RiderForums.com - Kawasaki Motorcycle Forum banner

1 - 20 of 27 Posts

·
Registered
Joined
·
972 Posts
Either the engine is running lean on the idle circuit, or your fuel system is failing (clogged vent tube in the gas cap or a failing fuel pump).

Have you done any engine mods?
 

·
Registered
Joined
·
39 Posts
man, i just noticed that particular problem w/ my meanie. only upgrade i got is BUB chambermaids, and it only happens when it's hot. think that's a lean issue? been looking for a good excuse to buy a PC or something similar, and if yer gonna do that might as well put a new intake on, right?
 

·
Registered
Joined
·
2,139 Posts
Sounds like a good enough excuse to me. That coupled with the fact that it's a shaft drive bike makes it even that much more noticeable.
 

·
Registered
Joined
·
31 Posts
Discussion Starter #5
Power Surging around 1500/2000 RPM any Gear

This surging thing is driving me nuts! Local shop says if no diagnosic code he don't know. Guess I will rig a tee up to check fuel pressure. Not experienced enough yet with the Fuel Injection System. I rode a Vulcan Classic this weekend and it did't have that problem. Somebody with Kawasaki has got to know something about this. Once above 2000 not noticable, seems only at 1500/2000. Feels like it is starving out of gas and then comming back. I have run a can of sea foam thru it and now running some Yamaha cleaner recommended by kawasaki dealer through it. I don't think the magic tonic is going to fix this one! Know any good books on Motorcycle Fuel Injection?
 

·
Registered
Joined
·
698 Posts
I would change the filter and drain the tank. May have picked up some moisture.
 

·
Registered
Joined
·
13 Posts
I had the same problem too! Surging at 1500/2000rpm... My issue began after i had the tank powder coated. There was some overspray in the tank and I was too anxious to ride to bother cleaning it out... within a week i started noticing the symptoms. I also tried fuel injector cleaner to no avail.



The problem obviously is fuel delivery related, and seems to be a lean condition so as a quick fix before a ride the other day I added a resister inline to the temp sensor to richen up the mixture, however, this only slightly improved things. It is definitely better now, but still not perfect. Did the original poster ever solve his problem? Please post if so! I think my next step is what i should have done in the first place... take off that tank and clean clean clean and possible put in a new fuel pump (it looks like the filter is integral to the pump, but fortunately the pump can be purchased at advanced auto for less than $150 (it's the same pump as the one on the '89 Mitsubishi Galant).

I will post back when i've got the new pump installed... keeping fingers crossed.
 

·
Registered
Joined
·
376 Posts
I notice mind has a very twitchy throttle responce around the 2k mark. If I am off the throttle rolling up to a light in second gear then try to get back on the throttle without using the clutch the thing starts bucking like an idiot.
 

·
Banned
Joined
·
269 Posts
I notice mind has a very twitchy throttle responce around the 2k mark. If I am off the throttle rolling up to a light in second gear then try to get back on the throttle without using the clutch the thing starts bucking like an idiot.
Sounds like a PCIII map issue. Lean most likely. Try running along at 2,000 rpm ~45 mph in 5th gear. Is it smooth or staggery?

What map are you running?
 

·
Registered
Joined
·
474 Posts
Mine does this too. All stock except for the V&H Longshots pipes. No fuel controller or any other changes (yet).
 

·
Registered
Joined
·
13 Posts
Ok, so I worked on the fuel system today...

First I took off the tank and tried to clean it. there was some slight sediment, but nothing much to speak of so i moved on to the fuel pump assembly. I disassembled it, cleaned the fuel strainer with a dip in some carb cleaner, and replaced the fuel filter with a generic one from advanced auto. I put the bike back together and took it for a test drive... still surging/stumbling at around 2000rpm. I then changed the coolant and gear oil just for fun and went back to advance auto to buy a new fuel pump. For anyone else interested the pump itself is a mitsubishi uc-t30... it is a common pump, used in a lot of other bikes and cars including the '99 mazda miata. I got an aftermarket pump from advance auto (airtex brand, p/n E2111). After I got it all done and put back together... same problem! Plus, i don't think the new pump sounds as good as the old one!

Back to the drawing board...
 

·
Registered
Joined
·
13 Posts
Ran some seafoam through the intake... seems to have made a little bit of a difference. I'll try another can after work. My latest thoughts...

The stock air filter was left unchanged and eventually fell apart. some foam crap got sucked into the throttle body. I'm not sure if it made its way all the way into the combustion chamber but it seems likely and this may have caused some crap to build up inside the cylinders. Not a good situation. I'm not sure why this would affect me at 1500/2000rpm though??

Has anyone else resolved this issue? My bike runs alright. especially under throttle or high rpms it really runs great. but it is annoying to have this surging at 1500/2000rpm especially since 2000 is where i used to like to cruise. One more note... the surging seems to only occur when 'cruising' at 2000rpms --> when under heavy acceleration/throttle, the 1500/2000rpm range is fine, but at a steady state or deceleration, it starts to buck.


If anyone has any experience please chip in!
 

·
Registered
Joined
·
474 Posts
Mine does this too. All stock except for the V&H Longshots pipes. No fuel controller or any other changes (yet).
Just a follow-up, now that I have a PCIII installed (and a Chuckster Intake), it no longer surges around 2000 rpm. I'd say it's the new fuel mapping that got rid of the surging.
 

·
Registered
Joined
·
474 Posts
Your mapping richened up the lean condition that usually causes the surging. Which map did you install?
Yep. I installed the 019 map by accident. Meant to install the Thunder map and later realized I did the 019. I was comparing the 2 maps using the comparison tool and got myself crossed-up. Thunder map is next.
 

·
Banned
Joined
·
269 Posts
When you hook your laptop up next also make sure your throttle position is calibrated so the PCIII shows zero % with the throttle closed and the bike running (idling). This is IMPORTANT if you want good small throttle opening mapping. !00% at full throttle should be close but is less critical. Running along at 2,000 rpm in 5th (~45 mph indicated) is only 2% throttle opening with good mapping. 65 mph cruise is only 7-8% open. Being off a little can be alot.
 

·
Registered
Joined
·
474 Posts
When you hook your laptop up next also make sure your throttle position is calibrated so the PCIII shows zero % with the throttle closed and the bike running (idling). This is IMPORTANT if you want good small throttle opening mapping. !00% at full throttle should be close but is less critical. Running along at 2,000 rpm in 5th (~45 mph indicated) is only 2% throttle opening with good mapping. 65 mph cruise is only 7-8% open. Being off a little can be alot.
Understood. I checked it this morning and the PC was reading 2% with the throttle fully closed. I reset the closed throttle setting and left the full throttle setting as-is.

I see what you mean : a little can be alot - especially when we're looking at such small throttle opening at very common riding conditions.
 
1 - 20 of 27 Posts
About this Discussion
26 Replies
16 Participants
jwarden
RiderForums.com - Kawasaki Motorcycle Forum
Rider forum is a community for motorcyclists including both street and track riders. Come in and talk about your favorite model.
Full Forum Listing
Top