Parts dealer says 1981 suzuki gs400 parts discontinued

[joe_den21]

Hi everyone,

I'm really having trouble finding parts to rebuild the top end of my bike. Has anyone come across similar circumstances? are any of the other GS series motor parts compatible?

Thank you for any help.

 

[Cipher]

ummmmm what parts are you looking for specifically? Did you do a lookup on parts fiche sites such as alpha-sports? Some things are certainly not available for an old bike.

ouch alpha sports does not list it. Is this a Canadian spec 400 cc I4 engined bike?

 

[Redman]

[TABLE="class: standard, width: 450"]
[TR]
[TD][/TD]
[/TR]
[TR]
[TD]GSX 400 E 1981
Overall Length: 2,105 mm (82.9 in)
Overall Width: 755 mm (33.5 in)
Overall Height: 1,095 mm (43.1 in)
Wheelbase: 1,415 mm (55.7 in)
Dry Weight: 173 kg (381 lbs)
Engine type: Air-cooled 398 cc parallel twin, DOHC, 8 valves. 44 hp/ 9,500 rpm, 3.7 kg-m/ 8,000 rpm.

Here's more Suzuki GSX400E info.[/TD]
[/TR]
[/TABLE]

 

[Redman]

Huh GS400, 2 cyclinder that was 4 valves per cyclinder.
Huh GS400, not listed on US parts supplier. Maybe was not available in US. (the 450 twin was 2 valve per cylinder).

 

[Cipher]

There was also an I4 that looked nice may be it was a JDM grey import though.

I checked csml a british I think parts site and it has valves and stuff listed as well as quite a number of parts for the twin. Its a GSX but Im sure thats a european name convention.

https://www.cmsnl.com/suzuki-gsx400_model13612/

 

[joe_den21]

ummmmm what parts are you looking for specifically? Did you do a lookup on parts fiche sites such as alpha-sports? Some things are certainly not available for an old bike.

ouch alpha sports does not list it. Is this a Canadian spec 400 cc I4 engined bike?

I have a long list of parts I need. Bottom cylinder gasket, o rings, head gasket, valve guides, cover gasket, valve seal, intake valves, exhaust valves, piston ring sets. I think its an import, I was told by the parts dealer that I have a unicorn, they looked through the microfiche and found the parts to be discontinued.

 

[joe_den21]

I think its an import a parts dealer figure maybe its a 1981 suzuki gs400lx

 

[Cipher]

is it too dark to take pictures?
the label on the frame should provide a good amount of information beyond year. Mine had a big old white circle sticker with a maple leaf so if thats still on the steering head near the year and serial sticker then its a canadian market bike

 

[joe_den21]

Oh yeah there?s a big ol? Canadian sticker I see it now

 

[Cipher]

Oh and btw use the csml fiche to get the appropriate parts numbers then with the oem part number do a lookup for parts on a NA fiche site.
Suzuki used parts bin engineering and according to csml the exhaust valve 1291245410 is also used in the gs 750 of a certain generation and no doubt its used in others as well.
what HO?
[FONT=&quot][h=2]Alpha-Sports[/h][h=3]- Part Number Cross-Reference - Where Used - 12912-45410[/h]

Part Number or Accessory Name​

[/FONT]
[FONT=&quot]

• 1980 SUZUKI GS750ET - CAM SHAFT - VALVE
• 1980 SUZUKI GS750LT - CAM SHAFT - VALVE
• 1981 SUZUKI GS750EX - CAM SHAFT - VALVE
• 1981 SUZUKI GS750LX - CAM SHAFT - VALVE
• 1982 SUZUKI GS750EZ - CAM SHAFT - VALVE
• 1982 SUZUKI GS750TZ - CAM SHAFT - VALVE

[/FONT]
Note this is the list that comes back from the alpha-sports web site so its only going to list US models but you get the point harvest the information you need then look it up. If its still listed aas available go to your parts dealer online or local and present him with a list of what you need.

Also note that for some reason the lasat time I bought local the parts fiche in use by the dealer had only US spec parts listed for my bike so I got the wrong jets for my carb off by one size increment. It seems that they subscribe to a one size fits all service. The actually fiche as supplied to dealers in Canada would have correct information.

 

[GregT]

It's most unusual to need valve guides on the 8V 400 twins. The heads usually crack long before the guides wear enough to replace.

 

[joe_den21]

took me a while to figure out how to get a pic on here

 

[joe_den21]

says its a GS400L

 

[joe_den21]

says gs40x on the case

 

[BigD_83]

Definitely an L. There was one of those being piloted by someone who works at my local golf club. Haven't seen it in awhile, however.

 

[GregT]

Engine parts are rest of world GSX400. All same, L, S, and E.

 

[Sandy]

Contact.Murray or Aaron at Modern Motorcycles in Vancouver. They could possibly have the largest stock of NOS Suzuki parts in the world. Just google them. And your bike is not a unicorn, the US imported 2 valve.model for.those years is. Everyone else got the 4 valve.model.

 

[Guest]

Contact.Murray or Aaron at Modern Motorcycles in Vancouver. They could possibly have the largest stock of NOS Suzuki parts in the world. Just google them. And your bike is not a unicorn, the US imported 2 valve.model for.those years is. Everyone else got the 4 valve.model.

I think Murray ran dry a few years ago; we were down to piecing together a complete[ish] gasket set. I think Suzuki Canada may have a few bits left, but I decided to move on and convert mine to a 450. That involves replacing everything above the crankcase....

As Greg says, check the head for cracks from the exhaust seat to the plug hole. I've come to the conclusion that 4 valve heads and air cooling were a bad idea.

 

[GregT]

As Greg says, check the head for cracks from the exhaust seat to the plug hole. I've come to the conclusion that 4 valve heads and air cooling were a bad idea.

Only the early small capacity engines seem to have this problem. The GSX400, the Yamaha TX500, the Honda CB250RS all do it. I suspect the designers were simply a bit miserly with material thickness in the heads. The bigger engines from the same period - the GSX750 and 1100 Suzukis and the 750/900 Hondas have no problems. Pity really as the small capacity 4V/cylinder engines are sweet running units.

 

[Guest]

Only the early small capacity engines seem to have this problem. The GSX400, the Yamaha TX500, the Honda CB250RS all do it. I suspect the designers were simply a bit miserly with material thickness in the heads. The bigger engines from the same period - the GSX750 and 1100 Suzukis and the 750/900 Hondas have no problems. Pity really as the small capacity 4V/cylinder engines are sweet running units.

I differ on this. There is no viable heat path for the web between the exhaust valves. Down leads to the combustion chamber and up leads to the floor of the cambox. You can see the hot spot inside the head where the oil has cooked just above the web. The web is a thermal disaster in waiting as it picks up exhaust heat and has nowhere to put it. I doubt that miserliness had anything to do with it, other than that four pipes would have been complicated and costly.

Valve seat gets hot, expands and cracks head on hottest side - toward plug. Give me a hemi that, while it may be old school, blows intake at the exhaust valve, and has a valve angle that allows for finning on top of the combustion chamber. And don't try to sell me a SOHC design that puts a cam where those fins should be.

One way to deal with it is to run two exhaust ports rather than siamese the port. Even the old XL250/350 did this. SP250 also, I think. The bigger motors are a different situation because you can't hold them wide open for all that long. For those that did, the oil cooled GSXRs did okay at dealing with it, but water works best.

There are also no fins worthy of the name on the top of the GSX400 combustion chamber. I'm currently working on a 1949 Velocette MAC 350 [hemi] which has an iron head but the whole shebang is finned.

Sure, lots of designs run anyway, but I'm into design elegance. The original Aermacchi cylinder head was a paragon of cooling strategy and facing into the wind, much like Moto Guzzi singles. Some pinhead redesigned the head with an 'ashtray' valve cover which was a disaster for cooling, totally eliminating the internal finning. Competition bikes retained the original design - who knew? - and the consumer bikes cooked themselves. Form can follow disfunction.