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Discussion Starter #1
I bought a 2010 RC8 a few months ago. When it gets hot outside (24 degrees C/ 75F) and the engine is fully warmed up the bike will not rev past around 7000 RPM it just bogs out. You then go to the next gear and it will accelerate again to 7000ish and bog out. I live in Calgary so our summer weather is gone and the dealer has been unable to diagnose the problem. I took it to the track last week (cool temps 12 degrees C) and it comes out of the corners hard but on the straight although it does not stop at 7000 the upper 8500 plus RPM power is fluffy not really wanting to pull red line. Anybody else experienced anything like this? On a positive note the handling on track was fantastic.
 

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sounds like petrol starvation, fuel line not connected properly or fuel pump faulty. have you let the bike run low on fuel?
 

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I am convinced that this is a starvation problem caused by either a faulty pump or a clogged fuel strainer inside the fuel pump. Maybe reading this thread - where one of the guys says that this is a typical RC8 problem - will help you to solve the problem.
http://www.ktmforum.co.uk/supermoto/58622-990-sm-problem-pls-help.html

Good luck!

Cheers, Steve
 

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Thats sounding like the fuel starvation problem I had, the fuel filter collapses around the fuel pump and doesn't let enough fuel through. Will it rev past 7k when its static? mine would but when it was moving it just refused to go over 7k.
 

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just had a problem with fuel starvation at hgh rpm on my track bike , although would rev out fine for first couple of laps then losing power after that.
fuel filter on pump , inside tank was very dirty / clogged. ran ok after pump was dismantled to clean filter. 08 bike , new this year with less than 1000 miles on.
 

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Teamfly, aftermarket paint job or all as it came from the factory?
 

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factory fresh ( apart from sitting for 2 years ! ) , initially thought kinked breather but removing it didnt cure fault. luckily a friend who is very experienced bike mechanic helped out , i would have said filter looked ok until he began cleaning it - went from looking like a teabag to being white.
inside tank also pretty coated , almost mouldy looking.?? ran perfectly after filter & tank cleaned.
 

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That's a poor state then!
 

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aye , at a loss to think why , i imagine the bike would not have sat with any fuel in it from 08 untill this year when it was registered.
wouldnt have thought a fill of dirty fuel would have coated the tank , + my jerry cans filler jug are clean.
delighted to have it fixed though.
 

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Discussion Starter #11
Thanks for all the replies and comments. Not too many RC8’s over here so this site is pretty handy. The bike does rev past the 7000 mark when static but under load it’s a problem. Also the first time I noticed the problem was while running with the low fuel warning flashing. That being said based on all the posts it seems like the filters are the place for me to start. This should be the dealer’s problem as I have less then 1000 miles on it but its likely easier to just take a look myself. I’ll let you know how I make out.
 

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they will rev to maximum standing still, when the bike is in gear and moving with a rider on it will need more fuel. the fuel filter will have sucked itself together. it just needs taking out and pulling apart. havent done it myself, but a few have and i think it is a pretty easy job to do yourself.
 

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Discussion Starter #13
Got the pump out of the tank but I'm unsure how to get the actual filter out of the pump housing. I'm going to drop a post in the guys thread that did the removal himself and ask for a few pointers.
 

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Hi,

I am the guy who posted the link to to the other thread in the Supermoto forum. Ask a mate to help you, you may need more than two hands.....If I could do it you too will manage to get it fixed. Am sure.


Take off the upper plastic part which is held by the two metal tabs, just slightly bent them away with a screw driver, then take off the upper plastic part. You will see two Phillips screws. Remove the two Phillips screws you can see on the upper side of the pump, then you can lift the upper part and tilt it slightly aside, but take care not to tear off the 3 cables. Also the distance bushings will fall off but these you can get back in easily. As far as I can remember the filter is just clicked in. I did not get it out first but after a while of trying to get the darn thing out it came off together with a black rubber part. Dunno what you 'd call it in English. It is also most important that when you reassmble the pump that you check if both tiny o-rings you'll find on the aluminum tube are in place. I put some petro jelly on them, as I did with all other rings. Its a damn job to get the filter and the black rubber part back in. I was afraid that I could break it but I managed to get it in after a while. It would be helpful if anyone could assist you and at least holds the upper part aside so that you can use both hands to get the filter out and back in. Long nose pliers may also help. I fixed the pump in a vice but it was nerv-stretching. However, it took me less than 90 minutes to get it back into the tank so I am sure you'll make it.

Let me know if you could fix it.

Cheers Steve
 

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I have done my filters a few times and its a doddle (actually did it at the side of a mountain road in France in the rain once). The large outter filter 'bag' just needs to be opened out but to get to it you need to pull the filter body in half. Theres another smaller inline filter inside the body of the pump which sort of makes you wonder why the bag is there? I rode my bike for ages with the bag removed just relying on the inline filter. Have replaced it now though.
 

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I have done my filters a few times and its a doddle (actually did it at the side of a mountain road in France in the rain once).
There's a man who loves his bike :)
 

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I have done my filters a few times and its a doddle
If ya have hands like a south chinese midwife it may be a doddle ;o)
 

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I've got hands like shovels mate but I've had the filter apart a 'few' times as they say practice makes perfect. Was a bit disconcerting the first time I pulled it apart. Steady, you could get your dealer to photocopy the fuel pump stripping/assembling instructions from the KTM servicing book. I did that when I replaced my waterpump seal.
 

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Discussion Starter #19
Sorry new to this forum thing and didn't realize you were the guy who sent me in the right direction to begin with. Got the upper cap off and the inline filter. The inline filter came apart and had some really loose edges on the filter intself. Its a dodgy looking thing with little cracks in the upper edges. I've cleaned and dried it and will have a go at the lower filter tonight. If guys can change them on the side of the road I should be able to do it in my garage.
 

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I haven't 'changed' my filters on the side of the road mate just sorted out the problem of not revving over 7K. I'm pretty certain that its all to do with the outter bag type filter, when the fuel level gets low it collapses on itself and seals itself up. So if you take the top off the filter and get to that bag, you can pull it apart, throw it back together and hey presto. There is another 'inline' filter in the fuel pump so in theory the outter bag could be taken out.
 
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