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1978 kz750 smoke
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21 May 2015 17:12 #673049
by Soxx4u
1978 kz750 smoke was created by Soxx4u
Help please. 78 kz750 blows white smoke out of one cylinder. Compression test showed 90 psi. Where can I find rings
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21 May 2015 18:15 #673063
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21 May 2015 20:04 #673078
by bountyhunter
1979 KZ-750 Twin
Replied by bountyhunter on topic 1978 kz750 smoke
Before you blindly assume it's rings, I recommend you check the valves and valve seals. Also: how many miles on the engine?
1979 KZ-750 Twin
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21 May 2015 20:45 #673086
by Soxx4u
Replied by Soxx4u on topic 1978 kz750 smoke
I checked the valves they are within spec they measure .10 How would I know if my vavle seals are bad and i do not know how many miles are on the motor.
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21 May 2015 21:15 #673091
by SWest
Replied by SWest on topic 1978 kz750 smoke
You can pull the carbs and see oil on the valves, exhaust if you take off the pipes.
Steve
Steve
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21 May 2015 21:16 #673092
by SWest
Replied by SWest on topic 1978 kz750 smoke
Constant smoking does suggest rings.
Steve
Steve
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21 May 2015 21:35 #673094
by Soxx4u
Replied by Soxx4u on topic 1978 kz750 smoke
I have oil in my exhaust pipe and it smoke a lot of white all the time. I only ran the motor for about 2 mins though
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21 May 2015 22:17 #673095
by Tyrell Corp
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
Replied by Tyrell Corp on topic 1978 kz750 smoke
I only ran the motor for about 2 mins though :laugh:
Any oil that you put in your bores during the 'wet' compression test will take some time to clear.
Low compression could be gummed up rings, common on bikes that have been unused for any length of time, often they free themselves just with use.
Any oil that you put in your bores during the 'wet' compression test will take some time to clear.
Low compression could be gummed up rings, common on bikes that have been unused for any length of time, often they free themselves just with use.
1980 Gpz550 D1, 1981 GPz550 D1. 1982 GPz750R1. 1983 z1000R R2. all four aces
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21 May 2015 22:49 - 21 May 2015 22:51 #673096
by bountyhunter
Look at the spark plugs and see if you find any oil residue. That will likely mean a seal has failed.
I would change the oil and run it a while before doing anything.
1979 KZ-750 Twin
Replied by bountyhunter on topic 1978 kz750 smoke
I did not mean valve clearance, I mean valves, seats and seals. The valve stem seals on these twins are notorious for failing and then they leak oil through the seats and build up gunk until they don't seal well.Soxx4u wrote: I checked the valves they are within spec they measure .10 How would I know if my vavle seals are bad and i do not know how many miles are on the motor.
Look at the spark plugs and see if you find any oil residue. That will likely mean a seal has failed.
I would change the oil and run it a while before doing anything.
1979 KZ-750 Twin
Last edit: 21 May 2015 22:51 by bountyhunter.
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22 May 2015 08:38 #673142
by Soxx4u
Replied by Soxx4u on topic 1978 kz750 smoke
Do you think if I use marvel mystery oil that might help
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22 May 2015 11:43 #673167
by SWest
Replied by SWest on topic 1978 kz750 smoke
I've had it do some amazing things. Old Gas crawler 4 cylinder sitting for years. Put some in the cylinders, had to turn it back and forth to free it up, let it sit overnight, rebuilt the carb, it fired right up and bladed our road at Hole In The Hills. Worth a shot.
Steve
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22 May 2015 13:06 #673177
by bountyhunter
I have read people shoot Pb blaster down the spark plug holes to free up stuck rings. Just make sure you change the engine oil before running if you are going to do "soaks" with solvents, cleaners or other chemicals.
1979 KZ-750 Twin
Replied by bountyhunter on topic 1978 kz750 smoke
Soxx4u wrote: Do you think if I use marvel mystery oil that might help
I have read people shoot Pb blaster down the spark plug holes to free up stuck rings. Just make sure you change the engine oil before running if you are going to do "soaks" with solvents, cleaners or other chemicals.
1979 KZ-750 Twin
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