rattle evo top end
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Intermediate
Joined: Jul 2006
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From:
rattle evo top end
Hey guys I thought i had this rattle coming from my 92 evo heritage licked!
but no its back , I changed primary chain guide ,compensator nut, tightend it down to 150 ft lbs and red loctight ,changed lifters, installed new crane adjustable pushrods.also put innew clutch friction platesand steel plates{now i can find neutral!}.
we didput the bike on a lift and run it in 5th gear under load and the rattle seems to come from the top end around the rocker box area.the rattle starts
around 2500 rpm and goes right up the rev range, it will only do it under load and not in neutral,a mechanic told me it could be piston slap, as the bike has
65000 klms on it, isthis possible?Is it worth theeffort of tearing it all down reboring the cylinders,and installing new pistons ?
this rattle noise is driving me nuts ! any info would be great!!!
but no its back , I changed primary chain guide ,compensator nut, tightend it down to 150 ft lbs and red loctight ,changed lifters, installed new crane adjustable pushrods.also put innew clutch friction platesand steel plates{now i can find neutral!}.
we didput the bike on a lift and run it in 5th gear under load and the rattle seems to come from the top end around the rocker box area.the rattle starts
around 2500 rpm and goes right up the rev range, it will only do it under load and not in neutral,a mechanic told me it could be piston slap, as the bike has
65000 klms on it, isthis possible?Is it worth theeffort of tearing it all down reboring the cylinders,and installing new pistons ?
this rattle noise is driving me nuts ! any info would be great!!!
Road Warrior
Joined: Jan 2007
Posts: 1,276
Likes: 8
From: Minneapolis Area, MN
RE: rattle evo top end
Do a compression test and a leakdown test.
While you have the plugs out, try looking through the hole at the cylinder wall (with piston at BDC or so). You may have to use a small light and possibly remove the tank to see better.
If the compression and leakage are in spec and the cylinders look OK, your valves are seating, the rings are good, and it's probably not piston slap.
Maybe it's rocker slop? Could ba a motor mount?
There's not a lot more in the top end to rattle.
While you have the plugs out, try looking through the hole at the cylinder wall (with piston at BDC or so). You may have to use a small light and possibly remove the tank to see better.
If the compression and leakage are in spec and the cylinders look OK, your valves are seating, the rings are good, and it's probably not piston slap.
Maybe it's rocker slop? Could ba a motor mount?
There's not a lot more in the top end to rattle.
Big Kahuna HDF Member
Joined: Mar 2007
Posts: 29,598
Likes: 19
From: Oregon
RE: rattle evo top end
Hi, sorry you're having the problem.
Can you please describe "rattle?" Is it a tinny, buzzing sound, or a knock like a pencil tapping a table, or?? Is is a metallic knock? What can you liken it to?
Could it be an exhaust shield rattle, or is it a knock inside the engine?
Have you used a long piece of wooden dowel or a long socket extension to listen to try to find it? Put it against the engine and against your ear and move it around.
Do you know even which cylinder it is?
If you've been through the primary/clutch area and also suspect the top end, it sounds as if you don't really know where it is.
Can we narrow this down a bit?
JB
Can you please describe "rattle?" Is it a tinny, buzzing sound, or a knock like a pencil tapping a table, or?? Is is a metallic knock? What can you liken it to?
Could it be an exhaust shield rattle, or is it a knock inside the engine?
Have you used a long piece of wooden dowel or a long socket extension to listen to try to find it? Put it against the engine and against your ear and move it around.
Do you know even which cylinder it is?
If you've been through the primary/clutch area and also suspect the top end, it sounds as if you don't really know where it is.
Can we narrow this down a bit?
JB
Advanced
Joined: Dec 2006
Posts: 56
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From:
RE: rattle evo top end
My 93evo has had a rattle for a while but I was going to change base gaskets,lifters, cam, single fire ignition,exhaust so I figured I would likely find to problem anyhow. And yes I did, the intake gasket was brittle and cracked. If you haven't changed it in the last 2-3 yrs do so even if it isn't bad yet. Also, after putting it all back together it still didn't seem right. Come to find out the accelarator pump was toast also. The carb has been working strictly as gravity feed. Bike is running great and the top end rattle is gone. Sure the biggest cause was intake gasket. Hope this helps.
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Intermediate
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RE: rattle evo top end
thanks for the reply guys! i'm in the process of changing the rocker arm shafts and bushes waiting to get the bushes reamed
this tuesday ,have got the tanks off and top rocker covers off as well ,have changed the intake gasket about 6 mnths ago.
the noise sounds like a metallic rattle comes in about 2- 2500 rpm ,like a metal marbel or something ! Ive had lots of people
ride t to see what the farg it is all come up with different opinions, i tried the stethiscope and it sure sounds like its in the
rocker boxes,but a mechanic told me that bottem end noises can transfer from below through the push rods ,the noise is not a knock
ive heard them before,its a mettalic rattle ! im gonna try the rocker arm bushes this week with the new rocker shafts and i will post my findings here guys.
this tuesday ,have got the tanks off and top rocker covers off as well ,have changed the intake gasket about 6 mnths ago.
the noise sounds like a metallic rattle comes in about 2- 2500 rpm ,like a metal marbel or something ! Ive had lots of people
ride t to see what the farg it is all come up with different opinions, i tried the stethiscope and it sure sounds like its in the
rocker boxes,but a mechanic told me that bottem end noises can transfer from below through the push rods ,the noise is not a knock
ive heard them before,its a mettalic rattle ! im gonna try the rocker arm bushes this week with the new rocker shafts and i will post my findings here guys.
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