No power at top end on GSXR

[Guest]

Hello all,

I desperate for help with a problem on my GSXR600. I took it to the garage last week as it was stalling in neutral/1st gear. The mechanic cleaned the air filter/box, replaced spark plugs and changed the oil which fixed the problem but when I got on the motorway to give it a blast, there was no power around 7000 revs in 4th/5th/6th gear! It felt like a restricted bike. It feels fine through 1st/2nd/3rd gear and accelerates with no problem but when I'm cruising in 5th/6th and move to overtake, it flatly refuses to go any faster and the revs won't move above 7000. In fact, if it’s at 100 and I give it an extra burst of juice I feel it slow slightly then speed back up again, the revs neither dipping or screaming, just like something is holding it back.

It will, given time and a sufficiently straight bit of road, creep slowly faster, but it used to nip up over the ton for the overtake with ease for a bike of its age. At first I thought the clutch might be slipping, due to the sensation of loss of power followed by it reappearing, but it’ll still do very hard acceleration in 1st through 3rd without any loss of power or sign of slip. I only really notice it at about 7.5 to 8k revs in 5th or 6th gears. Also, the revs are fine in early gears and will zip right round the clock if I were to let them.

The mechanic at the garage can't fathom it out and he said that it can't be anything he's done as he only changed the plugs and oil - he's a reliable guy but he really thinks the problem was there all along.

Any help would be most appreciated!!!!!!

[rennie]

i really don't know! could be allsorts, has he partially blocked the air filter? has it got pipe/can? wrong plugs? wrong filter?try it with filter off altogether, not for long. sure somebody will have more idea, say hello in newbie section

[Guest]

you say the air filter been cleaned / replaced

Reckon that could be the problem - If one of the breather pics not been correctly fitted back then this is dramatically gonna reduce the air/fuel mixture compromising the full capacity of the carbs. If there aint enough air getting through then the bike is gonna run like a bag o shyte.

it does sound like the probles lies withing the air filter / carbs.

take bike back to garage.. ask him to double check all breather pipes.

if your mechanicaly minded urself.. whip the carbls off and give them a flush out too... bits of crap from airfilter may have fallen into them on removal and be restricting some of the needles/jets

alternativelty...

when plugs have been replaced were the plug caps loose or corroded.. even attached back correctly.. the bike may not be running on all cylinders which again would reduce the overal performance of the bike.

any probs.. gis a shout

Stew.

[Voodoo]

Years ago I used to have a 600 and the symptoms were very similar to what you've described. Upto 6000 revs it seemed perfectly okay, but over that it just wasn't right. I tried allsorts and nothing seemed to fix it. In the end after months of messing with it I decided to sell it. My mate who owns a bike shop sold it for me but before he did it was sat around in his showroom for a while. A customer came and took a test ride on it and whilst this happened the fuel pump failed. My theory is, the fuel pump was on its way out, with a small amount of fuel needed, the bike ran fine, but when it needed a large amount of fuel (i.e. higher gears) then it just couldn't cope.

Just incase your not aware, 6000 revs in top gear uses a lot more fuel than 6000 revs in first gear.

[Guest]

Not sure about the bike you have to be honest. I did have a similar outing on my old Thunderace thou. Does your bike have a powervalve?? If so, check to make sure the cable was not disconnected.....

[fuzzrr]

Also you didn't say what year the bike is and whether it is injected. Could it be that the ecu has picked up a fault somewhere else and has gone into 'safe' mode.

You may need to get a dealer to plug it in the pooter and check it out.

[Guest]

Was the bike standing any length of time, as had a prob with mine cutting out, took it 2 shop and they deglazed the carbs, no further prob's since.

[Guest]

Also you didn't say what year the bike is and whether it is injected. Could it be that the ecu has picked up a fault somewhere else and has gone into 'safe' mode.

You may need to get a dealer to plug it in the pooter and check it out.

 

It's an 'R' plate - 1998. The garage I bought it from said it used to have a dynojet(?) fitted and when I first bought it, the engine was cutting out in low gears - he said it was just 'running a bit rich'(?) and he fixed it. I've had no problems for the past 2 years until this. Not sure if this is what you mean by injected? (sorry I'm not very mechanically minded and don't know what a 'pooter' is!!)

[Guest]

Was the bike standing any length of time, as had a prob with mine cutting out, took it 2 shop and they deglazed the carbs, no further prob's since.

 

The bike hasn't been left standing - I use it most days.

[Guest]

Also you didn't say what year the bike is and whether it is injected. Could it be that the ecu has picked up a fault somewhere else and has gone into 'safe' mode.

You may need to get a dealer to plug it in the pooter and check it out.

 

It's an 'R' plate - 1998. The garage I bought it from said it used to have a dynojet(?) fitted and when I first bought it, the engine was cutting out in low gears - he said it was just 'running a bit rich'(?) and he fixed it. I've had no problems for the past 2 years until this. Not sure if this is what you mean by injected? (sorry I'm not very mechanically minded and don't know what a 'pooter' is!!)

 

Injected, fuel injected, not carburretted.

pooter, computer. If its an ecu fault shop will plug laptop into the bike to 'see' any faults.

[Stu]

it will be a carbed bike not injected

could be a breather split or not connected also could be fuel pump

when you switch the ignition on does the fuel pump prime up (do you hear a whine from the tank) if so how long does it prime for ? 2 or 3 seconds or longer ?

[Guest]

it will be a carbed bike not injected

could be a breather split or not connected also could be fuel pump

when you switch the ignition on does the fuel pump prime up (do you hear a whine from the tank) if so how long does it prime for ? 2 or 3 seconds or longer ?

 

Yeah - the fuel pump does prime up for about 4 seconds (or it used to - it's been at the bike shop for nearly a week!) I'm picking it up tonight so I'll listen out for it. If it doesn't 'whine' or whines too long, I'll ask him to check the fuel pump again (he said he has checked this and the fuel is flowing fine!) Thanks for your advice.

x

[fuzzrr]

What's the lateset Scoobs?? Did you get any joy when you picked it up?

[Guest]

It's back!!!

Thanks to you all for your advice - I picked the bike up on Friday and it's back to it's best! The mechanic said he simply took everything out again, air box/filter/spark plugs (put another set of new ones) and tested the fuel pump and he couldn't see anything wrong. Went for a blast up to newcastle to see the boyfriend and it was sweet!!!

Thanks again everyone - I have a smile back on my face!!!

x

[Guest]

nice1,

[fuzzrr]

Result then!!! Thank f*** for that eh??

[Voodoo]

Why don't you ever see white dog poo on the pavements anymore?????

 

Because they've changed some of the ingredients of the the dog food!

[fuzzrr]

Well I want to start a lobby to bring back white dog poo!!!! It was far nicer to tread in than the brown gungy stuff you have nowadays!

Back when I was a lad you didn't really care if you stood in a whitey cause it would just fall off!!! But now,,,,,,,oh no, it's like a bloody explosion has gone off on the bottom of ya foot.......

BRING BACK WHITE DOG POO!!!!!!!!