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Anyone know where I can get a free download? I had one a month or so ago on my computer but one day my computer flipped out and I lost it. I gotta put the top end of this 450 together (hopefully today) and I need some info. I've searched and searched this morning, but, I can't find one. Thanks!
 

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Discussion Starter #6
I have the complete PDF manual if you need it
Hey, h2h,So, I got this trx 450 back together. The top end. It didn't have much oil in it and the very top of the cylinder was scored, so I sent it out....blah blah blah, and the camshaft, and lifters and cam bearings were wiped out. So, I wanna be sure that the oil pump is working. I put oil in it and by cranking it over by hand shouldn't I see some oil coming up to the cam, rocker assembly? I took the oil line that goes to the cooler ( the one on the R side) I think that is the supply side, and cranked it a bit and some oil came out, so it seems the pump is working?
 

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It takes several seconds for oil to get from the pump to the top of the engine - the oil goes from the oil; pump to the cooler, from the cooler to the oil filter cavity (check page 5-2) - from the filter through a passage in the cylinder and head to the cam.

Major change from 05 to 06 - the oil cooler was eliminated and the pressure relief valve was relocated from the engine case to the engine cover directly below the oil filter.

Oil gets to the cam through an internal passage in the cylinder and head - as long as you lubed the cam and other parts with assembly lube or a good grease it will be fine for several minutes of running without oil pressure. If you want to check oil pressure without starting the engine, take the spark plug out, remove the crankshaft hole cap (page 4-10) and using an electric drill with an allen bit in the pinion gear retaining bolt, spin the engine clockwise (however fast the drill will turn it) - you should get a somewhat steady flow to the oil filter from the hole at the top of the filter cavity or from the oil cooler line on the left side of the engine.

If the flow seems insufficient, remove the LH engine cover and inspect the pressure relief valve as detailed in section 5. The only reason to suspect a lack of oil flow to the head is if the engine was serviced by a novice mechanic who used gaskets sealers. Other than that, the failure of the pressure relief valve or oil pump will result in reduced flow to that area. Reduced flow is not a problem unless the engine is allowed to idle more than 3 minutes after reaching normal operating temperature. Extended idling is the #1 killer of cams and heads. I've never seen a failed oil pump, but I have seen engine case damage that locked an oil pump causing a sheared oil pump drive shaft. To service the oil pump requires complete engine disassembly.
 

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Discussion Starter #8
It takes several seconds for oil to get from the pump to the top of the engine - the oil goes from the oil; pump to the cooler, from the cooler to the oil filter cavity (check page 5-2) - from the filter through a passage in the cylinder and head to the cam.

Major change from 05 to 06 - the oil cooler was eliminated and the pressure relief valve was relocated from the engine case to the engine cover directly below the oil filter.

Oil gets to the cam through an internal passage in the cylinder and head - as long as you lubed the cam and other parts with assembly lube or a good grease it will be fine for several minutes of running without oil pressure. If you want to check oil pressure without starting the engine, take the spark plug out, remove the crankshaft hole cap (page 4-10) and using an electric drill with an allen bit in the pinion gear retaining bolt, spin the engine clockwise (however fast the drill will turn it) - you should get a somewhat steady flow to the oil filter from the hole at the top of the filter cavity or from the oil cooler line on the left side of the engine.

If the flow seems insufficient, remove the LH engine cover and inspect the pressure relief valve as detailed in section 5. The only reason to suspect a lack of oil flow to the head is if the engine was serviced by a novice mechanic who used gaskets sealers. Other than that, the failure of the pressure relief valve or oil pump will result in reduced flow to that area. Reduced flow is not a problem unless the engine is allowed to idle more than 3 minutes after reaching normal operating temperature. Extended idling is the #1 killer of cams and heads. I've never seen a failed oil pump, but I have seen engine case damage that locked an oil pump causing a sheared oil pump drive shaft. To service the oil pump requires complete engine disassembly.
Okie dokie. Thanks! I might try the drill trick when I'm ready. I'm chasing valve clearances right now and I'll have to wait until Tuesday to exchange some shims. I made 2 trips to the Honda shop yesterday, but, I got the intakes good. Still gotta get the ex valves right. IDK what I did when I picked up new shims. After replacing the cam/ cam holder/rocker arm assembly, the ex valves measured .016. So I did what I thought was the correct math and put in some new shims and it was tough to get a .002 feeler in it. So back to the shop and got 2 thinner shims and still can't get a .002 in it. It's gonna be a guessing game until I get it right I guess. I'm pretty tight with the shop, so they may let me take an assortment of shims and then bring back what I don't use.
 

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Discussion Starter #9
It takes several seconds for oil to get from the pump to the top of the engine - the oil goes from the oil; pump to the cooler, from the cooler to the oil filter cavity (check page 5-2) - from the filter through a passage in the cylinder and head to the cam.

Major change from 05 to 06 - the oil cooler was eliminated and the pressure relief valve was relocated from the engine case to the engine cover directly below the oil filter.

Oil gets to the cam through an internal passage in the cylinder and head - as long as you lubed the cam and other parts with assembly lube or a good grease it will be fine for several minutes of running without oil pressure. If you want to check oil pressure without starting the engine, take the spark plug out, remove the crankshaft hole cap (page 4-10) and using an electric drill with an allen bit in the pinion gear retaining bolt, spin the engine clockwise (however fast the drill will turn it) - you should get a somewhat steady flow to the oil filter from the hole at the top of the filter cavity or from the oil cooler line on the left side of the engine.

If the flow seems insufficient, remove the LH engine cover and inspect the pressure relief valve as detailed in section 5. The only reason to suspect a lack of oil flow to the head is if the engine was serviced by a novice mechanic who used gaskets sealers. Other than that, the failure of the pressure relief valve or oil pump will result in reduced flow to that area. Reduced flow is not a problem unless the engine is allowed to idle more than 3 minutes after reaching normal operating temperature. Extended idling is the #1 killer of cams and heads. I've never seen a failed oil pump, but I have seen engine case damage that locked an oil pump causing a sheared oil pump drive shaft. To service the oil pump requires complete engine disassembly.

Hey, so I fired up the 450 a few nights ago. It has oil up in the cam area and it sounded good. I let it idle for about 10 minutes, then I fired it up again the next night and let it idle for about 5 minutes with a few raps of the throttle. It seems to run really nice. Except the guts have been removed from the stock muffler....ughhh. So today for kicks I checked the compression...I get 60 psi. I did it cold, too. So is it just cuz it's new and not "broken in" yet, or something else? Yes I checked the ring end gaps. LOL. I didn't do anything to the valves as they appeared to be ok. Would the decompression lever adjustment affect the compression? Should I warm it up and check it again? Thanks, dood! :smile2:
 

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I presume you checked compression with the throttle closed? When checking compression always hold the throttle wide open. On a multi cylinder engine with a single carb (min of 3 cylinders) you can check the compression without opening the throttle because there are valves on the other cylinders that will reduce vacuum in the intake manifold. On a V8 engine there is always both intake and exhaust valves open at the same time on more than one cylinder so the compression will be about the same throttle open or closed, but as a matter of correct procedure, the throttle is always held open or the carb removed to eliminate drawing a vacuum on the intake during compression testing.
 

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I presume you checked compression with the throttle closed? When checking compression always hold the throttle wide open. On a multi cylinder engine with a single carb (min of 3 cylinders) you can check the compression without opening the throttle because there are valves on the other cylinders that will reduce vacuum in the intake manifold. On a V8 engine there is always both intake and exhaust valves open at the same time on more than one cylinder so the compression will be about the same throttle open or closed, but as a matter of correct procedure, the throttle is always held open or the carb removed to eliminate drawing a vacuum on the intake during compression testing.
No, I had the throttle wide open. I did start it and let it idle for 5 minutes and checked it again and it came up to 70psi. Double checked the decomp clearance and the ex valve clearances and they're spot on.
 

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I suggest you check your gauge against another - typically the engine will not start with less than 100 PSI and my friends CRF450 has 120 to 150 PSI depending on how close he is to needing to replace the piston and rings (every 30 hours)
 

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I suggest you check your gauge against another - typically the engine will not start with less than 100 PSI and my friends CRF450 has 120 to 150 PSI depending on how close he is to needing to replace the piston and rings (every 30 hours)
Ya, I might do that.
I did, tho call the local Honda shop and talked to the lead mechanic and told him the same that I posted here. He said that 70 -80 sounds about right with the decomp activated. IDK. But, I do know that I took it for a ride and that is crazy fast. Runs perfect, so..... I can't argue with that. :smile2:
 
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