Thread: head wont come off

Starter motor not jammed in ?

Could be the timing chain has come off and it is jammed against something . Whatever you do ... don't use brute force as you could damage an otherwise good part .. carefully take it apart and the problem will be self evident .

Hi

Ever thought that you could of lost Oil Pressure on it's last run and seized a bearing on to the Crank?
Drop the sump, and undo the con rod bearings, If the pistons move, you can eliminate that from your problem.

Of all the 1600 motors that I have pulled apart the bearings,have been the biggest fault of failure. followed by scored bores.

50LRO

Originally Posted by 50LRO

Hi


Of all the 1600 motors that I have pulled apart the bearings,have been the biggest fault of failure. followed by scored bores.

50LRO

That would the result of a complete lack of essential maintenance . Typically abusive owners revving the crap out it with almost no oil in the sump. Farmers are the very worst of all . Oil ....

All
another idea comes to mind
a frozen clutch and plate and Flywheel
just a thought
cheers
Ian

thanks to all again. got a tool to pull the front off where you turn the motor if you had a cranking handle. took off the bottom of the motor where the fan belt pulley sits off. stripped the chain cover. chain is intact a little loose but does not turn at all. not sure if its meant to or not. photo attached. my father suggested the clutch stuck and when was running noticed the gears would grind to engage sometimes so loosen the clutch pedal and fiddled with this to no avail. im running out of ideas. dad suggests a stuck sticking clutch. only thing left to remove is the bottom sump cover but not sure whether anything would be wrong there either. re fitted the starter motor is ok. overdrive removed from gearbox so no gears to drive. tried rocking the motor front and rear in gear but without overdrive replacement gear no use im guessing. if it is the clutch or clutch plate what should i do then. dont wont to pull box and motor apart yet. any other tests i could do?

If it is effectively out of gear (overdrive removed) then it would need both the gearbox to be seized and the clutch to be stuck to stop it turning. So my guess is it is something in the engine.

You say the timing chain is slightly loos - this means that if there is no movement at all on the crankshaft, it is not the timing camshaft seized.

I would remove the sump. Remove the bigend caps one at a time - if the piston can be removed, replace the cap, but do not tighten it. I would guess you will find one piston that will not move, and will have to be freed. It is possible that all pistons are free, but the shaft still will not move. In this case it would just about have to be a main bearing seized (rather unlikely) and it could be freed by loosening the offending cap. If the thing that is seized is either a bigend or main bearing, you will have to assess the condition of the bearing shell and journal to decide where to go next.

If it is a piston stuck, it will be rings rusted to the cylinder wall, most likely. It can almost certainly be freed bu filling the offending cylinder with penetrating oil and leaving it for a week or two, then encouraging it to move with a block of wood and a hammer from top and bottom alternately. Be careful not to damage either the piston or the crankshaft journal.

Hope this helps

John

Looking at your photo... the whole thing looks dry - no oil anywhere and surface rust on the timing gear. Usually, the timing area is covered with a film of oil .... that could be a clue as to why its stuck .I would spray diesel all over it ..let it soak in , your pulling it right down anyway .

Do as John suggested but be very very carefull if it comes to hitting the pistons . S1 pistons are not cheap ( $125 each , or more ), and do all you can to save them - they have a wedge shape on top and this makes em very difficult to remove if stuck . The gudgeon pin bushes in the con rod ends are soft too , but these aren't so expensive to replace.

Mike