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Help with carbs
Posted: Wed Apr 21, 2010 7:37 pm
by davecmorrow
Hi, over the last three months I have been rebuilding my engine (changed the head gasket). It is all now back together, went to start it and nothing happened. It looks like these is a problem with my carbs, there is no sign of petrol coming out. They have been taken off and clean and still nothing happens. Can anyone help me?????
Re: Help with carbs
Posted: Wed Apr 21, 2010 8:06 pm
by parby81
is the fuel pump working? can you see fuel moving along through the fuel filter. If they were empty they do take quite a while to fill up the float bowls, to the point it can flatten the battery just filling them.
Re: Help with carbs
Posted: Wed Apr 21, 2010 8:19 pm
by davecmorrow
I have taken the carbs of twice to clean. Both times they were full.
Re: Help with carbs
Posted: Thu Apr 22, 2010 12:30 am
by bendog66
Thought about checking for a spark? And parby is correct, it takes approximatly 30 seconds of constant turn over to get fuel though
Re: Help with carbs
Posted: Thu Apr 22, 2010 1:04 am
by lewisdale
throw some easy start down it
Re: Help with carbs
Posted: Thu Apr 22, 2010 7:43 am
by davecmorrow
I have put new plugs in and checked the spark and I have tried easy start. I know don't understand what is wrong with it. There is still no sign of petrol coming out of the carbs so I may now check the fuel pump. How fast should the fuel be pumped into the carbs???
Re: Help with carbs
Posted: Thu Apr 22, 2010 9:25 am
by lewisdale
if its not firing on easy start you must have problems elsewhere
Re: Help with carbs
Posted: Thu Apr 22, 2010 9:43 am
by davecmorrow
I am guessing that there is a problem with getting fuel into the carbs as I cannot see any coming out. I am going to check the fuel pump tonight to see if it is working. As the carbs are clean I cannot see what else could be stopping the petrol coming out of them?
Re: Help with carbs
Posted: Thu Apr 22, 2010 12:50 pm
by RedexRobB
so do you have a spark or not? When you changed the plugs were they dry or wet?
Re: Help with carbs
Posted: Thu Apr 22, 2010 2:01 pm
by davecmorrow
Yes the spark plugs were working. They were dry.
Re: Help with carbs
Posted: Thu Apr 22, 2010 7:21 pm
by parby81
As , I said at the beginning, Is there fuel going to the carbs from the fuel pump, you should be able to see the fuel moving in the fuel filter when it is being sucked through every few seconds at tick over. Alternatively, disconnect the tank, and then holding the tube from the tank and the tube from the carb at roughly the same level, with fuel still in the filter side of the pump, turn the engine over on the starter, fuel should spurt out of the carb side tube (suitable container to catch + no naked flames etc etc

), just watch your eyes, petrol and eyes don't mix.
Let us know the results
This can only be worked out step by step and a process of elimination
Re: Help with carbs
Posted: Sat Apr 24, 2010 10:08 pm
by davecmorrow
Managed to test the fuel pump, it is working fine. Then made some adjustments to the mixture screw and the carbs look like they are working fine. I now have a feeling that I have got the timing wrong. Can anyone describe or show me (in photos) how the timing should be set?
Re: Help with carbs
Posted: Sun Apr 25, 2010 11:23 pm
by extonyg
ye thats a possibility its out, hopefully not so far out its done any damage.
heres a link on how to check valve clearances but its got some good pictures to show you timing marks etc thought it might help.
viewtopic.php?f=55&t=8002&p=83205&hilit ... him#p83205