still lumpy

[oilseal21]

So got my 05 busa had been lying up changed fuel made sure idle was ok (about 1200rpm?) runs like a dream once over about 3000rpm but below that and idleing its lumpy or jumpy whatever rocks your boat If im in traffic im riding clutch and trying to keep revs up to keep it smooth when i go to open it up I pull the throttle and it hesitates for a second then trys to throw me off the back of it when it hits its groove. It has twin scorpian cans and a k&n filter I dont think this warrents a power commander so any ideas whats causing it my head is wrecked hoping to do a bit of touring in april and would love to get this sorted........pleeeeease help me!!

:unhappy:

 

[Highliner]

You could try syncing up the throttle bodys to help smooth it out. I find that these bikes are naturally a touch on the rough side at idle however..

 

[oilseal21]

Thanks highlander will try that

 

[Tufbusa]

My Gen II busa does the very same thing. Increasing the idle speed will help but not eliminate the issue. A proper tuner combined with serious cash can totally eliminate that issue but it's spendy! As I understand it, the ECUnleashed can be used to smooth the throttle application at low RPM.

 

[SKnight]

Yeah the first gens aren't the smoothest idlers and can be a bit choppy especially holding RPM with the clutch pulled. It can be tuned out but if you keep the throttle bodies synched up and set the idle at 1300 or so it's much happier.

 

[oilseal21]

thanks lads new to busas so dont know alot about the tuning side but love everything else about it

 

[Tufbusa]

Yeah the first gens aren't the smoothest idlers and can be a bit choppy especially holding RPM with the clutch pulled. It can be tuned out but if you keep the throttle bodies synched up and set the idle at 1300 or so it's much happier.

Throttle bodies aren't the issue. The ECU is the issue.

Idle up from 1100 to 1300 will have little effect. The idle has to be increased enough to keep the injectors fueling when the throttle is completely closed. On the opposite end of the spectrum, we idle our race bikes up to 2500 rpm. 200 RPM will make little if any noticeable difference.

 

[SKnight]

Throttle bodies aren't the issue. The ECU is the issue.

Idle up from 1100 to 1300 will have little effect. The idle has to be increased enough to keep the injectors fueling when the throttle is completely closed. On the opposite end of the spectrum, we idle our race bikes up to 2500 rpm. 200 RPM will make little if any noticeable difference.

I don't think this is a race bike, my '06 model idled much smoother when the throttle bodies were clean, synched up and idling around 1300 or so, from the day I got it to the day it disappeared. A large part of smoothing out the idle is getting the engine just into a happier range where the cams profile cleans up some. 200RPM can make all the difference sometimes, otherwise why would the spec be 1050+-100 or whatever the first gen was.

It's electronic fuel injection, the injectors are spraying so long as they have fuel pressure and told to do so by the ECM, changing the idle has nothing to do with the injectors themselves, idling an engine at 2500RPM you're simply moving the engine idle speed into a range with better tuning. The injectors do as told by the ECM, if the ECM calls for .9ms on time at a specific RPM then they give it provided all is in order.

You don't know everything. You surely don't want to go here with me, not with my background. But go ahead and gather your cronies around for your chat session.

 

[SKnight]

Plus idling an engine that high serves to reduce pumping losses at closed throttle. In other words it reduces engine braking which makes cornering easier in the same way as a slipper clutch does.

 

[card16969]

check your throttle body sync, replace your plugs and check your connections on your coils

 

[dmallord]

hmmnnn...so you have slipons and a k&n. the stock ecu is setup for a stock intake/ exhaust. if it was me i would get a pc and then bring it to a tuner for an optimal map.

 

[karnage]

Mine runs smooth at idle.I had a good tune done with a custom map and set the idle at 1100.Check for vacuum leaks, maybe set the TPS.A PC3 can always be a good thing on these as the stock MAPS suck and can really use re-tuning from the factory.When I got rid of the pairing valves, put in a BMC filter and did the full airbox mod and now a Brocks, it runs really good.

 

[oilseal21]

Thanks men giving it to my mechanic at the weekend and see what he thinks thanks for all the help your a great bunch of men

 

[oilseal21]

right my mechanic synced throttle boddies check injectors and has come to the conclusion its a dodgy coil stick. Anyone heard of this being an issue on 05 busas? It has spent long periods of time lying up only 6700 miles in 7 years if that makes any difference

 

[dadofthree]

Replace all the coil packs then. These bikes have a nice little lope care of zuki. An ECU tune would make it as good as it gets with the right tuner. I seriously doubt it's an issue with that amount of miles on the clock but has he checked the valves ?

 

[oilseal21]

Had a look from top to bottom he allows there is a weakness in one of the coils in low revs and as the revs go up over about 5000 the spark is stronger makes sense and it runs fine up in the revs so I hope it's that

 

[oilseal21]

So it's not coils either but did find loose vacum pipe road test tomorrow to see will that help fingers crossed

 

[snowprophet1]

I had the same issue w/my '05 this week. I bought it in December, and never rode it until this week. Fresh gas and plugs weren't the answer and the compression was within 2psi across the board. The thing ran good after 2,500-3,000, but pulling out of an intersection made me look like a rookie! I checked my tps setting and it was out just a smidge. I set it correctly and it is as smooth as warm butter on toast! Start your warmed up bike, put in the jumper when idling at 1,150rpms, and see which of the three lines you're on at the clock display. The display will read C00, and a line to the left. If the line is centered, you are set correctly. If the line on the left is to the top or bottom of the digits, you need to tweek your tps a little, and you should be good. Just rode my 'busa for the first time this week and love it!

 

[oilseal21]

Thanks snowprophet will try that one hopefully will work out well

 

[Tufbusa]

I don't think this is a race bike, my '06 model idled much smoother when the throttle bodies were clean, synched up and idling around 1300 or so, from the day I got it to the day it disappeared. A large part of smoothing out the idle is getting the engine just into a happier range where the cams profile cleans up some. 200RPM can make all the difference sometimes, otherwise why would the spec be 1050+-100 or whatever the first gen was.

It's electronic fuel injection, the injectors are spraying so long as they have fuel pressure and told to do so by the ECM, changing the idle has nothing to do with the injectors themselves, idling an engine at 2500RPM you're simply moving the engine idle speed into a range with better tuning. The injectors do as told by the ECM, if the ECM calls for .9ms on time at a specific RPM then they give it provided all is in order.

You don't know everything. You surely don't want to go here with me, not with my background. But go ahead and gather your cronies around for your chat session.

Obviously you have no clue! However, you are honest by beginning your post with "I don't think"!