GSXR250 engine won't start

[Tomas02]

Hi,
I don't own a bike but am building a go kart with a gsxr250 engine
have wired it up over last few days, and connected fuel lines, radiator hoses and other things.
I've now come to trying to start it, but it wont start at all.
The engine has good spark, just no fuel getting in as plugs remain dry.
One thing I don't have is a fuel pump, is it absolutely necessary? am trying to gravity feed the fuel at the moment, was told it would be fine.

Really just wanting to know what should I be checking next?
Am very new to motorbike engines

[ducatilover]

Clean the carbs.

[Tomas02]

Carbs have been cleaned today still no luck

[ducatilover]

Did you remove all the jets and inspect them carefully?
Did all the air passages get cleaned and are the float heights set correctly?
Are the air vents to the bowls clean?

[Tomas02]

yes checked all jets and cleaned them
not sure about vent to bowls
will check that tomorrow

[ducatilover]

yes checked all jets and cleaned them
not sure about vent to bowls
will check that tomorrow

While you're doing that, re-check the float heights, the fuel passages in the carbs and compression.
I assume you have fuel in the bowls?

[Tomas02]

Yes fuel in the bowls and i will check all of that
Also will it run alright without a fuel pump?

[ducatilover]

Yes fuel in the bowls and i will check all of that
Also will it run without a fuel pump?

It will run. The fuel pump is only supplying fuel to the bowls, my 600 only runs a vacuum fuel tap. The pump just makes it easy to start after the bowls have been dry.
If there floats are correct it will be:
Blockage in an air passage.
Blockage in a fuel passage.
Massive air leaks.
Blocked jets.
Low compression.
Super tight intake valve clearances/stuck valves.


One way of cheating and making the fuel lift is to blow very lightly into the vent tube.

[hayd3n]

spray start ya bastard into the carbs?>

[Tomas02]

cleaned carbs again today and adjusted floats.
using start your bastard spray its getting very close to starting.
how do I adjust valve clearances?

[ducatilover]

Find/download/steal an owners manual. I suspect it will be bucket under shim which requires removing the cams.

Are the spark plug gaps correct and what are the pilot screws set to?

[nzspokes]

Pull the plug, pour a little petrol in and refit plug. If it fires for a sec its carbs. If it doesnt fire the eletrical.

[ducatilover]

Pull the plug, pour a little petrol in and refit plug. If it fires for a sec its carbs. If it doesnt fire the eletrical.

Or valve clearances, or compression. Slightly low compression will fire like that, but not create enough vacuum to pull fuel from the carbs.

[Tomas02]

Unsure on all of this so I've given up and am just going to take to the local suzuki dealer.
might punch a hole in the wallet but at least they'll know what theyre doing.

Will update you on what happens

[lone_slayer]

just keep spraying start ya bastard it should be able to run on that alone.... my gsxr250 takes forever to try and start if its been left for a while & start ya bastard does work..... if it wont start on that stuff its more than just fuel supply...