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Ok Guys no compression on front cylinder

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Old 11-26-2011 | 07:17 PM
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Ok Guys no compression on front cylinder

OK i installed kreiger mccts timing all checked ok ,put back together and it only ran on rear cylinder. I did a compression test and had 150 psi on the rear and 0 on the front . I pulled the head off and no bent valves but I had a ton of soft carbon on the head and top of piston. I was thinking of pulling front piston ,thought maybe rings are carboned closed or cylinder gas washed not getting a good seal. I am going to send head out to get cleaned and checked . Any other sugeestions would be greatly appreciated . I guess i need to go thru carbs while off the bike .
Old 11-26-2011 | 07:59 PM
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Was there any problem before the CCT change? I know you said it checked out, but if that was the only thing you tinkered with, what else could it be?

Even if it was the rings I'd expect to see SOME compression. Not zero.
Old 11-26-2011 | 08:19 PM
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Sounds as if your cam chain jumped during the change.
Old 11-26-2011 | 08:23 PM
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Must be out of time....I would check and recheck.....
Old 11-26-2011 | 08:32 PM
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180 out?
Old 11-26-2011 | 08:43 PM
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Originally Posted by RWhisen
Sounds as if your cam chain jumped during the change.
+1

Just pull the cam cover and line up the cam marks again.
Old 11-26-2011 | 09:10 PM
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Stuck rings are only going to give you low compression. Hopefully your cam timing is off. I just hope that you didn't bend the valves. They can appear to be seated, but bent. Did you see any signs of piston to valve contact on the top of the piston?
Old 11-26-2011 | 09:27 PM
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Did you use WD40 to test the seal of all of the valves. As mesthhunter said you can't always tell by just a visual check.
Old 11-26-2011 | 10:02 PM
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Originally Posted by mboe794
Was there any problem before the CCT change? I know you said it checked out, but if that was the only thing you tinkered with, what else could it be?

Even if it was the rings I'd expect to see SOME compression. Not zero.
+1.

Check your tools too.

It's very challenging to get zero compression out of an engine.
If you didn't hear any crunchy noises when you started cranking the engine then you shouldn't have done any damage but places to check are valve clearances
Old 11-26-2011 | 10:36 PM
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Originally Posted by thetophatflash
Did you use WD40 to test the seal of all of the valves. As mesthhunter said you can't always tell by just a visual check.

Never tried WD. I've always used brake cleaner. I figured WD would be to thick to get through if you have a bad valve instead of a bent one. If it's not sealing and you check with brake cleaner, it'll leave a wet spot.
Old 11-26-2011 | 10:53 PM
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Once again, it truly seems that just as many VTR's loose there engine due to failed MCCT installation as they do due to failed factory CCT's.

You also should have checked the valve clearances before you removed the head. That would tell you right away if any valves were bent (the clearances would have opened up)

Also it really isn't a good idea to only service one head. The other one will look the same, so you might as well have them both done.

As a FYI the reason for all the carbon build up is the engine is never rev'd.

Run a 4 valve engine at low RPM all the time and that is the result. You need to go and blow the gunk out from time to time. Twist the throttle and let it see some rev's and you won't have the carbon problem.
Old 11-27-2011 | 02:51 AM
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With the front head, if replaced in situ, it's possible to unseat the head gasket as you drop the head into place.

This could explain the problem, but like the others I'm unsure as to why there NO pressure- did you try the gauge back on the rear one, to make sure it sin't a gauge fault?
Old 11-27-2011 | 07:28 AM
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Ok i appreciate all the responses , i have only had the bike about 6 weeks when this happened . i am removing rear cylinder head also appears soft carbon is holdingthe intake valves open slightly. and yes i checked the rear cylinder compression was 150 there.
Old 11-27-2011 | 07:29 AM
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I keep updating the thread as i get along with repairs, thanks james
Old 11-27-2011 | 07:54 AM
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Brake Clean and rubber equal bad things. Valve stem seals are rubber or rubber like material that may deform if Brake Clean gets to thme in seal test.
Old 12-24-2011 | 05:43 PM
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OK guys thanks for all your help . Merry Christmas to all . I just got my superhawk running . It has been an experiance but i now know my bike very well .
Old 12-24-2011 | 08:36 PM
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I had a soft carbon issue from a bike running too rich. Problem was a choke cable out of place and the chokes couldn't close. Get rid of the carbon and all should be fine. Rings can be pretty carboned up as well. Make sure you check the valves for any bends, which is easy to do once out of the head. roll the stem on a flat surface and watch the head of the valve. If you can't pull them apart, check for a leak on the seat with fluid. Any questions, just ask.
Old 12-25-2011 | 12:03 AM
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Originally Posted by Thumper
Brake Clean and rubber equal bad things. Valve stem seals are rubber or rubber like material that may deform if Brake Clean gets to thme in seal test.

I've done it for years, never had a problem with brake cleaner wicking up the valve stem and destroying the seal. YMMV. But brake cleaner is not much of a different solvent than gas. So you'd think gas would destroy them as well. And there is gas in the oil. Most valve guide seals IIRC are made of nitrile (not sure on the spelling). And Nitrile is pretty impervious to most chemicals.
Old 12-25-2011 | 10:43 AM
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Brake clean WILL ruin rubber. It is nothing like gas as it is not petroleum based. It probably won't hurt for doing a simple leak test, but spray an extra o ring with brake cleaner and let it sit for a day, it will be dried out and ready to crack.
Old 12-25-2011 | 10:45 AM
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It's even worse on plastic, it can be used for cleaning but special care needs to be taken.

(my experience is I have been professionally detailing cars for 2 years now and we use brake clean on a daily basis. It's great, but you need to be very careful)
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