gpz600r not on fire

[4130]

gpz600r 1985
gets fuel (pulled the plugs and they wet)
has spark (checked and has it)
turns over and does not fire.
any ideas

[mike-s]

hows the compression?

[4130]

dunno will try to check this weekend.
would there be anything else to consider?

[Gosling1]

your valve clearances are too tight. Probably the inlet valves. Poor (or non) cold starting is a classic symptom of tight (or non-existent) valve clearances......

thats the first thing to check. There are other reasons for low compression , but lets not worry about those for the moment.....

If the valves need adjustment, I think the little geeper had screw/locknut adjustment ? Its a piece of piss to do.

Next thing to check is battery voltage while turning the engine over - you want at least 12.5v or more when cranking.

See how you go with valve clearances first.

[Smitty]

as Gos sez

but wots with wet plugs?
either its flooding (carbs ? blocked air filter?)
or spark is weak
or valve clearances are shite (yeah Gos..screw and locknut )

wots been done recently to the bike?

[4130]

new plugs
new air filter
new oil and filter
all within 1000 kays
unsure of other work as i just picked it up
was hard to start cold (battery or clearances)

[4130]

unfortunatly i don,t have a manual so a little unsure on doing the clearances.
any tips?

[mike-s]

not sure exactly but 0.10mm should be somehere within spec for any bike. specs for most bikes usually sits between 0.07 & 0.17mm. if you opt for 0.10 then it may be a bit closer together for the exhaust valve than is preferable. Also a trap for new players (myself included in being caught out by this at least once) is forgetting to correctly check the clearance after the locknut was pinched tight, not a good thing to do!

[4130]

is there a downloadable manual or link that anyone knows of.

[Ratmick]

http://tinyurl.com/5b3qzc

I have nfi if this still works, my work internet police block the site.

Mick

[4130]

awesome downloaded and gives me something to do when not drunk(maybe easier if i am)

[4130]

inlet valves are to tight.
how wrong can i get it and whats the worst that can happen.
will try over weekend.
thanks guys

[mike-s]

If it's too tight then theres a possibility that the valves dont close if they have zero clearance when hot. Not closing means that they can overheat due to 1) continual exposure to flames from the ignition on both sides and 2) no surface contact with the head to allow excess heat to effectively disperse. Oh and then there's the fact compression is reduced, effective airfuel load reduced and generally the whole thing being totally mechanically unsympathetic.