K1 Gsxr 1000 Low Compression With New Valves - Suzuki GSX-R Motorcycle Forums Gixxer.com
 
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post #1 of 4 (permalink) Old 04-19-2017, 09:34 PM Thread Starter
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K1 Gsxr 1000 Low Compression With New Valves

I have a 2001 gsxr 1000 that I bought with 6,200 miles and now it currently has 12,236 miles. One evening I was out riding my bike hard and my bike lost power all the sudden (making a weird noise) and wouldn't rev past 6500 rpms. So I got home drained all the oil out of the bike and saw that their was no metal shavings in the oil, so I proceeded to take the bike apart. When I got the motor out of the bike and took the head off I seen were the valves were hitting the piston. After further investigation surprisingly what caused my bike to jump time was a washer that goes in-behind the timing chain guide. The washer was caught on the magnetic pickup coil and finally worked its way loose causing my bike to jump time. So I disassembled the head and noticed that the bike had aftermarket camshafts installed. Luckily I had the receipts to all the work that was done to bike back in 2002. The bike ended up having stage one yoshimura cams along with new valve springs and timing chain. After tearing the head apart and having the head inspected their was no damage to the valve seats or the head. After double checking the head I installed all new oem valves in the cylinder head and reused the valve springs; I also went ahead and bought a new timing chain, timing chain tensor and all new gaskets. Before setting the bike in time, I called yoshimura to make sure that we set the bike in time like OE specifications. After getting the thumbs up that the timing is just like OE specifications we set the bike in time and made sure everything was right. So we ran leak down test and the motor was at 2% on each cylinder which was really good and then we proceeded to check the compression. The compression on each cylinder was only at 130 psi with the engine out of the bike. I know in the factory manual the compression should be around right around 200 psi. I also forgot to mention that the retainer on the intake camshaft spun so I had to have the retainer pressed off and realigned with the cam sprocket. Before taking the engine apart we ran a compression check on each cylinder and the compression was between 182-185 psi. I am looking for opinions why the compression is so low? I am thinking that the timing is off maybe in the cams or maybe the rings are wore? I am looking for any good explanations. I work at a motorcycle shop so I am pretty mechanically inclined, just looking for help because I am stuck. I also have specs on the camshafts if you all need them and I will be posting up pictures. If you need anymore information please ask, I will provide the information you need best to my ability thanks for reading.
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post #2 of 4 (permalink) Old 04-20-2017, 12:16 AM
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Re: K1 Gsxr 1000 Low Compression With New Valves

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Originally Posted by ADavis40 View Post
I have a 2001 gsxr 1000 that I bought with 6,200 miles and now it currently has 12,236 miles. One evening I was out riding my bike hard and my bike lost power all the sudden (making a weird noise) and wouldn't rev past 6500 rpms. So I got home drained all the oil out of the bike and saw that their was no metal shavings in the oil, so I proceeded to take the bike apart. When I got the motor out of the bike and took the head off I seen were the valves were hitting the piston. After further investigation surprisingly what caused my bike to jump time was a washer that goes in-behind the timing chain guide. The washer was caught on the magnetic pickup coil and finally worked its way loose causing my bike to jump time. So I disassembled the head and noticed that the bike had aftermarket camshafts installed. Luckily I had the receipts to all the work that was done to bike back in 2002. The bike ended up having stage one yoshimura cams along with new valve springs and timing chain. After tearing the head apart and having the head inspected their was no damage to the valve seats or the head. After double checking the head I installed all new oem valves in the cylinder head and reused the valve springs; I also went ahead and bought a new timing chain, timing chain tensor and all new gaskets. Before setting the bike in time, I called yoshimura to make sure that we set the bike in time like OE specifications. After getting the thumbs up that the timing is just like OE specifications we set the bike in time and made sure everything was right. So we ran leak down test and the motor was at 2% on each cylinder which was really good and then we proceeded to check the compression. The compression on each cylinder was only at 130 psi with the engine out of the bike. I know in the factory manual the compression should be around right around 200 psi. I also forgot to mention that the retainer on the intake camshaft spun so I had to have the retainer pressed off and realigned with the cam sprocket. Before taking the engine apart we ran a compression check on each cylinder and the compression was between 182-185 psi. I am looking for opinions why the compression is so low? I am thinking that the timing is off maybe in the cams or maybe the rings are wore? I am looking for any good explanations. I work at a motorcycle shop so I am pretty mechanically inclined, just looking for help because I am stuck. I also have specs on the camshafts if you all need them and I will be posting up pictures. If you need anymore information please ask, I will provide the information you need best to my ability thanks for reading.
Was the compression very even on each cylinder?
Or was the compression very different on each cylinder?
If its very different, I'd say cam timing is not correct.
Have Yosh give you the lobe centers for the cam timing and throw a degree wheel on and check it..
On huge cams, valve overlap will show a lower reading. But I tend to doubt your cams are that extreme.
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post #3 of 4 (permalink) Old 04-20-2017, 10:32 AM Thread Starter
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Re: K1 Gsxr 1000 Low Compression With New Valves

The compression before the bike was disassembled was 185 psi across all cylinders and now they are 130 psi across all cylinders. The camshafts were actually stock camshafts sent off to yoshimura and just got regrinded they said. The intake lift is 9.5, open duration is 49 and duration is 248 with 105 lobe center. The only thing it could be is the timing I would think? But for some reason I keep thinking maybe it has a blew ring? I did over fill the bike with oil by accident and all this happened.
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post #4 of 4 (permalink) Old 04-20-2017, 07:53 PM
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Re: K1 Gsxr 1000 Low Compression With New Valves

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Originally Posted by ADavis40 View Post
The compression before the bike was disassembled was 185 psi across all cylinders and now they are 130 psi across all cylinders. The camshafts were actually stock camshafts sent off to yoshimura and just got regrinded they said. The intake lift is 9.5, open duration is 49 and duration is 248 with 105 lobe center. The only thing it could be is the timing I would think? But for some reason I keep thinking maybe it has a blew ring? I did over fill the bike with oil by accident and all this happened.
If it were a ring, it would probably be one maybe two cylinders, not all the way across.
Pull the valve cover, turn engine to TDC #1 cyl and look at your timing marks and relation of cams to each other.
Check it by the book. Also make sure you have the valve adjustment right.
I'm thinking they've probably removes some of the cam's meat off the bottom of the base circle and left lobe height the same.
That usually requires a thicker shim to take up that clearance and get full lift possible.
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