Bit o' trouble

[el_scor_cho]

Hey, im having a bit of a problem with my fzr 400r 1991, but i think its quite a general question. I seem to have 'used' 1litre of oil over 1500k in the last month, it has done 50 odd k's all up, but i don't think that is a factor. i have been checking the level over the last week and it hasn't moved since toppin' her up. just wondering is it possible for a 15 year old bike to do this? Also, my main problem is that five or six times over the last few weeks the bike seems to have 'slipped' into neutral or just dropped out of gear just after giving it a bit of gas then letting off she seems to cut out. the engine remains on but it is not until the clutch is pulled and changed back down to first or second (amidst painful crunching noises) and dropped into suitable speed that she goes like normal. this seems to be quite an issue and any help would be great. Could it be plugs or just a worn clutch? Cheers

[idb]

It sounds to me like you might need to look at your clutch.
Does the bike try to creep forward when you've got it running in gear and the clutch in?
Easy things first, check to see if you have got any adjustment left.

That is a lot of oil to use in 1500ks, I'd imagine you'd notice smoke at that rate of use.

[Pancakes]

If there's not a pool of oil under the bike and your mates haven't named your ride "The crop duster" then you haven't dropped it or burned it. What makes you think it's that volume of oil and who else has access to your bike?

[Paul in NZ]

Oil use? That sounds very odd but it could have pushed some out of the breather up into the airbox so I'd give it a new filter and change the oil filling with the exact amount and go from there.

Is it jumping out of gear (Yamaha gearbox's are not the greatest) into a false neutral or is the clutch stuck? A bit more info would help with diagnosis.

First thing is to check the rear chain tension and see if there is any crud build up around the front sprocket.

Cheers

[vagrant]

Is it doing it it any particular gear?
From what you are saying with it "dropping out" after applying and releasing power, it seems that the dogs that hold the gears engaged with each other may be worn. The shift forks that move the gears sideways may also be a bit tired.
This was the problem I found when my Fireblade began to fall out of 2nd gear.
The gear that goes first is normally 2nd. Its the one that gets thrashed the most, funny old thing that.
I'm afraid the fix for that is a gearbox rebuild. Not cheap.

On your oil consumption issue, you need to monitor it closely for a week or so (you are aiming to check it over a couple of hundred k's at least). Check the level in the same place each time, i.e park it in the same place each night, and check the oil level the next morning. This will take the random factor of bike attitude and oil gallery retention out of play.
Keep a note of how many k's you do between checks and the oil level at the time. Don't add oil until the check is over, unless it is below the low mark.

keep the engine and the inside of the fairings clean, this will help identify any possible leaks.

[kiwi cowboy]

have no idea on the gearbox issue but you havent got turning rings have you. I had a bike that wouldnt burn any oil for ages then suddenly burn it for a spell. Iasked a mechanic about it and he said the rings will turn in the odd engine and when the gaps line up with each other it will use oil untill they turn out of alighnment.
just a thought anyway good luck

[el_scor_cho]

Awesome, Vagrant, na its not in any particular gear but around 3rd usually, will give ur advice a go also. Paul, that would probably be the best way to put it "jumping out of gear into a false neutral", also i just got the air filter changed along with new oil so hopefully that will help will keep an eye on it though. Na it doesn't smoke what soever besides a dribble of black when started but nothing out of the norm with no one else having access to it. Also she doesn't try to creep forward when in neutral or the clutch engaged. Cheer for the advice, will give a few of those things a whirl and see how it goes.

[Paul in NZ]

I'm not sure if you can extract a FZR400 gearbox without splitting the cases... If you can it's worth doing, if not and you have to split the cases - it's going to cost PLENTY unless you are prepared to get your hands dirty.

The good news is, the engine can be removed in 4 hours easy. A bit of practise would see it out in an hour...

[vagrant]

Awesome, Vagrant, na its not in any particular gear but around 3rd usually, will give ur advice a go also. Paul, that would probably be the best way to put it "jumping out of gear into a false neutral", also i just got the air filter changed along with new oil so hopefully that will help will keep an eye on it though. Na it doesn't smoke what soever besides a dribble of black when started but nothing out of the norm with no one else having access to it. Also she doesn't try to creep forward when in neutral or the clutch engaged. Cheer for the advice, will give a few of those things a whirl and see how it goes.

Thats a classic symptom of worn drive dogs and/or shift forks. Its only going to get worse i'm afraid.
Losing drive when your leaned over coming out of a corner is a great incentive to getting it fixed.