OK to run (lightly) on 5 of 6 cylinders? - Moderated Discussion Areas

  ContinuousWave
  Whaler
  Moderated Discussion Areas
  ContinuousWave: Whaler Repairs/Mods
  OK to run (lightly) on 5 of 6 cylinders?

search | FAQ | profile | register | author help

Author Topic:   OK to run (lightly) on 5 of 6 cylinders?

Kingsteven18 posted 06-06-2012 06:20 PM ET (US)
Hear this out and try to just answer the question please.
I bought a boat with a Yamaha 2 stroke, 6 cylinder, fuel injected, OX66. Lets assume one cylinder has VERY low compression and consider that cylinder useless. If I do not want to rebuild the motor, can I continue to use it as is? My main use will to putt putt from the dock to a close swimming area or some very light 'cruising'. Better for it to have spark or not? Alter it in any way? Thanks for some straight answers please.
Jeff posted 06-06-2012 07:04 PM ET (US)
While there is a whole lot of "wrong" involved with doing it, the short answer is yes. So long as you do not care about what happens to the motor, are willing to throw rational thought into the wind and willing to deal with the hassle of getting stranded and towed home when the motor gives out.
macfam posted 06-06-2012 07:31 PM ET (US)
King,
What horsepower?
If it is a 250, they run on 5 cylinders at idle, drop to 4, until about 1300 rpm, and then go to 6. Your compression test may be invalid if it's a 250 hp.
Teak Oil posted 06-06-2012 10:01 PM ET (US)
I don't see how it would really be that bad, as long as you don't plan on rebuilding this same engine down the road.
The 5 remaining cylinders has to do more work, and will as a result see increased wear and tear. You should DEFINATELY prop down 2 inches of pitch to help those remaining cylinders push the boat. You are probably not going to be doing the crankshaft any favors either running it like that.
The bad cylinder will still get oiled, but the fuel from the injector will go right out the exhaust. You should probably disconnect that injector as long as the cylinder will still be lubricated, not sure how the lubrication system works on an OX66.
DO NOT plan on going far from home, and make sure you have a kicker if the motor starts clunking lol.
tom976 posted 06-07-2012 09:39 AM ET (US)
If you disconnect the injector, its not going to get oiled at all. This particular two cycle motor mixes the oil and gas mix in the high pressure tank and then shoots it into the cylinders with the injectors.
As for running it on 5 of the 6... Motor wont like it, might run real bad. If you dont care about the motor, use it till it dies.
I would wonder WHY the one cylinder was bad. I have a ox66 225 that had one cylinder low on compression. So I took off the head to see what was up. Turns out the seal was bad and steam cleaned the cylinder real nice. Rust was on the inside cylinder wall and as the piston when back and forth lost compression. I removed the corrosion with a special steel wool of sorts (my dad was a machinist for the airlines and gave me something to use)
(5 of the 6 pistons were around 120 psi. The bad one was around 60 - 70)
Anyway, removed the problem, replaced the gaskets and fired it up. Compression went back to where the other cylinders are and all is happy. Its been running ok for the last 4 years.
The OX66's were good motors, it may be worth poking around a bit to see what the problem may be.
BQUICK posted 06-07-2012 02:42 PM ET (US)
I ran one like that for 2 seasons but the extra fuel it was using was killing me. Also, not the best thing for the environment......
gusgus posted 06-07-2012 02:58 PM ET (US)
I have owned cars with 5 of 6 operating and operated them for years. I have had a plug foul on my 2 smokers and run them hours and hours without even a slight problem. No internal damage what so ever. But if internal damage is the cause, then damage doesn't ever get better or stop occurring.
Two smokers oil whether they burn or not. If the engine cylinder in question has a system which is separate of the other cylinders, then knowing the reason the single cylinder is not functioning is important before running it.
Kingsteven18 posted 06-07-2012 06:21 PM ET (US)
The motor is a 1999 200hp. It's on a Cobia Coastal 226 'deck boat' that I bought just to drive within 1/2 mile from my slip to sun and swim on. My options are to use it as is or part the motor out and just put a 9.9 kicker on it. It would just be a pain hooking up new controls, switching from hydr. steering to mech., etc. My 13' Whaler will have four times the hp.
BQUICK posted 06-08-2012 09:44 AM ET (US)
In that case with very little running I would run it and let it serve it's purpose. As I said I ran mine like that for 2 seasons and I cruised for hours at 4000 rpm. It finally broke a ring and was retired.
If you retire it now it would likely be an easier rebuild though.....rather than breaking it and scoring a cylinder wall.
Teak Oil posted 06-08-2012 04:10 PM ET (US)
I agree just run it as is for that amount of distance
Jkcam posted 06-10-2012 06:56 PM ET (US)
It could last for years. Runner.

Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.

Author	Topic: OK to run (lightly) on 5 of 6 cylinders?
Kingsteven18	posted 06-06-2012 06:20 PM ET (US) Hear this out and try to just answer the question please. I bought a boat with a Yamaha 2 stroke, 6 cylinder, fuel injected, OX66. Lets assume one cylinder has VERY low compression and consider that cylinder useless. If I do not want to rebuild the motor, can I continue to use it as is? My main use will to putt putt from the dock to a close swimming area or some very light 'cruising'. Better for it to have spark or not? Alter it in any way? Thanks for some straight answers please.
Jeff	posted 06-06-2012 07:04 PM ET (US) While there is a whole lot of "wrong" involved with doing it, the short answer is yes. So long as you do not care about what happens to the motor, are willing to throw rational thought into the wind and willing to deal with the hassle of getting stranded and towed home when the motor gives out.
macfam	posted 06-06-2012 07:31 PM ET (US) King, What horsepower? If it is a 250, they run on 5 cylinders at idle, drop to 4, until about 1300 rpm, and then go to 6. Your compression test may be invalid if it's a 250 hp.
Teak Oil	posted 06-06-2012 10:01 PM ET (US) I don't see how it would really be that bad, as long as you don't plan on rebuilding this same engine down the road. The 5 remaining cylinders has to do more work, and will as a result see increased wear and tear. You should DEFINATELY prop down 2 inches of pitch to help those remaining cylinders push the boat. You are probably not going to be doing the crankshaft any favors either running it like that. The bad cylinder will still get oiled, but the fuel from the injector will go right out the exhaust. You should probably disconnect that injector as long as the cylinder will still be lubricated, not sure how the lubrication system works on an OX66. DO NOT plan on going far from home, and make sure you have a kicker if the motor starts clunking lol.
tom976	posted 06-07-2012 09:39 AM ET (US) If you disconnect the injector, its not going to get oiled at all. This particular two cycle motor mixes the oil and gas mix in the high pressure tank and then shoots it into the cylinders with the injectors. As for running it on 5 of the 6... Motor wont like it, might run real bad. If you dont care about the motor, use it till it dies. I would wonder WHY the one cylinder was bad. I have a ox66 225 that had one cylinder low on compression. So I took off the head to see what was up. Turns out the seal was bad and steam cleaned the cylinder real nice. Rust was on the inside cylinder wall and as the piston when back and forth lost compression. I removed the corrosion with a special steel wool of sorts (my dad was a machinist for the airlines and gave me something to use) (5 of the 6 pistons were around 120 psi. The bad one was around 60 - 70) Anyway, removed the problem, replaced the gaskets and fired it up. Compression went back to where the other cylinders are and all is happy. Its been running ok for the last 4 years. The OX66's were good motors, it may be worth poking around a bit to see what the problem may be.
BQUICK	posted 06-07-2012 02:42 PM ET (US) I ran one like that for 2 seasons but the extra fuel it was using was killing me. Also, not the best thing for the environment......
gusgus	posted 06-07-2012 02:58 PM ET (US) I have owned cars with 5 of 6 operating and operated them for years. I have had a plug foul on my 2 smokers and run them hours and hours without even a slight problem. No internal damage what so ever. But if internal damage is the cause, then damage doesn't ever get better or stop occurring. Two smokers oil whether they burn or not. If the engine cylinder in question has a system which is separate of the other cylinders, then knowing the reason the single cylinder is not functioning is important before running it.
Kingsteven18	posted 06-07-2012 06:21 PM ET (US) The motor is a 1999 200hp. It's on a Cobia Coastal 226 'deck boat' that I bought just to drive within 1/2 mile from my slip to sun and swim on. My options are to use it as is or part the motor out and just put a 9.9 kicker on it. It would just be a pain hooking up new controls, switching from hydr. steering to mech., etc. My 13' Whaler will have four times the hp.
BQUICK	posted 06-08-2012 09:44 AM ET (US) In that case with very little running I would run it and let it serve it's purpose. As I said I ran mine like that for 2 seasons and I cruised for hours at 4000 rpm. It finally broke a ring and was retired. If you retire it now it would likely be an easier rebuild though.....rather than breaking it and scoring a cylinder wall.
Teak Oil	posted 06-08-2012 04:10 PM ET (US) I agree just run it as is for that amount of distance
Jkcam	posted 06-10-2012 06:56 PM ET (US) It could last for years. Runner.