Jerking at low revs

[Jambo]

HI all.

Last summer I posted a rant about the service done to my 14. Long story cut really sort, bike went for fine tunning and came back jerking at low revs. The shop decided to install a 16 front sprocket to "fix" the problem, it didn't. So here is what I did.

I changed the chain which was rusty and old.

Tunned carbs with CarbtunePro, which was a lot of fun!

And still the bike was jerking while coasting from 2000rpm down to 1500rpm which is very annoying.

Reading the manual, I noticed that the plugs did not match with the ones on the receipt ngk CR8E. But actually the plugs installed were denso u24 esr-n, which are the same as CR8E, not the right plug.

So I ordered some 4 Denso U24ETR

Bike does not jerk violently anymore.

There is still room for improvement with the carbtunepro I guess.

I have now reinstalled the propper front sprocket 18. 16 is a lot of fun actually, and is ideal for urban use, but on the motorway does not work so well. It still goes like hell.

Damn mechanics...I only trust myself from now on.

Cheers

[KiwiCol]

Hmmmm, changing the rusty old chain would have been first on the list at the shop I'd of thought, not putting a 16T front on it!    I dunno about those plugs, I'd stick with the factory recommended ones myself.  You're just balancing the throttle bodies (I hope) with the  CarbtunePro, not adjusting the linkages & connections.   A multimeter on the TPS to check it's adjusted correctly too.

Once you have new plugs, new sprockets & chain, balanced T/B's and good fuel, they're pretty much sorted as a rule.   

[seth]

I agree with @KiwiCol
Knackered chain ECT would be first thing to go.
16 front is check the front if the swingarm as it'll have been rubbing the big rubber buffer away and may be even gone through it.
If your having problems I'd fit standard plugs like everyone else so you know it's not being different causing your problems .
As says @KiwiCol check the to's and stps .
Before you balance the throttle bodies.
Think @Andre Did a write up on how to do them.
Good luck

[grog]

There is a process to make 14 super nice. Of course new chain n sprockets. Adjust those throttle butterflys, great step. Next is get idle correct, 1100. Get your TPS down to 1100 also. Adjust throttle cables at bars, tight as you can without making a diff when turning bars lock to lock. Get rid of PAIRS or block off. Clean air filter and fuel filter essential. My next, final step, some agree , some dont. Take off negative batt lead, touch it to positive terminal for at least 30 seconds. Should now run like the best youve ridden. So smooth. Youll need to reset clock. Not sure ive missed anything, slap me if i have. Thats my process about every year or so. Best running/smooth bike ive ever owned. It wasnt when first bought,Suzuki serviced.

[steve porter]

There is a process to make 14 super nice. Of course new chain n sprockets. Adjust those throttle butterflys, great step. Next is get idle correct, 1100. Get your TPS down to 1100 also. Adjust throttle cables at bars, tight as you can without making a diff when turning bars lock to lock. Get rid of PAIRS or block off. Clean air filter and fuel filter essential. My next, final step, some agree , some dont. Take off negative batt lead, touch it to positive terminal for at least 30 seconds. Should now run like the best youve ridden. So smooth. Youll need to reset clock. Not sure ive missed anything, slap me if i have. Thats my process about every year or so. Best running/smooth bike ive ever owned. It wasnt when first bought,Suzuki serviced.

While leaving positive connected to battery?

[grog]

Yes Steve. On later cars we call it a CAN BUS reset, drains all power from system, just a reload, capacitors etc sometimes just need their arse kicked. 

[steve porter]

Yes Steve. On later cars we call it a CAN BUS reset, drains all power from system, just a reload, capacitors etc sometimes just need their arse kicked.

Interesting, not something I would have attempted without someone trying it first for fear of blowing something up,thanks for the info, I take it that this is a turbocharged version of unplugging everything for a week or so to reset everything that my brother did to his VL turbo on advice from someone, which did the job by the way

[KiwiCol]

Yep Steve, same thing, just faster.   (obviously a B/W method . . . )

[Eric GSX1400K3]

[/quote]
While leaving positive connected to battery?
[/quote]

Surely not? Disconnect both THEN touch the leads together is what I  would have thought?

[KiwiCol]

You've disconnected the neg lead, there's no power flowing anywhere, you're just draining the capacitors & re-setting the ECU.  Or just leave it disconnected for a couple of days, that drains everything too.

[grog]

Correct Col. No circuit once negative removed. Doesnt matter if positive removed or not. Done it a hundred times.

[Jambo]

There is a process to make 14 super nice. Of course new chain n sprockets. Adjust those throttle butterflys, great step. Next is get idle correct, 1100. Get your TPS down to 1100 also. Adjust throttle cables at bars, tight as you can without making a diff when turning bars lock to lock. Get rid of PAIRS or block off. Clean air filter and fuel filter essential. My next, final step, some agree , some dont. Take off negative batt lead, touch it to positive terminal for at least 30 seconds. Should now run like the best youve ridden. So smooth. Youll need to reset clock. Not sure ive missed anything, slap me if i have. Thats my process about every year or so. Best running/smooth bike ive ever owned. It wasnt when first bought,Suzuki serviced.

Lets see Grog.
Chain and sprckets done.
TB adjusted done.
Idle 1100 done.
TP down to 1100 NOT done. I know what it is, I can identify it on the bike, but can't find the procedure on the haynes manual. On other more recent suzuki models, I've seen people on youtube do it. They jump the diagnose connector with a piece of wire to get it in to dealer mode. I wounder how it works on the 14?
Throttle cables adjusted done
Get rid of PAIRS or block off NOT done. And there is another interresting subject to explore. Before the bike went to the shop it used to pop while coasting, which is the result and purpose of the PAIRS thing, burn any fuel on the exhaust gasses right. I doesn't pop any more, I am confused. The shop didn't remove them, but might have blocked them. I liked the pop, it wasn't excessive, just here and there. But taking it all out, in my opinion, cleans the upper engine area, which is stuffed with hoses.
The fuel filter is the teabag inside the tank? not done. Do I have to go in the fuel tank...shiiiiiiiit, I don't feel confidant for that yet, but I will study it on the manual and probably will find out it's not a big deal.
Air filter K&N should have been cleaned last june, but we have established that the mechanic was not thorough, this one is a maybe.
Never has it crossed my mind to drain electronics. I've done it dozens of times on my PC back in the day.

I agree with @KiwiCol
Knackered chain ECT would be first thing to go.
16 front is check the front if the swingarm as it'll have been rubbing the big rubber buffer away and may be even gone through it.
If your having problems I'd fit standard plugs like everyone else so you know it's not being different causing your problems .
As says @KiwiCol check the to's and stps .
Before you balance the throttle bodies.
Think @Andre Did a write up on how to do them.
Good luck

Seth, 16 is gone. The rubber buffer had some damage. Still fine. I know this because swing arm come of for thorough cleaning and bearings inspection, which looked good.
Standard plugs installed
TO is tip over and stps is secondary tps? you guys are killing me here. I am still trying to figure how to adjust TPS and now TO and stps.

With standard denso U24ETR bike runs much smoother, but still isn't perfect. And that's not good enough for me.

So next will be adjusting TPS, STPS, TO.

Cheers guys

[Hooli]

You adjust the TPS by unplugging it & putting a mulitmeter across the wires, all the details are here.

https://gsx1400owners.org/forum/index.php?topic=263.0

Have a look through the stickies in the technical sections & you'll find most of your questions have already answered over the years.

If you haven't got it, you can download the factory workshop manual from the downloads section too.

[grog]

Jambo, get TPS adjusted. See how it is. rest can wait. Balanced throttles, 1100 revs, 1100 at TPS, should be smooth as. Just ride it. 

[grog]

I forgot, after draining system, battery wires crossed. Can remember you need to open/close throttle twice. That was instructions from Andre, very clever person. Havent heard from him lately. Loved your info Mate.