right, the new to me engine is in, plumbing, electrics, oil, propshaft, clutch gearchange all sorted.

BUT it won't start. Turns over well enough, fully charged battery, got fuel in the tank, can hear the pump running. Got spark at the plugs.

What am I missing?

(apart from my MOT in the morning!!)

What engine is it?

zzr1100

3 things for an engine to run

FUEL/AIR mix

Spark

Compression

could the carbs be gummed up?

IS the fuel actually getting to the carbs?

Air leak somewhere?

Knackered pistons/rings?

[Edited on 11/4/10 by Dangle_kt]

Bike engines flood really easily then simply will not start.

If mine does this I take out the plugs, spin the engine over to get rid of excess fuel, then and this is the important one heat the plugs up with a blow torch and put back while still as hot as possible, just blowing off excess fuel is not enough.

You have got the leads the correct way around?

Regards Mark

few things to check

If the loom is a new one are there any resistors now missing

Have you swapped the ecu from old to new

Is your battery above 10v

side stand, clutch switches grounded

Long story short, this is a new ZZR1100 engine, bought to replace my last one.

Loom (modified to close all side stand / clutch switch interlocks), leads, coils, ECU / CDI, all exactly as before. Literally unplugged the old engine, stuck the new one in, re-plugged everything.

Just been out, stuck a new set of plugs in, and it nearly started. Then nothing.

The baby is in bed now, so that's it until the morning.

I'll check compression in the morning, by that time the battery should have taken a charge (it's on an optimate).

If it won't start early doors, I'll try a can of easy start.... before calling the garage and cancelling the MOT test.

Cheers

Mike

has it been sitting for ages? if so could be condensation/crap in your cylinders... eezistarts the way...

Could just be gummed rings, the bang forces the rings against the bores the ring tension just keeps them close so a sniff of easy start to get it running will free stuff off will help.

Other thing to try is a little squirt of oil in each cylinder and winding over a couple of turns before fitting plugs, this will pull up the compression enabling it to start if this is the issue

Regards Mark

Injection?
Make sure you have the fuel flow and return on the correct end of the fuel rail.
If you get it wrong the pressure valve will block any fuel getting through