, and all XS1100 models.
$


f3) Fuel tank Sending Unit mounting BOLTS. These flanged shoulder hex-head bolts attach the fuel sending unit to the tank.

HCP1241 OEM fuel tank sending unit mounting BOLT. Fits all XJ550 Seca, XJ650 Turbo, 1982 XJ750 Maxim, all XJ750 Seca, XJ1100, and all XS1100 models. Each:
$

HCP2745 Aftermarket fuel tank sending unit mounting BOLT, black-oxide coated alloy steel 10mm hex-head bolt has a serrated flange that acts as a lock washer (OEM bolts do not have a serrated flange nor do they use a lock washer). Fits all XJ550 Seca, XJ650 Turbo, 1982 XJ750 Maxim, all XJ750 Seca, XJ1100, and all XS1100 models. Each:
$


But, the gauge set on the bike does not have a fuel gauge, so the sending unit is now a rather vestigal appendage (like tonsils, or your appendix), so if you want to just eliminate it, we have a solution for that, too:


Fuel Sender Block-Off Plates:

t2) Aftermarket tank fuel sender opening BLOCK-OFF PLATE AND GASKET ---- this die-cut metal plate and matching rubber gasket, exactly the same size as the fuel sender opening, allows you to easily block-off the opening in situations where you are missing the sending unit, etc. Each kit contains the block-off plate, gasket, mounting bolts, and sealing washers. NOTE: do not over-tighten the mounting bolts! The aluminum metal block-off plate included in these kits is made from a thinner material than the stamped steel used on original sending units, and do not have to be torqued down very tightly to insure a good seal…..5-7 ft-lbs. of tightening force is more than enough!

HCP2738SET Aftermarket fuel sending unit BLOCK-OFF PLATE AND GASKET. Fits all XJ550 Seca, XJ650 Turbo, XJ750 Seca, 1982 XJ750 Maxim, XJ1100, and XS1100 Standard model tanks.
$

 

This is great news. I was wondering why the harness routed under the tank but was not plugged in. Knowing theres an option for a block off plate with the included hardware is great news. I will purchase that asap. Seriously thankyou!

I made sure to send an email to the parts supplier to see if a few parts are available in stock. Gas cap seal, the block off plate and I was asking about the petcock that i purchased.

 

That is a strange old mongrel ;-) custome footrest hangers too. I wonder who thought of sticking those particular carbs on.?