Hi,
I would like to know how the gearbox in a GSX 1400 should typically operate. I have one with 90,000 km on the clock, and I am a bit concerned about how the transmission feels.
First gear engages very hard and loud – which I understand is quite normal for these bikes – but the subsequent upshifts are also very loud and clunky.
The clutch seems to be working properly, at least at a standstill. The motorcycle starts moving when the lever is released to about 3/4 of its range, and there are no fluid leaks or air in the system. As for the gears themselves, they all engage fine and don't pop out while riding. The only issue is those very harsh, loud noises when shifting.
When downshifting with rev-matching, I occasionally manage to avoid the clunk. Interestingly, the smoothest shift happens between first and second gear when the engine oil isn't fully warmed up yet.
I have a feeling that something might be wrong with the clutch itself, as if it's not disengaging completely. However, as I mentioned, I haven't noticed the bike creeping forward when the clutch lever is pulled in.
Any advice or insights would be greatly appreciated.
Best regards,
Hi Maanieek, welcome to the forum. We prefer new members to do a bit of an introduction to the group in the intro section here: https://gsx1400owners.org/forum/index.php?board=20.0 Have a read so you get the idea.
Now as for the clunky gear shifts, you probably have hit the nail on the head here when you say the smoothest shift is 1st to 2nd shortly after start up before the oil has warmed up. To me, this is your smoking gun, the oil. What oil are you running in it? Not trying to baby it with Full Syn are you? or Motul 7100?
G'day mate and welcome to the nuthouse. Normally I wouldn't respond until you introduce yourself. Thanks Col.
I think you should buy some professionally fitted earplugs and all that noise will miraculously disappear 😎.
They're old school motors and are designed to last, not be smooth or quiet. Trust me my bike is as noisy today as it was 25 years ago. 🕐
I'm on my 4th GSX1400 now and I haven't had noisy gear changes on any of them. On this last one the clutch does feel a little bit heavier than I thought it should. I also think it is mostly down to what oil you are using. My bike is going in for a full service and check over next week.
Gday Maaniek, looking forward to your introduction.
Have you tried holding the clutch in for a count of 10 and rolling the bike forward then select a gear?
I'd also suspect the oil, the clutch plates can stick together if the oil isn't thick enough, this then gives the feeling of a partially releasing clutch. The above check allows a bit of time for the plates to separate.
Also check the slave cylinder for correct operation, and clean the push rod that goes through into the engine. A popular mod is to fit a hayabusa slave cylindervseal, this stops crud from going into the slave and onto that pushrod.
Also check lever at the perch, the small bronze bushing in there can wear out, but it seems like you've got full range of lever travel as the bike doesn't creep fwd.
Change the oil to a semi sun 10W40 JASO MA2 spec and she'll be right
I have a few big Suzuki's, it's pretty normal to feel / hear the bike going into first from neutral on most of them. It's just normal to me and not a big deal.
Up or down through the gears is a lot less defined and harsh.
Personally the biggest downside to many big Suzuki's for me is the BTL / Back Torque Limiter / poor version of a slipper clutch which does riding no favours at all.
Clunk into first is normal, every 4 cyl jap bike I've owned same. I hardly touch the clutch changing gears,changes fine for me🤷🏼 Change the oil, ear plugs, practice a bit more👍
I found mine quite clunky, rebuilt the slave cylinder once and it helped a bit but then changed it out the an Oberon slave cylinder, much improved
Quote from: Phill P on Saturday, 12 September 2026, 06:16 PMI found mine quite clunky, rebuilt the slave cylinder once and it helped a bit but then changed it out the an Oberon slave cylinder, much improved
more progressive feel or lighter? Can you give some detail on the improvements at all? Im thinking of doing the Oberon upgrade as well.
Quote from: Eric GSX1400K3 on Saturday, 12 September 2026, 06:51 PMQuote from: Phill P on Saturday, 12 September 2026, 06:16 PMI found mine quite clunky, rebuilt the slave cylinder once and it helped a bit but then changed it out the an Oberon slave cylinder, much improved
more progressive feel or lighter? Can you give some detail on the improvements at all? Im thinking of doing the Oberon upgrade as well.
Slightly lighter although I did fit new lines and fluid at the same time, definitely smoother, wouldn't say more progressive. Definitely better than before, although a brand new normal slave cylinder may give the same result :whatever:
Yes, you're right—I used Motul 7100 15W50. Even so, I wonder if clutch wear at this mileage might be the cause.
With the motorcycle raised on the center stand, try changing gears.
Clutch state: You should be able to stop the wheel with your foot.
Quote from: maanieek on Saturday, 12 September 2026, 09:57 PMYes, you're right—I used Motul 7100 15W50. Even so, I wonder if clutch wear at this mileage might be the cause.
Ok, pretty sure that's it. These engines don't sound good on 7100, there have been other members who were using the same oil, thinking they're looking after the internals better by using Motul 7100, but it's noisy and clunky. Change your oil to a semi syn 10w/40, probably the cheapest you can find and try that. Now doing an oil change never gets out all the oil, so you'll still have about 1L of 7100 in there, so don't be surprised if it's still a bit clunky. Do a 2nd change to get all of the 7100 residue out and fill with a good semi syn 10w/40 and see how it sounds and feels then. It's 1 oil filter and 2 packs of oil to try, so not that expensive really.
Okay, if it's not too much trouble, let me know what oil you use. I'll give it a try.
Well, living in NZ, I use Gulf Western Synex 3000, but doubt you'll have that available in Poland. I know a lot of the UK guys use Halfords? Is that one you have?
Amazing Col, picking what oil in his bike.
LOL, KC the oil whisperer! :happy1:
Maanieek, I see they sell Fuchs Silkolene in Poland. That was oil of choice in the past for a lot of Europeans on this forum. Super 4 10w40. Expensive here in Oz.Just a thought🤷🏼
Quote from: grog on Sunday, 13 September 2026, 02:01 PMMaanieek, I see they sell Fuchs Silkolene in Poland. That was oil of choice in the past for a lot of Europeans on this forum. Super 4 10w40. Expensive here in Oz.Just a thought🤷🏼
That is what I have always, used in mine and never, had any problems with it. :onya:
Back in old org days, around 2012, i spent ages trying diff oils in my 14, just for info to others. Hard to remember results, could basically only go by gear change smoothness/clutch action. Remember Motul was dearest and worst. Gulf Western good, Silkolene good but 4litre bottle, more money for extra 1litre needed.Valvoline was good, Reckon i tried 5 or 6 brands but all results lost when old org disappeared. One i remember was Motul clutch action, turned easy friction point into on/off. All just IMO.
Any semi synthetic 10w40 is ok, just check that it's JASO MA2 rated.
always use a mixture of 10W40 amsoil with redline.
In lubricants I never look at the price and if don't do much city work extend the change to 18 months given the 'excessive' quality of both, the base oil (PAO+ESTER) and the very excellent additive package
You can try a 20W40 to have wetter gears.
But that takes away some upload speed at boot time
Always good to remember when you do an oil and filter change on bikes like the 14, be it for a refresh or to try a different thee, just how much of the old oil you are leaving in there. More than a lot of folk realise.
Oil change is less than an oil and filter change, which is less than a drained oil cooler change, which is less than a dry build.
It's quite common on some Suzuki's to have close to a litre still in the motor with an oil and filter change. An oil and filter change can leave 1/6th of the old "dirty" type still in there.
Quote from: Tony Nitrous on Monday, 14 September 2026, 09:34 AMAlways good to remember when you do an oil and filter change on bikes like the 14, be it for a refresh or to try a different thee, just how much of the old oil you are leaving in there. More than a lot of folk realise.
Oil change is less than an oil and filter change, which is less than a drained oil cooler change, which is less than a dry build.
It's quite common on some Suzuki's to have close to a litre still in the motor with an oil and filter change. An oil and filter change can leave 1/6th of the old "dirty" type still in there.
So is there any way to get rid of most of the old oil. Or is it just flush and repeat and hope you got most of it out.
You can crack the pipe connector to the oul cooler,but risk leaking from there forever after. Most dont bother and just rely on frequent oil changes every 5000km or 12 months (monthly in Hooli's case, 12years for Notty)
The oil that goes to the radiator is that of the lubrication circuit.
If the radiator is emptied, there will be long moments in which what reaches the lubrication areas is air, pure air.
and so on until the end of the circuit..........air pushed by the oil
Quote from: Barbastro K6 on Monday, 14 September 2026, 07:43 PMThe oil that goes to the radiator is that of the lubrication circuit.
If the radiator is emptied, there will be long moments in which what reaches the lubrication areas is air, pure air.
and so on until the end of the circuit..........air pushed by the oil
No.
The oil pump produces more pressure & flow than is needed, the excess that is released via the pressure control valve returns to the sump via the oil cooler. The lubrication circuit isn't affected.
ok, control maximum pressure......but the air is still there until the end of its journey through the lubrication circuit.
there is no cause-effect relationship
https://www.youtube.com/watch?v=-WgUuU13C3g&list=RD-WgUuU13C3g&start_radio=1
Again, No.
That's not how the oil circuit works on the 14.
I can't be bothered to watch the video as I understand how the engines I own work & I've seen the layout of what I'm talking about when I had the sump off one of them.
The oil flow circuit is shown in the manual, afaik its vented into the crank case and breather via the airbox. No risk of running with no oil as long as the pick up is below the oil fill level, so in a nutshell you can drain the oil cooler if you want, then fill as normal and run the engine. May need to fill more than the std 4.2l oil change volume though.
Quote from: Eric GSX1400K3 on Monday, 14 September 2026, 07:37 PMYou can crack the pipe connector to the oul cooler,but risk leaking from there forever after. Most dont bother and just rely on frequent oil changes every 5000km or 12 months (monthly in Hooli's case, 12years for Notty)
Do the oil pipes tend to leak after draining the oil cooler as I was thinking of doing this on the next oil change .
Paul
Quote from: Phill P on Tuesday, 15 September 2026, 12:18 AMQuote from: Eric GSX1400K3 on Monday, 14 September 2026, 07:37 PMYou can crack the pipe connector to the oul cooler,but risk leaking from there forever after. Most dont bother and just rely on frequent oil changes every 5000km or 12 months (monthly in Hooli's case, 12years for Notty)
Do the oil pipes tend to leak after draining the oil cooler as I was thinking of doing this on the next oil change .
Paul
No, it's sealed by an O-ring. I've never had one leak after disturbing it. Just make sure you don't trap any dirt under the sealing face or on the o-ring if/when you drop it as it falls out of it's slot.
Quote from: Hooli on Tuesday, 15 September 2026, 12:35 AMQuote from: Phill P on Tuesday, 15 September 2026, 12:18 AMQuote from: Eric GSX1400K3 on Monday, 14 September 2026, 07:37 PMYou can crack the pipe connector to the oul cooler,but risk leaking from there forever after. Most dont bother and just rely on frequent oil changes every 5000km or 12 months (monthly in Hooli's case, 12years for Notty)
Do the oil pipes tend to leak after draining the oil cooler as I was thinking of doing this on the next oil change .
Paul
No, it's sealed by an O-ring. I've never had one leak after disturbing it. Just make sure you don't trap any dirt under the sealing face or on the o-ring if/when you drop it as it falls out of it's slot.
Cheers, I'll go ahead and do this on the next oil change :cheers:
Quote from: Eric GSX1400K3 on Monday, 14 September 2026, 07:37 PMMost dont bother and just rely on frequent oil changes
Absolutely.
Frequent oil changes are by far the best way, even though an oil cooler draining would be a help (I never do) you are never going to get ALL the old oil out. If you are super fussy about your oil (I'm not and I've never had a drama) then regular or more frequent changes is the easiest way to help get the old stuff out.
I have run a few bikes to the book, 12000K's / 7,500 miles / warranty service recommendation, and have never had issues, but I do feel more comfortable doing them a bit sooner.
All mine run the same oil, so an oil / oil filter is always mixing same with same. I'm not using an oil change to change the grade of "most" of my oil.
Can of worms, but I just thought it was worth a mention as to how much most folk don't change.
Quote from: Hooli on Tuesday, 15 September 2026, 12:35 AMQuote from: Phill P on Tuesday, 15 September 2026, 12:18 AMQuote from: Eric GSX1400K3 on Monday, 14 September 2026, 07:37 PMYou can crack the pipe connector to the oul cooler,but risk leaking from there forever after. Most dont bother and just rely on frequent oil changes every 5000km or 12 months (monthly in Hooli's case, 12years for Notty)
Do the oil pipes tend to leak after draining the oil cooler as I was thinking of doing this on the next oil change .
Paul
No, it's sealed by an O-ring. I've never had one leak after disturbing it. Just make sure you don't trap any dirt under the sealing face or on the o-ring if/when you drop it as it falls out of it's slot.
I bought a packet of O-rings.
Guess who has to get the oil filter out from behind his Yoshi Cycline full system.
Oil n filter every 5 thou k. Not at all concerned about what doesn't come out, pretty much same deal every machine made. 🤷🏼
If the oil that goes to the radiator had a simple circuit going to the radiator or to 6 in yectors at head and after returning to the carter, then the radiator could be drained without any problem.
But it's not like that.
There are two oil circuits: one that only sends oil to the 6 injectors in the cylinder head and another that lubricates the entire system AFTER passing through the radiator.
I add explicit text taken from the manual of the French publisher ETAI (page 5) and that I proposed adding to manuals here:
The well-known patent, on which the legendary robustness was built
GSX-R "SACS" engines, is renewed; namely a circulation
oil forced and fed by a double body oil pump, which
is driven by a pinion placed behind the clutch bell.
One of the pump bodies provides lubrication for the motor and the
gearbox as well as oil cooling, via a radiator mounted
facing the road and equipped with a motorized fan controlled by a thermal
monocontact, while the other is used exclusively for cooling the cylinder head, for which particular care is always taken.
For this purpose, the total oil capacity has been re-evaluated by more than one
liter (5.7 l. compared to 4.6 on the 1200)
Quote from: grog on Tuesday, 15 September 2026, 04:42 PMOil n filter every 5 thou k. Not at all concerned about what doesn't come out, pretty much same deal every machine made. 🤷🏼
Exactly.
I do 4k miles as the 5 thou k works out at just over 3.1k miles & that just seems too low to me. 4k is easy to remember & add to the mileage to know when the next one is due as well.
Quote from: grog on Tuesday, 15 September 2026, 04:42 PMOil n filter every 5 thou k. Not at all concerned about what doesn't come out, pretty much same deal every machine made. 🤷🏼
Yeah, same here.
My post was only really aimed at those who think it's out with the old, in with the new and they had totally changed to another brand or all fresh.
19 years on my B-King, and never once have I made the effort to drin the oil cooler, or my Busa's. It is what it is.
5000km oil and filter changes for me. Finding a brand of oil that you like makes a world of difference to gear changes. I used $160 worth of high performance oil early on hoping to improve gear changes, I couldn't drain it out fast enough. So it's not always the most expensive oil that gives the best results. As for engaging 1st gear, don't tickle it, stand on it.
Agree Col, Choose your go to oil, i also found most expensive worst, !st gear is just 1st gear, it clunks, lurches. Load of crap trying to fix it, just what they all do. Not even worth discussing. :confused1:
Barbastro, I try my arse out to understand your input, sometimes I get confused. Sometimes I get confused in normal life so don't concern🏅
wrong thinking organ......translator dixit :hat:
Quote from: grog on Tuesday, 15 September 2026, 07:30 PMBarbastro, I try my arse out to understand your input, sometimes I get confused. Sometimes I get confused in normal life so don't concern🏅
Yeah, a bit hard to decipher for sure. My take on what he's saying is if it had a drain circuit built into the cooler lines, you would be able to get more of the oil out. Then goes on to explain (ex a French manual) the oiling system circuitry. He does this using Google Translator, and presumably, reads everything here using the translator as well, and it would appear how some words are written in Spanish don't come out too well when literally converted to English. Case in point: " to the radiator or to 6
in yectors at head and " I reckon it means Injectors here.
On a similar topic, and one I found interesting.
Gen-3 Hayabusa.
The AU and US service schedules are listed in the handbook side by side.
Both countries have vaguely similar weather, distances, temps etc.
The AU recommended service intervals are 12,000K's, double those for the US, and AU then gets a longer factory warranty. Suzuki are happy to leave the oil in on a sporty bike for 12,000K's and guarantee it.
It's been discussed a few times but no one has ever found a solid proven reason why.
Could be because a lot of sport bikes get ridden harder, rev higher and get hotter, thus heating the oil enough to get rid of any water or petrol. :confused1:
Quote from: KiwiCol on Wednesday, 16 September 2026, 05:02 AMQuote from: grog on Tuesday, 15 September 2026, 07:30 PMBarbastro, I try my arse out to understand your input, sometimes I get confused. Sometimes I get confused in normal life so don't concern🏅
Yeah, a bit hard to decipher for sure. My take on what he's saying is if it had a drain circuit built into the cooler lines, you would be able to get more of the oil out. Then goes on to explain (ex a French manual) the oiling system circuitry. He does this using Google Translator, and presumably, reads everything here using the translator as well, and it would appear how some words are written in Spanish don't come out too well when literally converted to English. Case in point: Quote from: KiwiCol on Wednesday, 16 September 2026, 05:02 AMQuote from: grog on Tuesday, 15 September 2026, 07:30 PMBarbastro, I try my arse out to understand your input, sometimes I get confused. Sometimes I get confused in normal life so don't concern🏅
Yeah, a bit hard to decipher for sure. My take on what he's saying is if it had a drain circuit built into the cooler lines, you would be able to get more of the oil out. Then goes on to explain (ex a French manual) the oiling system circuitry. He does this using Google Translator, and presumably, reads everything here using the translator as well, and it would appear how some words are written in Spanish don't come out too well when literally converted to English.
that's how it is.
certain you
Could be that water cooled bikes run at a more constant temp so reduce oil breakdown and contamination from piston blow by?
I've noticed generally air cooled stuff does have shorter oil change intervals.
I was just wondering why a bike in the US and an identical one in AU, doing the same distances, the same weather, the same temps, absolutely no major difference in their build or use...
One has double the service intervals of the other, and the one with the longer service intervals gets a longer factory warranty.
:confused1:
Quote from: Tony Nitrous on Thursday, 17 September 2026, 04:45 PMI was just wondering why a bike in the US and an identical one in AU, doing the same distances, the same weather, the same temps, absolutely no major difference in their build or use...
One has double the service intervals of the other, and the one with the longer service intervals gets a longer factory warranty.
:confused1:
Aye that makes no sense to me either, the only difference I'd expect is possibly the grade of oil depending on ambient temps for different markets. Mind you I have heard of it before with other vehicles.
Whoa! A bit of a war broke out there. But maybe that's a good thing. I decided to try something different, though: pre-loading the gear lever while simultaneously easing off the throttle and pulling in the clutch during acceleration. For downshifting, I do the same thing, only I add throttle instead of easing off. And let me tell you, it's amazing—all the issues are gone. Somehow, other motorcycles weren't as sensitive to poor shifting technique. Now it's great. :)
Glad you've adapted to the GSX mate. Wishing you many years and time riding your bike.