power loss...

[Specter]

hi all

got my bike up and running havn't done anything to the motor, but from when i started to now it has lost a heap of power, its struggling to hit 110, when it would easily do 160 before... would you have any ideas as to why this is?

[Gix11]

Got it up and running since when?

Have you changed the pipes, airbox, any ram air, sprockets......?

What bike is it? Carbie or F.I.?

Not much info for us to help. Give us more details.

[BANDITROD]

more details mate what bike etc....

[Specter]

its a ex 400... carby motor... nothing changed as of yet.... everything is stock standard.. um look at my other post at

http://www.streetfighters.com.au/forum/topic.asp?TOPIC_ID=15546

thats the bike...

thanks again

[80s freak]

How long since it's been running?

[BANDITROD]

this may or may not be your prob but i know a bloke that had the exact same prob and it was his plugs when he replaced them he done them up finger tight and then got side tracked and forgot about them at first i thought he had done a head gasket but then soon noticed the plugs bouncing around when he revved it ...like i said prob not the issue but worth a look

[livewire]

Back to basics.
Compression.
Spark. (including advance)
Fuel. (old? filter?)

[latheboy]

I started my EH after it sitting for 5 years ( with 5 year old fuel in it ) and it drove like a pig, would rev past anything..
I was suprised it ever started because petrol has a shelf live of about 3 weeks before all the octane goes away.
New fuel and plugs, and look for little monsters in the airbox, spiders or wasps might have moved in.

[Supercharger_Mark]

I was on one of the annual Gravesend fangs a couple of years ago after the bike had been sitting for a few months, it was running like a pig, A fucken rat made its nest inside the air filter, ran great after I cleaned it out.

[Tony Nitrous]

Used to have a similar problem with some of the bikes
(but not others...go figure?) that sat through the English
winters.

Put it down to fuel.

Was also told that when they changed to unleaded the chemicals
and crap in the new stuff will gum up jets etc after sitting in
storage. Not sure how true it is but the bloke who told me was importing
old stock 2nd hand jap 400's in the UK and everyone had to have
the carb's pulled off and cleaned.

...........but then again it could be all B.S. ?

[80s freak]

Gumming up of the carbs can be a real drama, ultrasonic cleaning is the best way to get rid of it.More food for thought, check for a wasp nest in your muffler, seen afew of them over the years.

[The crow]

The old man has an old xs 400 which had a similar prob and i agree with the above, FRESH fuel and use premium unleaded check plugs and air filter and the jets may be a little sticky from sitting so the fresh fuel will be good and even a little stp fuel carby cleany will help.