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ZXR400H losing power when going uphill

Posted: Fri Jan 07, 2011 7:21 am
by ZXR400RXZ
Hi there

I recently bought a ZXR400H1 model had it serviced not too long ago.
they changed the oil, oil filter, spark plugs etc, not sure if the replaced the fuel and air filters though, lost the job sheet.

recently i noticed that the bikes uphill power kept deteriorating, first it was fine going uphill with a pillion.
eventually after a while it started to struggle going uphill with a pillion, but went fine when i rode alone, and now recently it started struggling uphill without any pillion passenger.

I'm not sure if its dirty carbs or timing thats out, someone mentioned to me that it might be the chain and sprocket, as I am new to this i do not know much about bikes, but do have a mechanincal background.

can anyone please assist?

Regards

Re: ZXR400H losing power when going uphill

Posted: Fri Jan 07, 2011 12:27 pm
by bendog66
..........................did you try changing down a gear? confuddled

Re: ZXR400H losing power when going uphill

Posted: Fri Jan 07, 2011 5:58 pm
by Daniel.p
make sure you have little slack on your chain try pulling your wheel back and a notch or two might solve your problem

Re: ZXR400H losing power when going uphill

Posted: Sat Jan 08, 2011 4:39 am
by ZXR400RXZ
bendog66 wrote:..........................did you try changing down a gear? confuddled
Well basically it was when going up a ramp to a second level parking, was going up in first gear but bike really struggled, noticed though that it only happens when its really hot

Re: ZXR400H losing power when going uphill

Posted: Sat Jan 08, 2011 4:41 am
by ZXR400RXZ
Daniel.p wrote:make sure you have little slack on your chain try pulling your wheel back and a notch or two might solve your problem
I think there is a little play on the chain will give it a try and post feedback, thanks :smt002

Re: ZXR400H losing power when going uphill

Posted: Thu Jan 13, 2011 1:22 am
by ZXR400RXZ
Daniel.p wrote:make sure you have little slack on your chain try pulling your wheel back and a notch or two might solve your problem
Ok I adjusted the rear wheel to increase the tension on the chain, my chain was way loose.
I read somewhere that it needs to be set so that it moves about 1/4 inch at its loosest point, so i did this.
When testing the bike I felt an immediate change in performance, its more responsive and shifts gears better, it went up the ramp with ease when I was alone, have yet to try with a pillion.
thanks for the help

Re: ZXR400H losing power when going uphill

Posted: Thu Jan 13, 2011 8:55 am
by cargo
So there you go folks all those years of trying to get more power from your ZXR and all you needed to do was tighten your chain until it was like a bow string and you'd have been there.............................awesome stuff guys thank you.





NOTE

This post contains extreme scarcasism................................. do not be offended

Re: ZXR400H losing power when going uphill

Posted: Thu Jan 13, 2011 7:22 pm
by extonyg
haha to the above comment.....im not sure what the manual actually says about chain tightness but 1/4 inch is way tighter than i would personally have it. having it that tight doesnt leave any give for suspension movement on take up and bumps etc, and especially carrying a pillion. i would loosen it off a bit otherwise it could cause excessive wear or the chain or worse...

Re: ZXR400H losing power when going uphill

Posted: Thu Jan 13, 2011 7:42 pm
by cargo
I reckon that at 1/4 inch the output shaft bearing is under serious pressure once some weght is on the bike never mind what will happen on a bump in the road.
The sprocket carrier bearing will also be less than happy and if the chain snaps could do all sorts of fun things on it's way out...........including leaving a nice chain shaped bruise on a leg.................................

Re: ZXR400H losing power when going uphill

Posted: Tue Jan 18, 2011 11:17 pm
by gavinfdavies
i've read something similar i think. I recall the manual says 10-15mm when on the side stand. This is less than i'd usually set, but then again there is already i'd gues about 50% of the working weight on the wheel already (the rest being me). That said surely setting slack on a paddock stand would have the same effect since the stand rests on the swingarm?

but yeah, 1/4 inch seems way tight - but you it slackened itself of alot within about 5 miles or 3 speed bumps, whichever came soonest!

Re: ZXR400H losing power when going uphill

Posted: Tue Jan 18, 2011 11:20 pm
by gavinfdavies
if it's getting worse in the same situation (ie same hill, first heavily loaded, then medium load etc) could it be more to do with the engine load? ie wider throttle openings as the revs drop as the bike slows. If the fuellings off a bit, this could be making it bog (going too rich?)