Question for themotorhead/ Johnny Cheese

[OB_NumbNuts]

TMH / JC
Please help!!
I have nothing done to my bike at all. not a stitch. totally stock. 5250 miles, mobil 1, and thats it. Runs like sh1t at idle to about 4k rpm, surging, hunting etc. throttles off at about 2200rpm without asking while rolling on power(Very unnerving at junctions and roundabouts.) and sometimes 'blipping' throttle gives nothing.
Dealers over here just tell me its normal and to keep the revs up. They are all a ****** joke. I know its not normal.
If I was to do the airbox mod, would this fix it? (I am presuming it is all to do with the flap in the box opening and closing)
If I am wrong, what would you suggest.
Apart from this, the bike accelerates like a missile above 4k rpm, although the gearchange is sometimes gratey 3rd to 4th only going up box, when warm, shifting at around 4 - 5 k rpm, all weather conditions.
TPS is spot on, line going to top at 2000 rpm, TB's sync okay, I don't think I've missed anything, oh yeah, oil catch tank drain drained and air filter clean, air filter water trap drained, idle set anywhere between 1050 - 1250, no change.
Bike is '99 model, UK spec Blk & charcoal
This is the only problem with a mindblowing machine.
Thanks in advance
(have manual now so I know where bits are located, am an engineer so can fiddle competently!!!)

 

[OB_Johnnycheese]

Putting the mod on before you fix your problem is not what I would do.
when you checked throttle body sych.
did you hook up all hoses to the proper spigot?all vacuum line going where they are suppose to?
Start there If everything ok I am alittle puzzeled at this point.

 

[OB_Tangram]

Had much the same on mine, '99 model. JCheese suggested 'look under the tank' and behold... a fuel return hose with a 160 degree bend in it! I solved the issue by cutting off the offending inch of f****d pipe.

Have a good look at the fuel system, under-tank hoses and fuel-filter mod (I'm Getting mine done on Thursday) and all will be well. You're right about dealers though. I'm sure there are some diamond geezers out there, but mine too is a shite!



[This message has been edited by Tangram (edited 15 May 2000).]

 

[OB_NumbNuts]

Thanks for your help chaps,...
JC
I did it a little wrong to start with, but having spoken to Lyle, (before my manual arrived) he set me straight with the correct procedure.

Tangram
I have noticed a slight 'weak point' in one of the fuel hoses when the tank is raised, but cant really tell if this is the problem when tank is lowered. I will try getting a flash light in there tonight when all is dark!!

I will let you know how I get on

Thanks again

NumbNuts

 

[OB_THE MOTORHEAD]

yes thats where they tend to fold because of all the crap in the way.if its a 99 86 the black crank breather tank.this gives the lines a little more room to bend without folding