hi all. just been out on my 300 been running fine inmid range 8/10000ish but when used to max 12000ish after a few minutes the engine slowsand wont really rev after another minute or so its ok again but if used hard repeats itself again. havent looked at anything yet but on arival home everything seems ok,ie rev up ok no noises etc. any help appreciated thanks

has it had the wire splice done ?

thanks for reply ,yes it has had wire splice done

My first guess would be fuel starvation.

Blocked tank filter? Knackered hose from tank to carbs? Blocked vent for air to get into tank as fuel drains out?
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MC21SP Plaything
BMW F800GS Bumblebee
Triumph 9551 Daytona Big boys toy
FJ1100 Sporting relic
GTS1000 oddball

Yep. Check the float heigh.
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james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

just thinking on mine was doing the same thing last week cleaning the air filter should do the trick mate

just checked tank breather,fuel filter and line all seems ok.had a new air filter earlier this year also float hieghts were checked ok.cant help but think that its running rich [210] main jets no power jet,although its oatmeal colour when plug chopped.what you think.thanks sofar

i had a similar problem on an 18 where when i put the tank back on i tristed the fuel hose. it ran fine till it needed fuel for any period of time.
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94 mc28 SE

Check to see you have full, unrestricted flow of fuel to your carbs when the fuel valve is open (turn the valve on and visually check there is free flow at the end of the line to the carbs). You could have a restriction in your fuel petcock, line, or tank filter.
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Paul Herr
'88 FZR4/GSXR/YZF Frankenbike
MY BIKE PICS

Yep I think its fuel too. I went out yesterday with my new body work ( which looks SWEET thanks TYGA ) Anyway the tank that came with had a little crap in it that I tried many methods to remove and while I got most I don't think I got it all. My bike was doing the same and then it got really bad and I switched to reserve and it was back to just a little sputtering. Sorry for the novel but yeah I think we both have a fuel problem.
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1995 A kit TZ 250
1994 Rothmans NSR 300sp SOLD
1998 RM 250 freestyle/motorcross
1998 Meathanol burning CR 500 AF super retard/motorcross/sand dunes/play bike

Well let see a pic of your new bodywork

fstnsr wrote:i had a similar problem on an 18 where when i put the tank back on i tristed the fuel hose. it ran fine till it needed fuel for any period of time.

Come tho think of it I did a similar thing on my GSXR many years ago. When I put the tank back on after a service I pinched the vent hose for the carbs and it wouldn't run right. Cost me a race and took a while to figure out.
_________________
james
Its not how fast you go...Its how you go fast.
MC21 Rothmans
RS250
RC31
CRF250X
748R
Porsche (many)
http://members.rennlist.com/j911brick/rennlist3_002.htm

are you using quick release valves between the carb and tank ?

I had a similar problem, the release was tight, but didn't flow enough fuel. A reconnect, making sure it seated, solved my problem.
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom