engine info
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valve timing gears
Not familure with the SB8 but unless it is an overhead cam the timing gears are just turning in the cam shaft cover on the front of the engine and covering the camshaft shaft (compleatly) and the crankshaft shaft (shaft goes through the cover to the harmonic balancer and pullies. there may be a fresh water pump mounted over it also.
If you could give us a picture of the front of the engine I could be more specific.
For the record I've never heard of the timing gears needing maintenance.
What are you trying to accomplish?
Not familure with the SB8 but unless it is an overhead cam the timing gears are just turning in the cam shaft cover on the front of the engine and covering the camshaft shaft (compleatly) and the crankshaft shaft (shaft goes through the cover to the harmonic balancer and pullies. there may be a fresh water pump mounted over it also.
If you could give us a picture of the front of the engine I could be more specific.
For the record I've never heard of the timing gears needing maintenance.
What are you trying to accomplish?
I need to see why the valve timing is out of tune by several degrees something went bang and this the result,I have removed everything from
gear case cover but it only comes off 3/4 of an inch cant see whats stopping it.
timing gear cover
OK, I think I understand.
Does the gear case have a split (manufactured joint) in it between the crankshaft part and the camshaft part? In other words is there one part that just covers the camshaft gear and another that would require you to take off the crankshaft pulleys to get it off?
How do you know the valve timing is off? If it where the gears then surely the engine would not run in that condition. The valves would be slamming into the pistons if it is off by more than two teeth on the camshaft. I've never heard of these gears "slipping" without there being massive damage to the block that would allow them to separate. Pretty sure you would notice that with just a casual inspection.
OK, I think I understand.
Does the gear case have a split (manufactured joint) in it between the crankshaft part and the camshaft part? In other words is there one part that just covers the camshaft gear and another that would require you to take off the crankshaft pulleys to get it off?
How do you know the valve timing is off? If it where the gears then surely the engine would not run in that condition. The valves would be slamming into the pistons if it is off by more than two teeth on the camshaft. I've never heard of these gears "slipping" without there being massive damage to the block that would allow them to separate. Pretty sure you would notice that with just a casual inspection.
is this your motor?
http://www.youtube.com/watch?v=PQArZ7GGUIA
Looks like the injector pump and camshaft are organized together under the large cover on the front. The smaller cover to the left of the crank is not the camshaft cover. It does not line up "under" the head so the pushrods would not be able to get to a shaft located under it. It looks like the shaft above and to the left of the crankshaft pulley is the camshaft. As it rotates opposite the crank direction and slower (hard to tell in the video) that would put it in the running for a camshaft. Lines up under the head correctly. you would have to take the crankshaft pulley (harmonic balancer) off to get that cover off however.
Assuming the shaft mentioned is the camshaft it, no doubt, has timing marks on it so you might not need to take the cover off to confirm the timing.
http://www.youtube.com/watch?v=PQArZ7GGUIA
Looks like the injector pump and camshaft are organized together under the large cover on the front. The smaller cover to the left of the crank is not the camshaft cover. It does not line up "under" the head so the pushrods would not be able to get to a shaft located under it. It looks like the shaft above and to the left of the crankshaft pulley is the camshaft. As it rotates opposite the crank direction and slower (hard to tell in the video) that would put it in the running for a camshaft. Lines up under the head correctly. you would have to take the crankshaft pulley (harmonic balancer) off to get that cover off however.
Assuming the shaft mentioned is the camshaft it, no doubt, has timing marks on it so you might not need to take the cover off to confirm the timing.
IMHO you're asking for trouble. If you have to ask this kind of question, you're mostly likely over your head already and don't have a clue what you're trying to fix. If you say, "something went bang", I'd suggest you hire a certified Yanmar technician to check it out. Otherwise, we're going to screw something else up too. Stop digging.
But Ron!!!!
That's how some of us learn.
Ross has it right in his signature block.
I suspect that the "only moves 3/4" problem lies under the smaller cover to the left of the crankshaft on the crankcase cover. One of those pesky fuel pump governors, main crank journals or such nonsense.
As a general rule you have to take the engine apart from the outside inward and not just start unbolting parts. Those smaller exterior parts, fuel lines, injectors..... small stuff, generally has to come of first so that the shaft or leaver/cam that drives them is free to move in directions it only has to move when disassembling/assembling the engine.
Systems check:
Salor27: is it a 4 stroke or 2 stroke engine?
That's how some of us learn.
Ross has it right in his signature block.
I suspect that the "only moves 3/4" problem lies under the smaller cover to the left of the crankshaft on the crankcase cover. One of those pesky fuel pump governors, main crank journals or such nonsense.
As a general rule you have to take the engine apart from the outside inward and not just start unbolting parts. Those smaller exterior parts, fuel lines, injectors..... small stuff, generally has to come of first so that the shaft or leaver/cam that drives them is free to move in directions it only has to move when disassembling/assembling the engine.
Systems check:
Salor27: is it a 4 stroke or 2 stroke engine?
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