pistone broke... whos fault?

**Megazoid** · 9th February 2006, 07:36

i've had my 1986 FZR400 for a few months. it has always been smoking black smoke out of the exhaust . i could never figure iout why it was smoking and 2-3 times when i was taking it to fix various things that i broke, i was asking the guy at "KG Motorcycles" if that smoke is something to be worried about, but he told me that it's just gunk because the gas in new zealand is not very good, and that i should take it to the highway and to rev it out once week or so... so i did, and one week i put a lot of strain on the engine, then stopped for 10 minutes, and when got back on the bike, the bike didnt sound right, and i reved it a little, just before the red line one of the pistons broke in halfs... now my friend told me that my valve has been bad for some time now, and that i should have had it checked...

so that's why i'm posting here... is it guys from KG Motorcycle fault that he didnt checked the valves all tho i've told him about the smoke, and asked him directly if that could harm my bike... do i have any chance of getting any money of him?... cause i've spend sooooooo much money on that bike... just last week i've changed speedo, front tyre, and tuned carbs all together like 400-500... and now the bike itself cost like 1000 tops if i sell it for parts...

**SimJen** · 9th February 2006, 07:47

It sounds like its your fault for wringing out an old bike.
Were you willing to part with big bucks to get KG to strip the motor and check for worn parts?
Machines don't last forever, no matter how much they are looked after.
With an old bike the smoke would likely be caused by worn rings or valve stem seals. If the ring broke it could jam in the bore and cause a piston to break.

**Megazoid** · 9th February 2006, 07:50

yeah... but that's the point... i didnt know what was the problem, and the dude told me that the smoke is totally normal... i could have changed the rings... but now the whole engine is a pile of garbage

**imdying** · 9th February 2006, 08:00

Originally Posted by Megazoid

i could never figure iout why it was smoking and 2-3 times when i was taking it to fix various things that i broke, i was asking the guy at "KG Motorcycles" if that smoke is something to be worried about, but he told me that it's just gunk because the gas in new zealand is not very good

Well, that 99% of motors you see about town not doing this should've been an indication that this was untrue. Heh, KG motorcycles eh... back when I was a youngin and a group of us were cruising about on bikes, even then KG motorcycles was one place you didn't wanna take your bike

**marty** · 9th February 2006, 08:13

free revving a 400/4 to redline? that obviously had a problem? no wonder it broke.

black smoke - probably running too rich. nothing to do with rings/seals etc. the garage guy sounds right that it was a fuel problem.

how much did you pay him for this written opinion that your bike was ok anyway?

**T.W.R** · 9th February 2006, 08:17

Sounds like both of you are in the bin over this one.

Having a older bike that you know isn't 100% & still wringing it

KG for sayin what they did (old fallacy of days gone by, mainly 2strokers took heed of that rule)

Black smoke is usually indicative of being over-rich, Blue smoke is oil related and without doing an explority its hard to pinpoint an area where the damage is

**Megazoid** · 9th February 2006, 08:18

what written opinion?... it wasnt a written opinion... but i had my brother with me, and my friend when he said it

it wasnt running rich... the carbs are juuuuust tuned... perfect...

**Megazoid** · 9th February 2006, 08:19

thanks for all your help guys... oh btw, anyone needs fzr 400 parts?... quite cheap

**SimJen** · 9th February 2006, 08:37

If it was the valve a compression test would have confirmed. But a lot of old bikes smoke.
Not really the place to publically blame a company, take the issue with them.
I know what they will say.....

**Motu** · 9th February 2006, 08:58

Screw him for all he's worth - that'll teach him to become a motorcycle mechanic and think he'll get pleasure out of fixing bikes for other people...take him to the cleaners,who cares if it's your fault - that's not the point.

**imdying** · 9th February 2006, 08:58

I have a friend in Chch with a few FZR400 parts, quite possibly an engine, PM me.

**Sniper** · 9th February 2006, 10:24

Mate, your fault unless you asked the guy to take apart the motor to find out whats wrong. He did as you asked, Im sure you would have been annoyed to find out that he took apart your engine to see what the cause of black smoke was when you were only expecting a tyre job

**marty** · 9th February 2006, 11:06

Originally Posted by Megazoid

what written opinion?... it wasnt a written opinion... but i had my brother with me, and my friend when he said it

my point exactly

Originally Posted by megazoid

it wasnt running rich... the carbs are juuuuust tuned... perfect...

so if it wasn't running rich, why the black smoke? it's not oil, must be fuel. i'm pretty sure the carbs on my scooter are tuned as well as they can be, and i don't get any black smoke. ever.

**slob** · 9th February 2006, 12:21

Originally Posted by Megazoid

... but now the whole engine is a pile of garbage

This could be the perfect opportunity to stick an FZR600 (or even better a YZF600 Thundercat) motor in it! Heaps of people do this as the 400 motor and 600 motor have almost the same dimensions. You'd want a complete wrecked bike though as you need the rad, carbs and airbox off the 600 too.

**R1madness** · 9th February 2006, 13:57

Hey man i have a FZR400SP exup that is sitting around that i would be happy to strip out for ya. Motor runs good. Make me an offer. either for the motor or the whole bike.

Ian 021 1876987 or 03 9816399