Post Number: 1013
|Posted on Saturday, January 08, 2005 - 12:24 pm: ||
This was sent to me by Ron at firstname.lastname@example.org .
I have responded to him that he should post any additional comment below and look for responses here. Thanks.
hello thanks for an excellent site can anyone give me some advice on a stuart p5 m.
i stripped the engine as it had been under water , it was cleaned out and was also removed from its boat a1935 20 ft wooden sailing craft,all that seemed worn were the bearings which i replaced the oil seals were fine,the engine would not run but i noticed the crankcases were leaking,this was put right on the rebuild,the engine ran ok on the bench it was a bit lumpy on low revs but run fine otherwise i found the timing odd it sparked just after tdc but i was told this was correct it has the wipac series a mag.
i helped in fitting the engine in my friends boat and it started ok but under load the engine backfires thro the carb this would suggest the timing is wrong ,your site says the timing is 2inches btdc ,is this as the click of the mag is heard do i have to change the position of thecog on the timing chain or is there another way also the exhaust is made up with 18mm copper piping is this two small ? also what is the position of the knelled cylinder on the air intake? will it change the fuel mixture if turned?
many thanks ron
Post Number: 226
|Posted on Saturday, January 08, 2005 - 05:55 pm: ||
Your Wico magneto sounds like it is the impulse type . They are a bit tricky to time. I have only Lucas on my engines. However somewhere there is a site on the Wico impulse magneto,some one will post it i am sure.
Your 18mm diam exhaust is to restrictive,it is probably coked up as no doubt is the silencer. See if you can clean them out ...a caustic bath will do it.Also think about increasing the size, 1 inch would be preferable.
The knurled screw fitting on the carb is the air control. For average running it should be screwed out about 1/4 inch. This could be the cause of the spitting back [ screwed out too far resulting in to lean air /fuel mix...too much air].
You replaced the main bearings ....how were the big end needle bearings?
Post Number: 129
|Posted on Monday, January 10, 2005 - 05:39 am: ||
The timing procedure is the same for impulse or non-impulse magnetos. On the engine flywheel is a "TDC" mark and another "M" mark about 1.5 inches before TDC. Slacken the magneto sprocket/drive cog (on engine) by loosening the set screw/bolt and loosening the cog so that it will move when you adjust the points in the magneto. Refit teh magneto and remove its bakeite cover to get access to the points. Move "M" on the flywheel to TDC position. Turn the magneto spindle until the contacts are just opening (use the ubiquitous piece of cigarette paper if you "roll your own"). Then remove the magneto and fix magneto sprocket with the set screw/bolt.
NOTE: Impulse magnetos and non-impulse magnetos have a different lag angle with the impulse coupling delivering a retarded spark for starting with the spark advancing as the engine gathers speed, finally cutting out at about 200rpm. The endplate in the impulse coupling on the magneto is adjusted to alter the angle.