Hello everyone. I am new to this forum and was wondering if anyone could help me. Here is the case:
2004 Predator 500. We were on the dunes and all of a sudden my buddy said it started to lose power then just quit, It was then very hard to get it to start after that. Once it did start, I heard a loud knock the engine was making. Not the normal ticking these engines make.
This goes to step 2. When we got it home we did an engine tear down and decided to do an engine refresher. We had the cylinder honed, installed a new piston, wrist pin, piston rings, intake seals, exhaust seals, intake valves, and shimmed the valves to spec in the OEM service manual. Got a compression reading of 100. Upon start up, we primed the oil pump. It started extremely easy. Next, we started to hear a ticking but no serious knocking. After letting it idle for a while, we got anxious and decided to take it for a quick spin. About 1 minute of riding it, it just quit and did not want to start again. Upon tear down we removed the head again....Uh oh... we made a dumb mistake. Somehow we managed to put 4 intake valves in the head and left the exhaust valves out. This explained why we had to shim very high on the exhaust side. The valves smashed into the piston quite a bit. The piston was cracked, exhaust side valves were bent. About the only thing that was good was the intake valves. There was no apparent damage to the head where the exhaust valves seated and somehow the cylinder was not scratched or gouged. It also appeared that timing was not in sync after this happened so we spent even more money all over again.
Step 3. Now total in the motor we have NEW:
Piston
Rings
Wrist Pin
Intake Valves
Exhaust Valves
Intake seals
Exhaust seals
Timing Chain
Timing Chain Tensioner
The valves are now shimmed to OEM specs again. Fresh oil and filter. I reused the head gasket since it was new during the first build. Timing marks are all on per the OEM service manual. Same as it was the first time that is started so easily. Here is the issue:
I am only getting a compression reading of 58. Now it is extremely hard to start. And when it does start, that loud knocking noise is back. Do not even want to keep the engine running when hearing it. That is how bad of a sound. We have done almost a completely new top end. Does anyone have any ideas as to what the noise could be and why compression is now so low? Help please.
2004 Predator 500. We were on the dunes and all of a sudden my buddy said it started to lose power then just quit, It was then very hard to get it to start after that. Once it did start, I heard a loud knock the engine was making. Not the normal ticking these engines make.
This goes to step 2. When we got it home we did an engine tear down and decided to do an engine refresher. We had the cylinder honed, installed a new piston, wrist pin, piston rings, intake seals, exhaust seals, intake valves, and shimmed the valves to spec in the OEM service manual. Got a compression reading of 100. Upon start up, we primed the oil pump. It started extremely easy. Next, we started to hear a ticking but no serious knocking. After letting it idle for a while, we got anxious and decided to take it for a quick spin. About 1 minute of riding it, it just quit and did not want to start again. Upon tear down we removed the head again....Uh oh... we made a dumb mistake. Somehow we managed to put 4 intake valves in the head and left the exhaust valves out. This explained why we had to shim very high on the exhaust side. The valves smashed into the piston quite a bit. The piston was cracked, exhaust side valves were bent. About the only thing that was good was the intake valves. There was no apparent damage to the head where the exhaust valves seated and somehow the cylinder was not scratched or gouged. It also appeared that timing was not in sync after this happened so we spent even more money all over again.
Step 3. Now total in the motor we have NEW:
Piston
Rings
Wrist Pin
Intake Valves
Exhaust Valves
Intake seals
Exhaust seals
Timing Chain
Timing Chain Tensioner
The valves are now shimmed to OEM specs again. Fresh oil and filter. I reused the head gasket since it was new during the first build. Timing marks are all on per the OEM service manual. Same as it was the first time that is started so easily. Here is the issue:
I am only getting a compression reading of 58. Now it is extremely hard to start. And when it does start, that loud knocking noise is back. Do not even want to keep the engine running when hearing it. That is how bad of a sound. We have done almost a completely new top end. Does anyone have any ideas as to what the noise could be and why compression is now so low? Help please.