Issue with bike (Won't turn over)

[OhPleaseHelp]

Evening Chaps,

Hopefully not a tl;dr post.. I hope this is the correct section to post this mechanical question in!

I'm at my whits end with my bike with the amount of grief its given me.

It's a 2001 Honda Hornet F2 (20K ish miles). Bought the bike back in July - never noticed damage along the alternator cover so was leaking oil whilst riding it. Only option at that point was to replace the bottom crank case with one I found on eBay from the same year.

After replacing the crankcase, everything seemed OK. But over time, the bike seem to not want to start. You'd press the starter and the solenoid would click as if the battery was flat. The engine would also make a "clunk" sound, like the crank moved a little. I would keep pressing the starter and the bike would then suddenly turn over and start (and fun fine!)

Now, typically with my luck, the bike did not start on MOT day and it has now expired. It won't start at all, rather. The solenoid would just keep clicking. These are the things I've looked at:

• Checked battery - fine. Replaced it anyway and made no difference
• Checked relay/solenoid. Mate brought a replacement to check and used the screwdriver method to force crank - no luck.
• Checked starter motor - Swapped it with another one, same thing. Retested the old one, spun fine.
• Hand crank is very difficult - Even with all but one spark plug removed, the engine is almost impossible to turn over by hand. Blipping the starter moves the crank little by little and then I can turn it over fairly easily - then becomes impossible by hand to turn when I have the TDC marker at the 10/11 O'clock position.

Now I've heard other possibilities such as dropped valve or bent con rod, but when the bike was running, I did not hear any abnormal noises or vibrations, etc coming from the engine. Ran OK riding the [i]speed limit.[/] It is literally the case of turning it off one night and in the morning it never started again.

It seems something inside the engine is preventing it from turning over, but strange that it only had a small battle starting it one day to not starting again! I also checked the cam chain, although seems very tight (very tight actually), I'm not sure what slack it should have and if that could be my reason.

Apologies for the long post but I just cannot figure out what the issue is - It's pretty much bringing me close to tears with the amount of bad luck this bike has given me.

Any suggestions on what to look at would be great

[scarble]

You put the new cover on and immediately problems? I'd hazard a guess some problem with the new cover or the way you fitted it..
Maybe it's rubbing?

[OhPleaseHelp]

That issue never started straight after replacing the crankcase - it started not too long ago. If I'm right, it started after replacing the radiator!

[Rubin215]

Take out all the plugs and see if it turns over.

Could be a float valve in one of the carbs letting by and a cylinder filling with fuel causing a hydraulic lock.
If it is, you will get fuel ejected out of one of the plug holes.

[CAPP0]

Have you cleaned and tightened the battery connections? And then the main power connection wherever it terminates at the starter motor end?

Try putting a jump lead between the battery earth and the engine near the starter in case it's a bad earth somewhere.

[scarble]

So you say with 3 out of 4 plugs removed its hard to turn over, but only for a small range of rotation and then it frees up?
If you take the 4th plug out, what then?
I realise the 4th plug is probably a bit- difficult to get out but if you've tried everything else you gotta try that.
Also how does the starter ground? Does it ground through the engine block? Have you cleaned up the mating surface?
Generally you'll have two little wires to the starter solenoid, one big red one to the starter motor and the motor ground is through the engine block, but sometimes there's a short braided ground strap from motor to engine block.

Edited by scarble on Saturday 17th November 20:29

[jjones]

The compression stroke of the cylinder with the unremoved plug is the reason for hard hand cranking. This doesn't sound like the problem to me. What battery did you get as a replacement?

[mudster]

You say you replaced bottom crankcase OP.

Did you replace top and bottom crankcase halves as A pair? The top case is normally matched to the bottom and if you've mixed them, the crank journals may not be accurately aligned.

[Triaguar]

Try the engine cut out switchgear.