Derbi Gpr 50 - Not revving

[snowdude2004]

Finally sorted out my exhaust a week ago and its been running fine since apart from it was having problems from about third gear changing up since revs were at about 10k and would not go up. Figured out the front sprocket had an extra two teeth so need to go back to standard.

I went for a long ride yesterday with some mates and pulled up at home. When I went to start it again and pull away it was at about 3k revs and was crawling, barely at walking pace when using the throttle.

I checked the airbox and cleaned out jets on carb which seemed to be fine anyway and put it all back together today and I'm still having the same problem. Its now idling though but still only revving to about 3k.
Tomorrow i'll take off the exhaust and look through to see piston/piston ring to see if there's any damage to it.

Any other ideas/solutions to solving this problem guys?
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[N cee thirty]

maybe your exhausts blocked up,on my rs it blocked and wouldn't rev over like 5k,but if you have a new exhaust then probs not
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'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[dobby]

Is it restricted or derestricted?

[snowdude2004]

I believe its derestricted, I didnt see any restrictors and its going about 60 or so anyway.
Checked piston rings today and was 100 percent fine. Started it without the exhaust and seemed to have some power, didnt have it on long though obviously since the neighbours would murder me. I believe its something to do with this gianelli exhaust, is there anyway of unblocking it at all?
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[N cee thirty]

[snowdude2004]

Cheers Rob, will buy some from the Chemist tomorrow hopefully.
Any idea why it would only just conk out now in one go though?
When taking the exhaust off it was full of gunk which wasn't there before and I have used the recommended amount of redex in the tank about one tank full ago.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[N cee thirty]

[Trylski]

B&Q do it, I de coked my Gpr exhaust couple years ago, mine did something similar to yours. It would randomly just stopp revving properly. As if it was fighting with itself. Was rideable, wouldnt go over about 4k revs and constantly died. Turned out the coil had packed in. Might be work checking.
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Current Bike: Suzuki Bandit N600 '99,
- CBT: Passed 02/2008 - Theory : Passed 24/02/09 Test: Passed 09/03/09 - 2011 33bhp over

[snowdude2004]

Cheers guys very much appreciated, luckily I've got a spare cdi coil so will try that as well after de coking exhaust.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[snowdude2004]

I managed to get caustic soda today and shoved about 4/5 litres in the exhaust to fill it and rinsed it out a few hours later to only get some slightly coloured liquid out.

I've now re attached the exhaust and still seem to be having issues and now I'm kind of stuck for ideas, anyone think they might know?
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[N cee thirty]

[snowdude2004]

I left it in for about 4 hours (even though bottle said 30 minutes) and mixed 125g with 5 litres like it said on the bottle. Took about an hour to fill it up since the small pipe at the end trickles water through.

Just started it up via bump start since electric isn't working now (I raped the battery) and it goes about 1.5k revs and cuts out in less than 10 seconds each time since the throttle isn't responding at all unless I whack it on fully and quickly I can keep it going for a few more seconds but the revs aren't increasing when I do it.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[N cee thirty]

[snowdude2004]

Will get that done tomorrow then since I'll need to borrow a friends battery charger for that.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[prawny1]

put a new spark plug in, sounds like its burnt out, other thing I would check is the reeds.

[snowdude2004]

[snowdude2004]

[snowdude2004]

[snowdude2004]

[snowdude2004]

spanny = expansion chamber right?

just going to the garage to check it all now, shouldn't be too long.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[snowdude2004]

Thought so, not up to all the slang for bikes yet still fairly new

Just checked the big rubber hose going from carb to reeds and that seemed intact. Went to the top of my road and bump started it and it went to 1.5k revs each time and cut out. Let out a deep groan each time I tried it. Suppose i should but the airbox back on now.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[Paxovasa]

Is there a fuel blockage?
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Suzuki GSF600 K3 (in the fastest colour, black).

[snowdude2004]

I took off my petrol tap and tilted carb when throttle cable was out of carb and petrol was coming through both.
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[snowdude2004]

Just called up a semi local garage called revs where they have a pretty dam useful guy and they've said to now check compression and electrics with a voltage meter and also to check magneto, they said they just conk out over night so seems like the most logical problem now.
Being 16 and owning none of those semi specialist tools means I may have to end up pushing it about 2 miles to get it to the nearest bike place to do that for me
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23

[snowdude2004]

Wires seem to have had problems in the past but seems to be all in fine. Heres a couple of pictures which might help you more.

https://i31.photobucket.com/albums/c376/snowdude2004/CIMG1094.jpg

https://i31.photobucket.com/albums/c376/snowdude2004/CIMG1096.jpg
____________________
CBT passed: 26/09/09, Theory Passed: 18/08/10, Mod 1 passed: 20/10/10, Mod 2 passed: 26/10/10.
Current Bike: Honda CBR 400 Nc23