Post Number: 1
|Posted on Monday, February 02, 2009 - 08:22 am: ||
I have a P66 fitted in a 6 metre carvel hull, and have experienced the following, and now cannot get it to start or even to fire..
Some time ago we replaced pistons & rings. But the boat was only used infrequently for a couple of years. I used to row across, start it , and run the motor for a few minutes every few weeks when it was not being used.
It was relatively easy to start, 2 turns of the handle and one good quick pull up from the bottom usually did the trick. It ran very smoothly when cold, but once it warmed up it would miss occasionally. I kept thinking it was fuel related, and finally pulled the carby apart and thoroughly cleaned it out, quite a few times. To no avail, the same continued to happen. One day when running the motor, because it had not been used for a while, I found a loose head bolt which would not tighten, I pulled the boat out of the water and brought it home to fit a Helicoil. I reassembled and started the motor very easily at home. The next day I put it in the water. It started, but stopped within a few seconds, then I cranked it by hand for 3 hours until finally it started. At this stage it would only run on about ¾ choke. I motored for about 15 minutes in this fashion to put it in the mooring. Again I dismantled and cleaned the carby, After this it was harder to start, but by tickling the carby it would eventually start and idle ok.
A better mooring came up, so I went to move the boat. I had trouble starting it. When it finally started, the motor ran at much higher revs, I could not slow it down so decided to move to the new mooring (by putting it in and out of gear for short intervals) where I could access it from the jetty, without the need to row over to it each time. I stopped the motor and have never been able to start it again.
I have tried checking out the carby, compression (which was around 75-80) etc and finally decided to pull it apart to find the problem. After taking the head off I found the rings had siezed in the pistons. (probably caused by the high reving). This was about the time Fairweather Marine went into reveivership. I found a source (Motor Medic) in Bairnsdale Victoria Australia who was able to get a set of rings (which could be fitted), within a couple of days. After fitting these and reassembling the motor I found the Magneto was not giving spark. This turned out to be the points needed refacing after having been unused for quite a few months.. The fuel tank has been drained and new fuel mixed at 50 to 1 using SAE30 oil. However it still will not start.
A friend and myself have checked everything we can think of. We have poured fuel direct into the plug holes, drained the crankcase of excessive fuel. All to no avail.
We now find that it appears no fuel is getting up to the firing chamber even though the fuel is readily available in the float chamber and the jets are clear. We removed the carby and held a hand, then later a piece of paper over the inlet aperture whilst cranking the engine and found limited suction. Is this normal? The inlet aperture with the carby removed also seems to be dry, which I would presume should show traces of fuel. Can anyone shed any light on what may be the cause of the problem.
I can be contacted by email on email@example.com
Post Number: 3
|Posted on Monday, February 02, 2009 - 09:34 am: ||
Ken, I make no claim to being an expert on Stuarts but on a P5 I had years ago, I had some of the symptoms you describe. Dismantling showed the crank shaft/crank case seals had failed. Replacement seals did the job with no further failures. I purchased my present P66 last year and took the precaution of renewing the crank case/shaft seals prior to installation in my 27ft. wooden sloop and have had good service since.
|Posted on Monday, February 02, 2009 - 03:55 pm: ||
I would agree with John here.
Post Number: 63
|Posted on Monday, February 02, 2009 - 05:45 pm: ||
Certainly the Crankshaft seals need replacing. Through infrequent starting/stopping and short running, the seals do not get enough heat in them to become pliable and therefore wear out in a short time. The seals are commonly available at all bearing suppliers in Aust. Cannot put my hand on the number at present. See if they have "Double Lip" seals as they give more seal area.
If you have any problems, get in touch with David Stott thru the Wooden Boat Association of Australia, Victorian Div. Dave runs a P66 as well. (probably watching this thread).
Hope you get it sorted.
Dave, On Lake Macquarie.
Post Number: 32
|Posted on Monday, February 02, 2009 - 06:01 pm: ||
Yes Dave I am watching. I have not had my engine apart and seals must still be OK. Crankcase suction will be critical to get fuel flow, and on a twin the seals will be even more important than a single, as each piston counteracts the movement of the other.
David. WBA Vic.
Post Number: 290
|Posted on Tuesday, February 03, 2009 - 06:53 am: ||
I would agree that the seals are the likely cause of your problems.Replace the originals with some synhetic rubber ones ,easly obtainable at any bearing supply, no machining required ,they fit straight in.
remember also the your engine being a twin requires good compression to tranfer induction gas .I know you said you had new rings ,did you deglaze the bore ? The center crankshaft journal is a bronze bush that acts as a rotary valve to tranfer the induction charge between the two cylinders ,rarely wears enough to worry about but if clearance is more than .008 replace it .I have on occasions given these a ''flash '' coat of white metal to get it back to acceptable clearance