Rough running after engine upgrades.
Grand HDF Member
Joined: May 2014
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From: florida
The hot and cold oil pressure tests will confirm whether or not the oil pump is maintaing pressure to the engine(lifters) after temp is reached. If the pressure drops below spec warmed up, not good lifter action, but there again, there will usually be lifter clatter noise. If the pressure stays up and good, then the solid style lifter adjustment described above might confirm a lifter only isssue.
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Last edited by marcodarq; May 6, 2018 at 10:12 AM.
Seasoned HDF Member
Joined: Dec 2005
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From: poway
The hot and cold oil pressure tests will confirm whether or not the oil pump is maintaing pressure to the engine(lifters) after temp is reached. If the pressure drops below spec warmed up, not good lifter action, but there again, there will usually be lifter clatter noise. If the pressure stays up and good, then the solid style lifter adjustment described above might confirm a lifter only isssue.
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Outstanding HDF Member
Joined: Feb 2015
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From: Arkansas
You wouldn't get the full fuel/air mixture into the chamber either as the valve wouldn't fully open or stay open long enough to get the full mixtur, additionally the exhaust wouldn't open early enough on the cam cycle and the valve wouldn't open all the way as well.
Seasoned HDF Member
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From: poway
At that point you are going to hear the valve train.. If the motor is quiet, you don't have that issue.. Opening and closing ramps on these motor cams are around 0.010 or if you want 0.016 at the valve.
Grand HDF Member
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From: florida
That is why the hot and cold pressure test is important,,,if you KNOW, that when fully up to temp the pressure is good, then you can start to define a lifter issue, since is has to have a predetermined pressure in order to function as it should. This would take the guess work out of the equation about the oil pump, pump o ring, cam plate and pressure releif valve. If the pressure is in spec and the lifter is collapsing, you will know it is a lifter issue or a valvevspring that has too much seat pressure applied.
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Last edited by marcodarq; May 6, 2018 at 11:40 PM.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,962
Likes: 8,056
From: poway
That is why the hot and cold pressure test is important,,,if you KNOW, that when fully up to temp the pressure is good, then you can start to define a lifter issue, since is has to have a predetermined pressure in order to function as it should. This would take the guess work out of the equation about the oil pump, pump o ring, cam plate and pressure releif valve. If the pressure is in spec and the lifter is collapsing, you will know it is a lifter issue or a valvevspring that has too much seat pressure applied.
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Could you explain how what does what.. Sorry but I guess I'm missing what's going on.. How about some pressures as an example.. For me, I typically see say 195 psi cold and 205 hot on a good running motor. How would that change?
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,962
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From: poway
That does a lot.. It doesn't explain why the engine would run poorly if it the valve were quiet.
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Grand HDF Member
Joined: May 2014
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From: florida
Way back inthe begging of this thread i said that he needs to tune the bike. I still think that is his issue. I just said he needed to confirm his compression and leak down tests. Most of the rest of what i've put up has been in response to everyone's other postings. If his oil pressure and compression is good, i thnk his problem is tune/ electrical issues.
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