Dealing with clutchslip

Hi all,
I'd be grateful for any advice on the subject. The bike is a UK
1978 RD 400 D, and the previous owner swears blind it is a fairly
new clutch. (No more than 1500 miles). It tended to slip as a
full throttle powerband kicked in, but it wasn't particularly
noticeable if you weren't too harsh with it. Enough to be
annoying though, so I have just adjusted it in the way that the
Haynes manual suggested. This has improved the feel enormously,
and for a little while, I almost thought I'd nailed the problem,
but then a 3rd gear flat out burst suddenly had the clutch
letting slide very noticeably.

The previous owner says he can't remember the exact oil he put in
the gearbox, but it didn't sound as though too much time and
attention to detail went into the decision making process!

My question is, should I try and change the oil first of all,
then where should I get the ideal oil and what'll it be, then how
long do you think it would take for the contaminated clutch
plates to rid themselves of the oil that might be making them
slip? Is this plausible as an explanation for my woe?

Alternatively, should I just get new clutch plates now? I've only
done a couple of hundred miles on the bike in this state, so I'm
hoping that's few enough to have retained some life in this
clutch.

Any advice would be very welcome, even the stuff for comic
effect, and I can only swear that when I have enough knowledge to
help someone else on this newsgroup, I'll do that.

Cheers, Nev

 

Nev Arthur wrote:

I'd replace the oil first, yes. RD400 gearboxes run on 10/40 engine
oil, IIRC, but Lozzo will be along in a minute with chapter & verse.

Putting something like EP80 or EP90 (used in some two-stroke gearboxes,
notably MZ) would certainly cause the clutch to slip. 20/50 might,
even.

The small amount of EP remaining after an oil change wouldn't do any
harm or contaminate the 10/40, so no worries there.

At the same time, check th clutch cable adjustment and routing.
Sometimes the silliest things....

If an oil change doesn't sort it, then it's time to look at the clutch.
It depends on what he means by "new clutch". New plates are often a
waste of time without new springs, and vice versa. Or he could have
stuck a really cheap set of pattern plates in.

Buy genuine Yamaha plates and springs - the extra cost is so small,
really - and fit thm together. Easy job.

 

You are getting old Tog!
One boils the friction plates in bleach for 5 minutes then make sure it's
the right engine oil. Usually does the trick.

 

Nev Arthur wrote

Yes, Halfords cheap bike oil[1], it varies, yes with qualifications.

Not yet. It may be the oil, or it may be weak springs, or the ****
could be lying his bollox off about fitting the new plates. Do what you
can outside the engine first and that will give you time to negotiate a
new mortgage for the internal bits should it need them.

Do make sure you have read and taken notice of the ukrm ffaq before
replying.


[1] Listen to wot Lozzo says, he might be a skinny little spic but he
does know his oil.

 

'Hog wrote

Never heard that one before.

<fx: checks poster>
Presumably this is some bodge it and run pikey solution?

 

Is there a similar trick for the opposite problem? My Fantic clutch
plates glue themselves together if I leave it for a few days. Sometimes
riding around with the clutch in & stamping on the back brake frees
them off, but usually I have to whip the engine out & prise the plates
apart.

I've tried gunking them & using different oils but no luck so far. New
plates aren't an option unless somebody can match them up with a
different bike from a photo - one of the 'joys' of owning a unique bike
:-/

 

Well it was a SOBB thing but it workes on RD's

 

i had the same problem with my vfr400 i had to replace the pressure plates
as the clutch nut came lose dont think it was spiked proply and half of my
pressure plates got burnt i brought new pressure plates soaked them in
engine oil for a few days then fitted them its now as good as new

 

CHRIS GRIFFITHS wrote

Whereas I have problems with top posters.

Now **** off and read the ukrm ffaq, paying particular attention to the
bit about acceptable posting styles.

Do hurry back please.

 

and where the **** is the ukrm ffaq

 

'Hog said...

I've done that before and it works. In the past I've just given them a
squirt of carb cleaner and a wipe down then bunged them back in, that
worked for about 20K miles on one bike.

 

Have you heard of google, you semi-literate oaf?

Shit, as soon as you see a name in upper case you just know the poster
is going to be difficult.

 

Nev Arthur said...

<Happy dance round the office>

At last, someone who knows it's a D not a DX.

Yip-yip-yip.

 

Fucking Google for it.

 

CHRIS GRIFFITHS wrote

On a web page somewhere.

 

said...

TOG's right, with the exception of buying new plates. Hog and I give
reasons why below.

NEVER use 20/50 in an RD400 gearbox, it'll make the clutch slip for some
reason. I use the cheapest and shittiest 10/40 mineral oil that I can
lay my hands on. Halfords do one dirt cheap.

You may want to replace the 6 clutch springs at the same time, chances
are they've never been replaced before and they will be shagged by now
if the bike has been used alot. While you've got the clutch apart, check
the sides of the ears on the clutch basket. If they are a bit uneven and
have indentations on them you might either need a new basket, or if they
aren't too bad you can clean them up with a very smooth file. You'd need
to remove the basket first though.

This bike isn't a yellow one registered WYF 68S is it?

 

Nev Arthur said...

ROFLMAO!
Actually, since you told me it was D, I've been annoying people
arguing with them over their mistake in thinking it's DX! Great
fun really!
Can I just say thanks to every one who responded to my request
for help, please don't be offended if I don't reply to every
poster who made useful suggestions, but I have a life, ;-)
Nev

 

In an old book I have, it tells me to use "branded SAE 10W30" so
I don't know if you can still get that specific type?

The previous owner thinks he might have used 20W50 but didn't
sound too sure to be honest.

OK. So perhaps I should only try the bleach trick that someone
else mentions if I still get no joy.

The routing looks OK to my eye, but then I don't profess to have
any skill at it.

Again, I don't like to keep hassling him, he's one of the
traction inspectors where I work, so best not to annoy him eh?

If they're still all available, that would be my plan, if needed.
Many thanks for the help.
Cheers, Nev

 

I'm finding it tricky keeping a relatively common bike like the
RD on the road, how the hell you can derive pleasure with
something as rare as that...! Oh well, No gain without pain
huh!
Cheers Nev

 

You all happy now you bunch of greasy road hogs watch out for them man hole
covers.