Service Manuals and Supplementary Service Manuals

[Guest]

Hello, I am going to restore my 86' GS 400 E in the new year and I was looking into service manuals. I see that BikeCliff has provided one but I notice it's for an earlier version of my bike.
Is this going to matter much with restoring the engine for example?

Also, while I was looking for service manuals that fit my bike's year I came across something called Supplementary service manuals on Ebay.

Would this be a good thing to invest in?
I have both Cylmer and Haynes repair manuals for my bike.

Appreciate the tips.
-Andrew

[Burque73]

My shop manual has a supplement page for each change they made to the GS 850 models over the years. I'm thinking If you get only the supplementary manual it may be incomplete for your use unless you have the previously printed pages.

[Rob S.]

The differences between my bike, an '82, and the previous year are mostly cosmetic or stem from cosmetic changes. So the Suzuki Sevice Manual is unchanged, with "supplemental" chapters at the end for two 1982 variants.

Haynes and Clymer are good to have, but try to get the official Suzuki manual (and any supplemental chapters). You could download and print it from BikeCliff (like I did), but that requires a lot of ink, paper and time, and the quality of the diagrams suffers greatly.

[HAMMERHT]

I'm looking at the serv manual provided on the forum and I see that it covers 1981-1983. I've looked online for other manuals that service gs400's that would be newer but I've had no luck so far.
I also notice a discrepancy on data on my GS on multiple websites. The service manual online for example says the engine compression is 10.1:1 but sources online that show stats for my year say 9.1:1. Is this much of a difference?
It's also a bit difficult to find reliable data on my bike since it has the 8 valve twin motor from the GSX line in the rest of the world.

My GS is a Canadian import. It was called the GS 400 S, but the tag on the frame calls it a GS 400 E.

As for printing the manual, a friend of mine who rebuilt his Land Cruiser engine recommended me to go to a office supplies store and have them print it. I've seen his manual and it looks pretty detailed.

[Gorminrider]

You have the Haynes and that's your best place to start.

As you know, the older manuals here (you need two of them by the way-the "large one" for 250-300's and the "smaller" one for 400's) should still be a help where the Haynes is unclear...
I have the Haynes and I use it for my '81s, but I haven't paid much attention to its details on your bike -still they wouldn't use the same manual if they were really much different. Wherever the newer bike is specifically mentioned in the Haynes is the first place to look for differences....where there are none noted, you could refer to the older shop manuals as a help.
The few diffs I know of: your wheelbase is longer, the valve cover is different maybe a more convenenient choke/enricher....but I expect I could put my engine in your bike.

I don't know what Online sources you're looking at but generally, online sources are great for propagating mistakes-they copy from each other. I would trust the Haynes or the shop-manual before online sources. If there's a real difference, it can be tracked back as differences between engines in the Haynes...but I doubt it.

That said, be aware that motorcycles sent to Germany and other countries often have lower hp models...I recall they change the engine timing to accomplish this. Perhaps they even change the cam? where ours are 44hp, theirs show up as 27hp : it's just another thing that confuses on the web...

[HAMMERHT]

As you know, the older manuals here (you need two of them by the way-the "large one" for 250-300's and the "smaller" one for 400's) should still be a help where the Haynes is unclear...

Wait a second, you recommend I get the 250-300 book too? Are the specs similar?
I will look into printing the service manual from GS Resources and buying a supplementary manual too. More knowledge the better, right.

[Gorminrider]

Yes,Hammerht, the 250-300 manual IS the official shop manual for the two-cylinder gsx engines... The smaller 400 manual describes the (few) differences. It seems odd but after all, the same is done in ,Clymer and Haynes and many shop manuals too, except they do it in one book.

Unfortunately, these on BassCliff only cover to 81. I've never found a newer version.

[pete]

Also look into http://www.e-classicbike.com/

I got a re-print of the genuine 450 twins manual from him and it's excellent. No incorrect torque specs listed (both Clymer and Haynes had some wrong).

If he has the right one for your model, well worth it I reckon.

[HAMMERHT]

Thanks Pete.
I did not realize that finding a reliable manual for my year of bike would be difficult.
I found out that my generation of GS/GSX motorcycle was from 1984-1986.
If you know someone who can clarify that the engine specs are the same with other 8 valve GSX 400 motors from earlier years, that would be great.
I read around that my bike is no unicorn, but looking for a manual that covers it makes me think otherwise.

[Gorminrider]

If you know someone who can clarify that the engine specs are the same with other 8 valve GSX 400 motors from earlier years, that would be great.

That'd be your job....unless JohnPark or Mekanix knows(but he's not been 'round lately)

[pete]

I don't believe they're unicorns as such, but that for some reason there just weren't that many around.

My understanding is the heads on the twin cylinder 8 valve 400's are somewhat fragile so maybe they don't survive quite as well as the 4 valve 450's maybe? Those aren't exactly everywhere anymore either, and in fact there are far more Katanas and GSX1100's around where I live than any of the smaller twin GS'. I think I've seen 3 or 4 different GS450's since I rebuilt mine back in 2011 but Katanas seem to be everywhere

[HAMMERHT]

That'd be your job....

Yes, technically.... but I would hope I could get a yes/no answer here, GS Resources is "the" source for Suzuki GS motorcycle info, isn't it?
Unless you want me to struggle for your entertainment. HAHA. Don't worry I'm already looking into other sources. I just don't want to have to mess something up because I didn't do my research.
Like they say "measure twice, cut once."

[HAMMERHT]

That's funny you say that.
Where I live I have actually seen quite a few 400's. Next to none Katana's, although I know there's one Katana 750 for sale where I am.

[Gorminrider]

Yes, technically.... but I would hope I could get a yes/no answer here, GS Resources is "the" source for Suzuki GS motorcycle info, isn't it?
Unless you want me to struggle for your entertainment. HAHA. Don't worry I'm already looking into other sources. I just don't want to have to mess something up because I didn't do my research.
Like they say "measure twice, cut once."

Well, you can do the forum search and see for yourself. Your bike is not so "rare" in Canada, especially in Vancouver, but there's not so much specific on IT, here, in particular. So, who else is here but you to do the intense cross-referencing that might help others?... But indeed your audience is limited - Because:

..Not that many GSX400s show up on THIS forum anyways because...

- it's in English.... beyond Canada, Europe,Japan bought a fair number of these, but I don't think the bike made a huge dent in the Hondas and Yamaha (parallel) twins of the era.

-the yanks didn't get these and they outnumber anyone else on this forum, by far.

-and especially: there's a lot more interest in 4s... because there's plainly a lot of them. In the 70s-80s All the Japanese makers were, beyond 450ccs (Yamaha 650 being a large exception)... I was there. I remember. All my MC friends had 4s.

[Gorminrider]

My understanding is the heads on the twin cylinder 8 valve 400's are somewhat fragile so maybe they don't survive quite as well as the 4 valve 450's maybe?

Well, I can't say so, but there is one old review online that rates the 400,425 then the 45s0 as the Best Parallel Twins in their class, beating all the Honda-yamaha-kawasaki 400-450 ilk.

The GSX variety, they rated 2nd for your very reason... But that's one review. JohnPark thinks the heads crack from the spark-plug. But I haven't seen that across 3 of them.

I don't believe they're unicorns as such, but that for some reason there just weren't that many around.

small Twins, in general, don't abound. The cafe craze has sucked up a large number of survivors perhaps...not all destroyed-the nicest ones are probably pampered in garages somewhere.
And, of course, little twins just wear out quicker..or people upsize, so they pass through a lot of new owners.