n00bies first post

Hello.. Nice forums, just got myself a second hand 1998 wr400f, needs some tidying, but is ok in general. I've read through the posts, some great info there, thanks to those who contribute.

I'm just riding the bike to work out what needs sorting, gonna pull her apart next week.

Re the YZ timing, are there any drawbacks to doing this ? as I want the power increase, but do use the bike to plod about by road to the various dirt tracks/beaches and dont want to sacrifice road rideability/reliability for a bit of extra power..

The bikes allready got a comp exhaust and from the posts I've read I reckon a previous owner has removed completely the throttle restrictor pin, hence I get a pop and bang, hesitation occuring mainly on the road accelerating using full throttle. The misses start to occur about mid way thru accelerating and decreasing the throttle seems to smooth this out.. maybe its another problem ? (havent taken a spanner to her yet, so maybe the plug needs replacing)

Although its got comp exhaust, the airbox lid looks to be intact, so i'll give removing that a go.

Havent stripped the carb yet, but I expect it to have standard jets. More on that once I know what its got now I guess..

Whats the Gray wire thing I've read mentioned, is that a wr450 thing ?

If anyone wants to give me a basic starting point check list I would be most gratefull..

I noticed the archived forums arent accesible, shame cos there is some posts in there I think I need to read.. :)

Conditions here in Portugal are dry and dusty mainly, just above sea level as I'm by the coast, temps usually around 25 - 30c..

Make sure you grease the steering stem and all suspention linkage.

currently waiting on a manual from England, so today I stripped off all the bodywork, tank etc to have a poke around and check the plug.. Hmm, plugs pretty deep in there ain't it !! gonna have to get a special wrench from Yam I guess ? so i didnt get to check the plug, but all looks pretty good for a 4 year old bike..

I cant really tell yet what previous owners have done to it, I suspect its got regular wr timing, standard jets, although someone has thrown a comp silencer on there, so I guess thats what the popping and banging is when i open up the throttle, needs jetting no doubt. The airbox is allready missing the inspection plate, I took out the rest of the lid and got some amazing flames out of the exhaust, did rev easier, but sounded awfull, so I put it back for now till I can check on jets.. Am I right in thinking the big backfiring and flames is down to jetting ? on the road under low to mid range throttle the bike runs like a dream, its just when I try to open her up that it pops and bangs, but I can increase speeds by slowly applying more throttle..

Thanks for the tip on greasing, will do that.. Gonna pull her apart properly when I get the manual..

What spark plugs are recomended by you guys, standard as from factory or ?


before removeing your plug lift plug cap out of the way put plenty of wd 40 down in the plug reeses and use a smokers pipe cleaner to make sure the water drain hole on the right hand side of the head is cleer of any dirt or muck of any kind i have a freind that did not HE NOW WISHES HE DID takes five mins and could save your motor.

you will have to leen your bike away from the side stand to drain from this small hole

cookeye uk

Thanks cookeye.. :)

Yes it can get a little crusty in there

I always spray wd-40 in the head hole after rideing

Souds very painfull :)

Because you removed the throttle stop completely the trottle travels to far and the tps gives you a bum redeading and changes the timing. Put in a 23mm stop and that will solve your popping at full throttle.

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