A little help? Pics included. 2002 650 melted piston?

GAVBEY · Jun 23, 2014

Hi guys.

I'm relatively new to husabergs. I bought mine 3 weeks ago.
I've been riding it about loads. I've changed the oil every 4 hours and checked the valve clearances every second oil change.

It's a 2002 husaberg fs 650
3250 km on the clock and it's had a full rebuild in the past.
I live in Shetland and there is only 95ron fuel here so I'm thinking that has somthing to do with it.

So when it happened..... I was heading home after a day out on the bike. Quite high up in the rev range I felt a bit of hesitation. Not a bang or anything just hesitation and as if the back brake was on. Strain on the engine.

I pulled in my drive and pulled in the clutch. It stopped instantly! I tried to kick it over but It felt real stiff. After a few hours I kicked it over and it started fine then again while it was idling for about 5 seconds it stopped solid.

I've recently modified the exhaust by cutting out the baffle and I haven't touched the jetting. I'm using a 190 main jet.

I started to strip the engine down to find the cause. I'm looking for a bit of help.

So here is some pictures of what I found so far.

GAVBEY · Jun 23, 2014

Here is the bike stripped down. Sorry for it being upside down.

Is this cam chain guide bolt supposed to be this angle?

This cam chain guide looks a bit broken?

Engine cover off. No major looking problems here.

I found this bolt to be loose??

The bore doesn't look bad? There is some marks of detanation on the piston though?

I was turning the engine over with a 17mm socket and t bar. I could feel a reall stiff spot at really random times. I thought I had spun a shell until I found out I don't have shells. I then soaked the barrel and piston in oil and after a good few rotations it got easy until the stiffness has gone. I can't actualy make the engine get stiff when rotated anymore.

I think I've melted a ring or piston?

How hard is it to change a piston on these beasts?

Look forward to any reply

Thanks. Gavin.

bushmechanic · Jun 23, 2014

Hi Gavin

if you haven't found the cause of the problem then you need to split the cases

it could be something like the mains or counterbalancer or big end

its not difficult to work on, just different to other bikes

manuals and parts listings here

Service Manuals - Husaberg Forum

owners docs

https://web.archive.org/web/20140116233253/http://husaberg.org/wiki/index.php?title=Main_Page

GAVBEY · Jun 24, 2014

bushmechanic said:
Hi Gavin

if you haven't found the cause of the problem then you need to split the cases

it could be something like the mains or counterbalancer or big end

its not difficult to work on, just different to other bikes

manuals and parts listings here

Service Manuals - Husaberg Forum

owners docs

https://web.archive.org/web/20140116233253/http://husaberg.org/wiki/index.php?title=Main_Page

Thanks for the reply bushmechanic.

I feel strongly that it's the piston and rings but I'll split the casing a for a better look. Christ I hope it's not the big ends. I'd need to ship away the crank!

I'll just need to find a flywheel puller. I don't want to use the 3 jaw ones but I'm not sure where I can find the internal one.

Thanks again.

Taffy · Jun 24, 2014

i would still feel for that tight spot. if you find it then mark the gears with a felt tip pin where the teeth meet. keep turning the engine and see where it happens again. could be that you have a 'bad tooth' on one of the gears.

if you do get it done at two thirty!

Taffy

bushmechanic · Jun 24, 2014

HUSABERG/KTM FLY WHEEL PULLER | eBay

zaga · Jun 24, 2014

Hi

I've seen one head with the chain guide like that and it was the wall of the head that twisted a bit.

Yours doesn't look that bad, check the screw and the hole of the head, maybe the impacts have slotted the hole and it my need a little fix.

Your chain definitely needs to be changed !! and at least one of the guides (clear one). You can also update the black one.

Cheers
ZAGA

GAVBEY · Jun 24, 2014

Hahaha taffy that cracked me up I was looking at the gears thinking 230 degrees then I just burst out laughing. I'm a tit.

Thanks for all the replys guys.

I'll check over all that. Ever since I covered the barrel in oil it's not gone stiff at any point. I can't seem to get it to go stiff anymore. I'm thinking some of the aluminium of the piston has melted near the ring and the friction of that is was causing the stuff spot and because I've put a load of oil in there it's all lubed up? Who knows.

I'm sure it will be fun to strip the beast down anyway.

Thanks for the advice zaga and thanks for the link bushmechanic

I'll keep this thread updated with pictures.

GAVBEY · Jun 24, 2014

So here's a little update of today. Basically I've striped the bike down a bit as I'm waiting for a puller.

Here's the bike without an engine

Can you see the scraping marks on the casing?
This is from the timing chain.

The ballance shaft sprocket fell off. Where should the dots be aligned with? Like any of the pictures below?

Or

GAVBEY · Jun 24, 2014

Is this a standard piston? The numbers are hard to read. 212....

Is there an uprated version of these? Could this have been a problem?

Timing chain marks on the top cover?

The head with gasket on.

And my pile of bits some cleaned some not.
Like I say I still think a piston and rings wouldn't harm it however the cam chain is quite suspect now. Hmmm

Look forward to any rely

Cheers
Gavin

edelweiss · Jun 24, 2014

the chain tensioner is ok, it was just full in, because of the loose chain. split the motor and dont forget to split the crank as well (to see the big end needle bearings cage). if you are considering just changing t-chain+guide+slide and tighten the nut with loctite and then sell the bike ("freshly rebuilt"), please dont do that. every single ******* bastard here in Slovakia would do that, but it woudnt be fair. be thankfull, because you were lucky. very lucky.

edelweiss · Jun 24, 2014

use IWIS or Tsubaki chain. look at the bottom of the piston if it is not scratched from touching the teeth of the water impeller shaft. if yes, the piston pin should have enormous play. this happens when stupid arogant mechanic installs non-original piston and does not check if it fits by turning the wheels a few times before putting the halves together. change both bearings on the water impeller shaft. the chain slide should be fastened more wisely. the updated (2004-2008) original solution for this is not expensive.

GAVBEY · Jun 24, 2014

edelweiss said:
the chain tensioner is ok, it was just full in, because of the loose chain. split the motor and dont forget to split the crank as well (to see the big end needle bearings cage). if you are considering just changing t-chain+guide+slide and tighten the nut with loctite and then sell the bike ("freshly rebuilt"), please dont do that. every single ******* bastard here in Slovakia would do that, but it woudnt be fair. be thankfull, because you were lucky. very lucky.

Haha no way! I have a highly tuned Mazda RX7 and an engine rebuild on these engine is a peice of pi$$ compaired to the rx7. That's one thing I've never understood. People selling there toys "after a rebuild". Normally if I rebuild an engine it means I'm keeping it known exactly what has been done.

Now splitting the crank will be a pain. I know that's a professionals job. I'm not sure who would be able to do that. Might as well be putting new big end bearing in at the same time.

GAVBEY · Jun 24, 2014

edelweiss said:
use IWIS or Tsubaki chain. look at the bottom of the piston if it is not scratched from touching the teeth of the water impeller shaft. if yes, the piston pin should have enormous play. this happens when stupid arogant mechanic installs non-original piston and does not check if it fits by turning the wheels a few times before putting the halves together. change both bearings on the water impeller shaft. the chain slide should be fastened more wisely. the updated (2004-2008) original solution for this is not expensive.

This is the chain I use. Is it possible that it's 1 link too long? I mean it didn't feel loose?

.

I wouldn't like to blame any mechanics as the engine was built by a reputable tuner. I blame the Shetland fuel so far for giving me det and breaking somthing. I'd be lucky if it's 93 Ron up here. I might consider a fuel boost substance like silcolene pro boost.

What is the 2004-2008 system like? And what price are we talking here?

Thanks for the reply.

Kayeffess · Jun 24, 2014

Top pic for timing one dot between the two.

https://web.archive.org/web/20140116233253/http://husaberg.org/wiki/index.php?title=Main_Page

There is lots of info here for your rebuild

Cheers

edelweiss · Jun 24, 2014

what is your ride? 400, 501? and how many links does the chain have? the solution is the bolt and nut which hold the chain slide the part is called stepped spacer bushing part. no.: 80036002050. its safer than bolt and nut. tuner and gives longer chain? come on.

edelweiss · Jun 24, 2014

400, 450: 64links, 501, 550: 66links, 650 70 links, 600 dont know for sure

GAVBEY · Jun 24, 2014

Thanks for the reply mate
Much appreciated.
I think I should go for a new chain then.
I have been out to check and it has 70 links and my bike is a 650 so that is right enough.

Here is two pictures of the guide bolt I have.

And here is it disembled.

The washer is aluminium.

Am I right in saying the early ones had problems and this is the newer version?

Thanks again

bushmechanic · Jun 24, 2014

looks like this sprocket ate something hard at some point
maybe previously broke a cam chain or had a tappet adjuster nut fall off

before you split the cases is a good time to check the squish and crank axial play, if it has any.

makes it easier when putting things back together

if you haven't already, read up on these manuals, 2005 manual is also worth reading, some things are explained differently.

http://husaberg.org/service-manuals/17602-2001-2003-husaberg-workshop-manual.html

http://husaberg.org/service-manuals/17760-2005-husaberg-workshop-manual.html

thanks for putting up all the pics, not many people bother

edelweiss · Jun 25, 2014

I think the sleeve should have thread inside and thus be something like 2in1 with the nut on its end. I just ordered the original part. when it arrives i will make pix and post. your solution is not so bad, the nut is a lock nut. the idea is, when the nut falls off, many disgusting things can happen. and it seems to me, something like this allready happened in your engine, somebody just put it together with minimum investment.

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A little help? Pics included. 2002 650 melted piston?

GAVBEY

GAVBEY

bushmechanic

GAVBEY

Taffy

bushmechanic

zaga

GAVBEY

GAVBEY

GAVBEY

edelweiss

edelweiss

GAVBEY

GAVBEY

Kayeffess

edelweiss

edelweiss

GAVBEY

bushmechanic

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