1991 Suzuki Katana 750 - known problems?

I'm looking at buying a 1991 Suzuki Katana 750 in non-running
condition. The owner thinks it has electrical problems. I haven't seen
the bike yet (other than a picture). Are there any known major
problems with these bikes? Thanks.

Wade

 

Valve clearances burn out early if you're not super-religious with
checking them. The electrical problems are legion: charging systems,
right from alternator, through reg/rec, to battery. Everything
fritzes.

Their electronic ignition systems aren't the strongest, either. If the
rev counter (elecvtronic) starts doing odd things, CDI failure usually
follows.

If I were you, I'd avoid.

 

Hang about - is this the air-cooled version with the pop-up headlight?
Or the fully-faired water-cooled one, which uses a detuned GSXR lump?
Designated GSX750F?

In the UK, the water-cooled one was never badged 'Katana', but I dunno
about the US.

If the former, then everything I wrote applies. Just avoid.

If the latter, then as Albrecht says, they're pretty solid, but avoid
anyway.

 

He's asking $850 for it, and the picture looks good. I'm going to
check it out tonight. If I don't see any signs of life from the
electrical system, I'm going to pass, based on the responses I've
received.

I have enough other projects to work on anyway. I have a 1974 Suzuki
GT185 that I picked up very cheap, and looks to be complete, other
than some minor bits. I also have a 1980 Yamaha XS650 Special waiting
for my attention. Same situation as the Suzuki. I also have some work
to do on my regular ride, a 1980 Suzuki GS750.

I'll post what I find out when I see the bike tonight. Thanks for the
info.

Wade

 

This is the air-cooled version. It does have the Katana name on the
side of the fairing. Thanks.

Wade

 

In which case, ignore everything Albrecht posted, because reading from a
parts fiche, even if you do manage to get the right bike (and he
didn't), is no substitute for experience. To be fair, yours must be one
of the last air-cooled ones they sold.

The air-cooled GSX series (they called the 4-valve heads TSCC, for Twin
Swirl Combustion Chamber) had some good points, but basically it was
Suzuki's first major foray into 4v heads, and the bikes did not shrug
off neglect.

As I posted originally, they are very prone to burning out valves if you
don't check the clearances about every 3000 miles. Do that, and the top
ends last.

The electrics are, as I said, the real problem area. Air-cooled GSX
bikes are a byword for ignition and charging hassles.

 

Wise, but I wouldn't even bother going to look at it.

 

Oh - the GSXF model was oil-cooled, a la GSXR. My slip.

<Googles>

They were dubbed Katanas in the US, but not in the UK.

Well,if it's air-cooled, it's crap. If it's oil-cooled and faired, it's
as Albrecht describes - good bike, but still avoid one with issues.

 

I thought it was air cooled when I saw the pictures (I saw fins on the
cylinders), but when I actually saw the bike, I saw the oil cooler and
oil lines. It does have the full fairing.

The owner said that it ran fine when he parked it last fall, but
wouldn't start when he brought it out this spring. The oil light and
neutral light came on with the switch, but nothing else (brakelight,
turn signals, headlight, etc.). He said he removed the starter to test
it, and it worked when powered directly from a battery.

Didn't buy it yet, still thinking about it. It is in nice shape for a
1991.

Wade

 

And which part of "Oh - the GSXF model was oil-cooled, a la GSXR." did
you not understand, then?

And this is the engine you slagged off as being unreliable, remember.
It's the old Gixxer lump.

 

Lemme get this strait..

There is a guy that wants to sell you a lump of metal that
once was a motorcycle... Right??

Lemme tell you some stories I heard when I searched
for a bike.

'You gotta run it at least half an hour on choke"
Reply on me complaining that I couldn't find any of the 100 plus
horses the bike (1100 cc!) used to have.

"Sounds like a Harley, doesn't it?"
Right buster. That rotten exhausts will cost me more
than what you ask for this piece of crap.

"The mirrors came off when I shove it out of my shed
yesterday".
Right. And at the same time you bent the front fork?

"I don't understand why it doesn't start. Yesterday it
ran fine"
Sighh....

"I love this bike. It served me well for over 10 years."
Pardon me, why does the official (on_the_web) registration
tells me you only owned it one month?

I did not make these stories up Wade. They were
really told when I searched a bike via 'marktplaats.nl"

In short: "That bike does not run. You have neither seen,
nor heard, nor tested it.

Even if it once was the most reliable, "always runs",
"lastst forever"....

Forget it.

Rob.

 

Run away, run away!

If it were me, and I had an unlimited amount of time (I don't) and space (I
don't) I'd offer him $100 for it unless he can get it running. Figure you
can part out the bike on eBay and recover your money if it's junk. If it
don't start, there's NO WAY you can tell what's wrong with it and by this I
mean how much it's going to cost you to fix it.

"Electrical problem" could be the ECU which is likely either a) unavailable
from suzuki or b) around $1,000 for a new one.

Like I said, run away if you're looking for something you can ride.

Dave S

 

After considering all the advice, I decided to buy the bike anyway.
Why? I assessed the bike's condition, and figured that in the worst
case, I could get my money back from another (stupid?) soul if I
couldn't get it to run. It is in good physical condition for it's age,
the tires are good, and the battery was up. It is missing some small
hardware here and there (fairing mostly).

I managed to get all the lights, turn signals, horn, and starter
working on Saturday after cleaning the corrosion off the fuses and
then properly connecting the wires from the gas tank sending unit. It
would crank, but not start. I saw the it was getting fuel, because the
plugs were wet. I checked for spark, but only got a very weak one.

Monday I bought new spark plugs, but it still would not start, and I
saw no spark. I decided to read the manual (included with the bike) to
get some troubleshooting info. Checking the coils looked like a good
place to start.

Tonight I checked the resistance of the coils, and they looked good. I
was inspecting the wiring under the gas tank, and saw a wire
unplugged. I found the other wire, plugged it in, and tried to start
it. It fired once, so I stopped to put the gas tank back on (it was
sitting on a bucket beside the bike, with the wires plugged in). A
couple seconds of cranking it, and it fired up. It sounds strong, and
takes throttle with no hesistation. It idled (if you can call it that)
at about 3,000 rpm. I let it warm up, but the idle did not go down,
and actually went up about 1,000 rpm, with a little backfiring when I
back off the throttle.

I haven't tried to put it in gear yet, partly because I didn't have
the tank and bodywork back on, and also because it is idling so fast.

I'm feeling much better now. I thought everyone might like an update.

Wade

 

This is all interesting for an amateur like me. Not to prolong the time
it takes you before you are riding it, but I look forward to hearing any
carburetor adventures you have on the way there. I hope you'll post
updates.

p

 

Sounds like a result.

 

I know that, I do it for charity ;-0

But seriously, as I'm sure you're aware any type of electrical problem on
these bikes can be a whore to diagnose and fix and is often costly
especially with newer bikes. I didn't think I was being particularly
negative, more like realistic.

I often whip off dickheaded notes which waste readers' time with useless
criticisms like yours above and regret it later. This is probably one of
those times, but then that's half the fun of usenet, isn't it?

Dave S.

 

Look, the early GSX bikes were prone to electrical problems. You know it, I
know it. For MOST PEOPLE, and in particular people like the OP who APPEAR
(remember, all we have to go on is what's in the post) to know NOTHING about
motorcycle mechanics, it would SUCK to buy a bike which requires major work.

Do you know how many people have bought vehicles from a seller who advised
"yeah, it makes this noise but it just needs the valves adjusted" or
something similar? Like "it ran perfectly when I put it away in the fall".
It happens all the time, it's happened to me before I had any idea what I
was doing. BTW I've been doing all of my own vehicle maintenance for about
twenty years and riding bikes longer than that, I believe I've got something
to contribute. If you don't, **** off. You don't have to read it and you
don't have to criticize me personally when you disagree with that I've said.
How exactly am I "pretending to be somebody I'm not"?

My _SINCEREST_ apologies for trying to be helpful. And I'm REAL sorry I
don't have ALL FUCKIING DAY to look at schematics on bikebandit.com and
advise the liberal use of "Berryman B12 choke and carbeuretor cleaner" or
berate posters for not using the phrase "enricher" instead of "choke".

All I said was that without knowing what was wrong with it, there was a fair
amount of risk involved, and like many other posters, indicated that _I_
would walk away. Even before I tried the Berryman B12.

It's really too bad all you have is this newsgroup. Obviously you've
invested so much into it that you actually get ANGRY when someone dispenses
any type of advice with which you disagree. You contribute a lot to this
newgroup, but have no god-given right to be such a sanctimonious
self-aggrandizing prick.

Can you say "get a life"?

No, read my post, you've got the time. I said "could be the ECU", What I
meant to convey was that in a worst-case scenario (you know, the kinds of
situation which might cause somebody to sell their $2,500 bike which worked
perfectly in the fall for $850) the repair was POSSIBLY going to cost a
significant amount of cash. For me, spending $500 on an ignition module for
an $850 bike seems like a lot. One might even say almost 60% of the price.

Yeah, and maybe you'll get your arrogant dick slammed in a car door. that's
YOUR karma.

Have a great day.

Dave S.

 

After considering all the advice, I decided to buy the bike anyway.
Why? I assessed the bike's condition, and figured that in the worst
case, I could get my money back from another adventurous (stupid?)
soul if I couldn't get it to run. It is in good physical condition for
it's age, the tires are good, and the battery was up. It is missing
some small hardware here and there (fairing mostly).

I managed to get all the lights, turn signals, horn, and starter
working on Saturday after cleaning the corrosion off the fuses and
then properly connecting the wires from the gas tank sending unit. It
would crank, but not start. I saw the it was getting fuel, because the
plugs were wet. I checked for spark, but only got a very weak one.

Monday I bought new spark plugs, but it still would not start, and I
saw no spark. I decided to read the manual (included with the bike) to
get some troubleshooting info. Checking the coils looked like a good
place to start.

Last night I checked the resistance of the coils, and they looked
good. I was inspecting the wiring under the gas tank, and saw a wire
unplugged. I found the other wire, plugged it in, and tried to start
it. It fired once, so I stopped to put the gas tank back on (it was
sitting on a bucket beside the bike, with the wires plugged in). A
couple seconds of cranking it, and it fired up. It sounds strong, and
takes throttle with no hesitation. It idled (if you can call it that)
at about 3,000 rpm. I let it warm up, but the idle did not go down,
and actually went up about 1,000 rpm, with a little backfiring when I
back off the throttle.

I haven't tried to put it in gear yet because I didn't have the tank
and bodywork back on.

I'm feeling much better now. I thought everyone might like an update.

Wade

 

And there, we can agree to disagree.

 

You are one piece of work. Sheesh!