GT550 Gurus, Please...

[ukfan4sure]

1. Who makes the best repro seat covers? I have a 73 with the diamond pattern and curved logo on the back.

2. Do ALL of the GT550's come with the rubber rings around the gauges? I just think they are ugly and am thinking of eliminating them on my bike.

3. Are the Master Cylinder parts kits different on the cast vs plastic versions?

Thanks!

[Coyote]

74-77 had no rubber rings around the gauges. 380 and 550 gauges are the same for those years. Starting in mid / late 76 the gauge lenses were changed from plastic to glass.

[Alan H]

1. Who makes the best repro seat covers? I have a 73 with the diamond pattern and curved logo on the back.

2. Do ALL of the GT550's come with the rubber rings around the gauges? I just think they are ugly and am thinking of eliminating them on my bike.

3. Are the Master Cylinder parts kits different on the cast vs plastic versions?

Thanks!

1. Not sure over your side of the pond.
2 & 3 lots of info at the link below.

Http://www.oldjapanesebikes.com/mraxl_G ... s/page-109" onclick="window.open(this.href);return false;

Welcome to 550 world. The way isn't always smooth, but it's worth it eventually!

[Coyote]

The cast cup version master cylinder was used on the 73 only. 74 used the plastic cup version. That was retained throughout production in 77. However---------
The MC's were produced by 2 different manufacturers. Missin and Asco. The ones by Asco were not used much in North America, but there was one on my 76 GT550. Parts kits are available for both MC's used. The ones made by Missin are not marked. Asco's have the name cast on the underside.
There is no advantage of the cast over the plastic, except with the plastic cup you can see the level of fluid. The cups do haze and cloud up over the years, but new cups are available. The rebuild kit for yours and all others made by Missin is part # 59600-18824. The Asco kit is part # 59600-33810
Seat covers are a matter of choice. There are dozens to choose from on eBay. As always, cheap junk is cheap junk. Expect spend $50+ for a decent one. 380 and 550 seats are the same. Lot's of ad's say fits GT380, GT550 and GT500.Someone else needs to chime in here as I was told the GT500 seat IS NOT the same cover as the seat for the GT500 is longer (or shorter) by a couple of inches. I don't know if this is fact or not. Someone with a GT500 needs to tell us.

EDIT: I think I was wrong on the Asco MC's. According to the parts fiche they were used on 76 & 77 models.(mixed with Missins). I guess that's why there was one on my 76. Mine was trashed so I bought a new aftermarket MC on eBay for less than the price of a repair kit..

[tunaglove]

I bought a 73 style cover from Pit Replica on Ebay. The cover looks very close to original. It has the correct diamond pattern. Good quality. Good fit. However the Suzuki logo printed on the back is not curved it is straight across. I also got a '69 TC120 cover from them and that is nice too.

[ukfan4sure]

Thanks to all who have replied. I think I just figured out last night that this bike, although very original otherwise, has a replacement engine. The engine number 39104 is not consistent with a 73. My first clue was I could not find any other 72/3's with the 74-up head/ram air assy. I just purchased another head/scoop combo off of a 72/3 and will at least swap that out due to originality.

[yeadon_m]

Agreed, that engine # is a 74 L model
Cheers,
Mike

[Coyote]

I hope your new ram-air shroud fits. The heads on the 72/73 are markedly different for the 74/77 due to the carburetor rearrangement that started with the 74. Does your bike have individual carbs or are the 3 mounted together on a single bracket? That's the dead giveaway. If the carbs individually mounted. the bike is a 72 or 73. If the carbs are mounted to a common bracket, then it's a 74 or later. At least the jugs an head are.
Though subtle, there was a change in the exhausts in 74. They all look the same, but the rear mounting hole is in a different place. It was changed in 74 for increased ground clearance.

[ukfan4sure]

Yeah, this definitely has the 74 engine. It has single carbs, though. My concern is that the boots might be different and I'll have mating problems with the carbs (air leaking). One carb runner isn't tightening up very well.

And yes, the cylinders are different, at least in the respect to the fins. The 72/3 had 3 fins that extend further back to mate up with the head length. It forms a bit of a roof for the carb runners on the earlier unlinked carbs. From what I understand, the cylinders were changed in 74 to provide clearance for the carb contraption which were now linked together. I've seen a couple of pictures where the shorter cylinders were used with the longer earlier head. It looks a bit weird, but its better than everyone noting you've totally got the wrong head and ram air assy. for the model year bike.

[Coyote]

Sounds like a Bitas bike. Bits of this and bits of that. If you have individual carbs, then the jugs must be 72 or 73. Those carbs were not compatible with the 74 and up jugs. They can be made to work, but not without a lot of fabricating and having special rubbers made. Airbox probably won't match up either. How bout some PICS?

[ukfan4sure]

Sounds like a Bitas bike. Bits of this and bits of that. If you have individual carbs, then the jugs must be 72 or 73. Those carbs were not compatible with the 74 and up jugs. They can be made to work, but not without a lot of fabricating and having special rubbers made. Airbox probably won't match up either. How bout some PICS?

OK, now you're scaring me.....

I purchased this bike non-running. The story from the seller (who was sort of a middle-man) was that the bike needed carb work, but it was parked and never fixed. It is indeed a 73 having been produced in 10/72. I didn't know a lot about these and the fact it was a different, later model engine totally escaped me. It wasn't until I got home and started researching the history of the 550's, that I knew something wasn't right. I can tell you without a doubt that the jugs are NOT 72/73. They are flush cut in the rear, just like the 74 model should be to allow clearances for the "new for 74" carb setup. There are no rear extended fins like the 72/3 had.

So now, if what you are telling me is true, I am trying to mate a 72/3 carb setup with a 74-up engine and the jug intake runners are different. This would explain why the runner clamps seem to be as tight as they will go but are still loose.

Oh the hell how I hate Frankenbikes! ARRRGH!!

So now I guess I need to purchase some decent jugs, right? It's not a huge deal except for the fact my instinct always says "never buy a bike that isn't at least running" and I ignored that because.... Well, I'll not get into that.

[GTandcbr]

Suggest you look here
http://www.oldjapanesebikes.com/mraxl_G ... /index.php" onclick="window.open(this.href);return false;
Definitely not the right jugs head and cover. Tank is later so is petrol tap too far forward for year.
Sorry for the bad news. Can be rectified though.

[ukfan4sure]

...... Can be rectified though.

Even the USA's national debt can be rectified, it's just a matter of paying the money!

It's pretty amazing, though. Usually I'm pretty good at knowing when something has been monkeyed with. There is usually some telltale signs such as one component looking newer or different cosmetically. In this case, it got me. These changes must have happened a LONG time ago. To the casual observer, it all looked original.

For instance, if this is indeed the wrong tank, who bothers to go back the original color and go get the correct stripes? Most people wouldn't bother, as those stripes are ridiculously expensive to buy just to put on an old bike. I mean they are worth it NOW because collectability has kicked in, but back when this was probably done, probably not.

I do have one question, though. Didn't the Suzuki logo go to screwed badges with white lettering in 74? This bike still has the candy apple red over chrome lettering indicative of 72/3. Now I'm really getting confused. Maybe the angle of the photo is messing up the perspective of where the petcock is?

Weird.

[jabcb]

I think you actually have the early tank.

If you look squarely at the side:
The petcock on the late tank is at about the midpoint between the end of the Suzuki emblem & the tank/seat surface.
The petcock on the early tank is at about the 2/3 to 1/3 point.

See:

[GTandcbr]

If it helps I have an early tank and the petcock is 127mm forward.
This may help re the tank badge
http://www.ebay.co.uk/itm/SUZUKI-GT550- ... xy039TN2gn" onclick="window.open(this.href);return false;

http://www.ebay.co.uk/itm/SUZUKI-GT550- ... XQeKNTN2eH" onclick="window.open(this.href);return false;
Hope this helps