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Posted

hey all, halfway through the process of putting a 4k in my 20.

 

we have put the 4k in with the 3k starter motor, carby, fuel pump and alternator. the engine is turning over but it wont fire. now is the problem that i have 3k gear on it? the spark plugs seem fine and so do the leads. could it be my timing is completely out?

 

any light shed on the matter would be great.

 

cheer nick

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Posted
hey all, halfway through the process of putting a 4k in my 20.

 

we have put the 4k in with the 3k starter motor, carby, fuel pump and alternator. the engine is turning over but it wont fire. now is the problem that i have 3k gear on it? the spark plugs seem fine and so do the leads. could it be my timing is completely out?

 

any light shed on the matter would be great.

 

cheer nick

 

Have you got fuel squirting into the carby when you pump the accelerator, and spark at the leads, if so,

your timing must be out.

good luck

cheers justin

Posted

Did the dissy get replaced?

It mite be out turn the motor over by hand with the plugs out and check the position of the dissy by the timming mark and when the points open

Posted
Did the dissy get replaced?

It mite be out turn the motor over by hand with the plugs out and check the position of the dissy by the timming mark and when the points open

 

i would have to agree. The distributor on the 4k is usually the cause of firing failures. What I do usually is open the dissy and re-adjust the contact point to 1mm because it keeps slipping. That's what happens when you buy a $7 dissy :wink:

Posted

yeh i swapped over the dizzys, but i was having the issue before i did anyways. and i know that the dizzy can only go in 2 ways and i have to line up the rotor to cylinder 1.

 

because i changed the alts over, could the belt be an issue if its to tight or loose?

Posted

ok so i'm at my wits end, the engine still wont fire. i adjusted the timing by removing the dizzy and following the instructions in the manual, the engine does sound better when it turns over but thats it, is it possible the engine is just f@$ked? the leads and plugs are clean and fine.

Posted
Checked you actually have spark by removing a spark plug, re-fitting into a spark plug lead and earthing on the engine?

 

plus one, or just put it next to a screwdriver or something while cranking, any spark there??

 

Also throw some petty down the carb while cranking if you have spark, that should get it going and then you must have a fuel issue

Posted
Checked you actually have spark by removing a spark plug, re-fitting into a spark plug lead and earthing on the engine?

 

which bit do i want to earth?

 

plus one, or just put it next to a screwdriver or something while cranking, any spark there??

 

Also throw some petty down the carb while cranking if you have spark, that should get it going and then you must have a fuel issue

 

yeah tried the petty down the carb

 

also have you got the firing order round the right way with the leads :hmm:

 

yes there correct haha

Posted

The threaded part of the spark plug needs to be earthed, as this is normally screwed into the head.

 

Just sit the spark plug up on top of the rocker cover (connected to a lead) and you should be able to see the spark while turning the engine over.

Posted
hey all, halfway through the process of putting a 4k in my 20.

 

we have put the 4k in with the 3k starter motor, carby, fuel pump and alternator. the engine is turning over but it wont fire. now is the problem that i have 3k gear on it? the spark plugs seem fine and so do the leads. could it be my timing is completely out?

 

any light shed on the matter would be great.

 

cheer nick

 

 

G`day mate, I`m starting to think that you may have a crook ballast resistor. The white porcelane thing beside the coil. Did you change the coil or are you still running the factory one. They are rated at 8 volt and most aftermarket coils (bosch gt40 ???) are rated at 13.6 so you can wind up with probs there.

Also, if you happenned to put the dizzy in 180 degrees out, try swapping spark leads 1 and 4 and then 2 and 3. That method is not a cure, but the engine should fire with that lead configuration.

After using a bit of petrol down the carby and the engine not firing, you can bet that the plugs will be really wet. It could be a good idea to pull the plugs out and dry them and then wind the engine over for a minute or so with no accellerator to blow any loose juice from the cylinders. For safety, disconnect you coil lead during this process. Check that the plug gaps are around 30 thou or about the width of a hacksaw blade.

Its also worth checking that your contact points are openning correctly. They should also be around 30 thou. Have a close look at the rotor button to see if it has any sign of cracks or burning where you wouldn`t find it. And while you are at it do the same with the dizzy cap.

There are heaps of things that will stop an engine from firing but the things that I have mentioned would be the most common.

Good luck and feel free to ask more questions if need be.

Best wishes, Old Fella.

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