Rough running, low revs

[Phill P]

Hi all

Now this has been spoken of before but I just wanted to get the correct info.
I've had the bike 3 plus years, always starts fine runs fine, exhaust tips have always been very sooty, when I changed the plugs two were sooty and the other two ok although two seemed quote loose. Went out yesterday and got stuck in some shocking traffic jams, bike was lumpy under 2500 revs, always has been but I generally avoid traffic jams. Had a look up here and throttle cable was mentioned, took a look at mine and has no slack at all. Had a go at listening to the cold map change when increasing revs in 1st gear.....no increase in revs engine warm, could the oil temp switch be fubar hence lumpy running low revs and sooty tips.

Ps I'm not very good with a multimeter 

Thoughts please, cheers Paul

[Blubber]

Lumpy ( as in on/ off) at low speed usually is the throttle position sensor

Sooty van be a very dirty air cleaner or a power commander going bad.

Hard to experience behind a keyboard vs what you experience on a bike but i would start with the basics if this was happening to my bike

Throttle cable play
Tps and stps
Synchronise the tbs
Check the fuel pump + filter and the fuel pressure regulator

Takes out a lot guessing

Hth

[Phill P]

Lumpy ( as in on/ off) at low speed usually is the throttle position sensor

Sooty van be a very dirty air cleaner or a power commander going bad.

Hard to experience behind a keyboard vs what you experience on a bike but i would start with the basics if this was happening to my bike

Throttle cable play
Tps and stps
Synchronise the tbs
Check the fuel pump + filter and the fuel pressure regulator

Takes out a lot guessing

Hth

Cheers for the thoughts, can confirm air cleaner is new as are plugs.

I'll get a friend who understands a multi meter on the case.

Cheers

Paul

Paul

[Hooli]

Is it drinking fuel? Mine was down to about 28mpg when the oil temp sensor went.

If you do test it, it's a two wire connector under the RH side cover. White/black and black from memory. The figures are in the workshop manual, as I recall it's about 100KOhm at 0c and mine was around 1000KOhm. Can you tell I found the issue in winter?

[Globalrider]

Tea Bag!

[Phill P]

Tea Bag!

It's certainly something to check although apart from seeming very rich and rough lower down it runs fine

[Phill P]

Is it drinking fuel? Mine was down to about 28mpg when the oil temp sensor went.

If you do test it, it's a two wire connector under the RH side cover. White/black and black from memory. The figures are in the workshop manual, as I recall it's about 100KOhm at 0c and mine was around 1000KOhm. Can you tell I found the issue in winter?

Tbh I've never really checked the mpg but if you stand behind it it smells like a 1973 range rover V8, unsure if that's normal on a gsx, don't recall it on my carbed xjr1300. It definitely didn't do the rev increase in 1st. When cold starting the revs are higher, then it drops to around 1100 then finally ticksover at 900 so after reading through here I may increase to 1100 .
Pairs block of done and running Healtech tre.
Fowlers had a sensor at £220

Paul

[KiwiCol]

I personally wouldn't be getting a new sensor until I could prove the original a dud.  If she's running rich  we need to find the reason, especially as it appears to be just 2 cyl?

The 'proper' idle revs are 1100 on a warmed up engine. Start up should go into fast idle, 2200 - 2500 sorta thing then ease back fairly quickly to 1100.  This is temperature dependant though, so the colder it is where you are the longer it'll take to drop back to 1100.  Some owners have found they prefer tick over at 1200, up to you.   
Now to see if you're stuck on the start map, once the bike is at normal operating temp and it's normal tick over, pull the clutch in & drop it in to 1st, don't give any throttle input and gently begin releasing the clutch, watch the rpm dial and listen, it should slightly increase revs as the clutch is let out. Maybe 100 - 200 revs, but it's noticeable and should be there. If it does not do this, you're running on the start map continuously, which is richer than normal riding. This would account for rich smell.  Have a crack n see if she's doing everything right.

[Hooli]

Is it drinking fuel? Mine was down to about 28mpg when the oil temp sensor went.

If you do test it, it's a two wire connector under the RH side cover. White/black and black from memory. The figures are in the workshop manual, as I recall it's about 100KOhm at 0c and mine was around 1000KOhm. Can you tell I found the issue in winter?

Tbh I've never really checked the mpg but if you stand behind it it smells like a 1973 range rover V8, unsure if that's normal on a gsx, don't recall it on my carbed xjr1300. It definitely didn't do the rev increase in 1st. When cold starting the revs are higher, then it drops to around 1100 then finally ticksover at 900 so after reading through here I may increase to 1100 .
Pairs block of done and running Healtech tre.
Fowlers had a sensor at £220

Paul

Nah they shouldn't stink of fuel, so it does sound rich.
Those sensors are about £70 from webike japan, just stick the part number from Fowlers into the webike search bar. But like I said, they are easy to check with a multimeter. Oddly enough the engine thinking it's really cold doesn't affect the fast idle times, they still drop to normal at the usual rate.

[grog]

Check that oil temp sensor. Idle speed up, mine would just cut out at 900.If no rev change with clutch movement, need a new clutch switch. A couple of places to start Mate.Good luck.

[Phill P]

Cheers everyone, defo no increase in revs with clutch out in 1st with warm engine and does smell rich and never smells any less rich. But will check the sensor and if that's OK I will get the tank off for the teabag filter 

In comparison the z1000sx you could literally inhale it without a problem, although too bloody quiet for my liking

Paul

[Hooli]

Aye clutch switch is a good call too, I forgot that one as we'd gone off on oil temp sensors.
A quick check there is start the bike, unplug the clutch switch and ride. If it behaves better you've found the issue.

[Phill P]

Check that oil temp sensor. Idle speed up, mine would just cut out at 900.If no rev change with clutch movement, need a new clutch switch. A couple of places to start Mate.Good luck.

Ah, wasn't aware of the clutch switch doing that, cheers will give it a try

 

Paul

[Phill P]

Aye clutch switch is a good call too, I forgot that one as we'd gone off on oil temp sensors.
A quick check there is start the bike, unplug the clutch switch and ride. If it behaves better you've found the issue.

I'm going to Rykas next week so will be a good chance to try it out.

Paul

[Eric GSX1400K3]

Another easy test of the oil temp sensor is to take it out, and re connect it to the plug. Connect the multimeter to the back of the plug (using the pointy probes) and with the setting on resistance, holding the sensor in your closed hand, you should see the ohms drop as the sensor warms up. If it  doesn't then its faulty.

Also good tip re the clutch switch, but dont disconnect before starting, as its interlocked to the starter relay.

3 sensors to check: oil temp, clutch and throttle.

Webike japan is cheapest for oem Suzuki parts.