Missing?

[brianm]

Hi all,i passed mod 2 today so this is the first chance i have had to go any distance on my 91 reg xj600,It has a problem,sitting ticking over its fine,in neutral it will red line no problem,but when you drive it it will rev to about 6 or 7 thousand and will not go any further,t seems to climb there and then it feels lke it is missing,the hardest i can get it to go is 80mph,in forth gear it will sit at just under 7 thousand revs and no matter how long you hold the throttle full open it just sits there and this thing i can only describe as feeling like it wants to go but something is holding it back,its had new plugs,air filter,oil.any help/suggestions would be greatly appreciated.
Cheers all

[pilgrim]

The only similar experience I had was with a Suzuki 400 twin. When I bought it I sped up to 60mph on a test ride but I only found the problem later having already parted with the CASH!!!!!!!

I turned out the owner kept topping the oil up without reference to the required level or quantity. Without any load the engine performed fine, but not over 60. I emptied it and put in only the required amount and ........Hey Presto! No problem after and no hidden fault with the motor. (Just a gutless bike after exciting 2T's)



Might not be your problem though, just one possibility to eliminate.

[arkwright]

It may be restricted...

[newell]

Yes, good thinking Arkwright. I would certainly be looking at a restriction in the induction side.

[brianm]

Thanks for the replies guys,I pulled back the inlet rubbers but its just the standard paper gasket in there,I also heard that the carbs themselves can be restricted,Where would i look on them for a restrictor?I also notice that the cdi has a small fan attached to it like a computer fan to keep it cool but would think if it was a cdi fault it would work or not work,Would i be right in thinking that way?cheers

[General Gman]

pull the carbs tops off - there may be spacers in there to stop the slides rising all the way.
As for the CDI having a fan on it.... never seen that (but then anything electrical is witchcraft to me)

[brianm]

Hi troops,I took the cover off the top of the carbs and nothing to restrict it there,Had it out today and she was fine apart from this acceleration thing,I thought maybe engine wear but no sign of it,starts firt time,no oil burning still returns 50 to the gallon,I know they are not fast bikes but there is slow and slow,its not so much the top end i want but if you want to overtake anything forget it lol,Anymore suggestions,keep firing them this way,i appreciate all your help. Cheers.