1990 CBR is Home
#1
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1990 CBR is Home
finally got my new (old) Bike home no seat back half plastics off etc.
there was metal shavens in the top half of the head. I think if I take the head off I will find the problem. Question, how does the head come off and what should I look for.....to those new to my quest, I bought this bike with a ticking, its on youtube under "Honda Hurricane Motorcycle Noise "
tell me what you think it could be. thanks love these groups.
Mark
there was metal shavens in the top half of the head. I think if I take the head off I will find the problem. Question, how does the head come off and what should I look for.....to those new to my quest, I bought this bike with a ticking, its on youtube under "Honda Hurricane Motorcycle Noise "
tell me what you think it could be. thanks love these groups.
Mark
#2
Only with a fair amount of aggravation and throwing tools across the garage; go back a step, download the manual and really consider if you have both the space and tools that are required for the job.
If you do, please feel free to report back and I'm sure that many of the gnarly old buggers that hang out around here will be more than happy to advise.
Also bear in mind that just because the metal "shavens" are in the head, that doesn't necessarily mean that's where they came from, they may have traveled some way to get there.
Cheers
TK
If you do, please feel free to report back and I'm sure that many of the gnarly old buggers that hang out around here will be more than happy to advise.
Also bear in mind that just because the metal "shavens" are in the head, that doesn't necessarily mean that's where they came from, they may have traveled some way to get there.
Cheers
TK
Last edited by kiwi TK; 04-02-2012 at 07:01 AM.
#3
Join Date: Aug 2008
Location: Republic of Boon Island
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Camshaft is done - find a complete used head assembly with cams
included
Honda Hurricane Motorcycle Noise - YouTube
included
Honda Hurricane Motorcycle Noise - YouTube
#4
Head removal is quite simple, however watch out for snapping exhaust header studs
Also follow the procedure for torqueing down the head bolts in the manual. Removal wont be such an issue as you need a replacement anyway, but they're not that tight and you can esilly strip the threads!
All the work can be done with the engine still in the frame, you just need to loosen/remove the engine mount bolts. Download the Haynes manual if you haven't already done so and read through the procedure in there.
As Sprock has said, you'll need to replace the thing as a full assembly, don't try to just replace the cam shafts.
Let us know how you get on
Also follow the procedure for torqueing down the head bolts in the manual. Removal wont be such an issue as you need a replacement anyway, but they're not that tight and you can esilly strip the threads!
All the work can be done with the engine still in the frame, you just need to loosen/remove the engine mount bolts. Download the Haynes manual if you haven't already done so and read through the procedure in there.
As Sprock has said, you'll need to replace the thing as a full assembly, don't try to just replace the cam shafts.
Let us know how you get on
#5
#6
If you want my honest opinion, it sounds very much like a thrown rod.
The cam rotates at 1/2 the rpm of the engine but the rod knocks at the top and bottom of every stroke. You have a rapid knock. Rod knocks are funny as they sound high up in the head but are generated down below because the sound travels up the connecting rod. What you hear is the trashing of the rod.
When the bearing goes, the is smashed to very fine pieces and carried up to the top of the engine by the cam chain.
To check this out, first pull the side plastic.
You will have to move the radiator forward and remove the exhaust.
From there you can remove the belly pan from the engine.
I believe with the pan removed you can get a hand up in and see if you have play in the rod caps.
If your rod is knocking, you will need to replace the crank and rods.
The cam rotates at 1/2 the rpm of the engine but the rod knocks at the top and bottom of every stroke. You have a rapid knock. Rod knocks are funny as they sound high up in the head but are generated down below because the sound travels up the connecting rod. What you hear is the trashing of the rod.
When the bearing goes, the is smashed to very fine pieces and carried up to the top of the engine by the cam chain.
To check this out, first pull the side plastic.
You will have to move the radiator forward and remove the exhaust.
From there you can remove the belly pan from the engine.
I believe with the pan removed you can get a hand up in and see if you have play in the rod caps.
If your rod is knocking, you will need to replace the crank and rods.
Last edited by TimBucTwo; 04-02-2012 at 10:29 AM.
#7
Well, we all turned out to be a right bunch of Joy Germs didn't we?
How to descend from a bit of a head issue to a major bottom end problem in 5 easy posts.
Mind you, I did make the comment early on that the shavings may not have originated in the head.
I hope we haven't put you off, but there are some intelligent and experienced guys hang out here and you're probably better off starting from the worst case than the best case, at least then you can make an informed decision as to what your next move should be.
Whatever the upshot, and your decision is, I can assure you that there will be plenty of people here willing to offer opinion and advice to help you out.
Cheers
TK
#8
Following logic; Hogsnot had to have removed the valve cover to see the shavings. Hogsnot did not mention catastrophic failure upon viewing cam/valve area. Highly probable not head related. Removing head would revel little.
Hogsnot did mention removing the head to look around. Pipes would have to come off anyway. Good time to pull the belly pan, logically speaking.