Re: 1987 OMC 1.6L V4 Swap Labor Charge
Thanks guys. As for my toasted motor - Thats what a mechanic told me. I'm not really sure that it is toast. Here is the story -<br /><br />It would start normally & run fine when at wake speed. When going up on plane the rpm for the port motor would lag, as it worked to get up on the step, the starboard motor by over 1000 rpm. At WOT the port motor would max out at 4300 rpm - the stwbd motor at 5400 rpm. After about a half a minute the overheating horn goes off on the port motor. One would imediately think that the motor was getting real hot and binding. But - - <br /><br />Other stuff - <br /><br />1.Water pressure is at 20 pounds at WOT and teltale is strong. Water pump is just over a year old. Mechanic went out with me and with the cover off and the overheating horn blaring away at WOT (4300) and he put his hands on the heads & said that the motor was not hot.<br /><br />2. Compression is 107 lbs on two cylinders, 100 lbs on one and 117 on the other. <br /><br />3. He pulled the heads - The motor was rebuilt before I bought the rig 8 yrs ago - One piston .020 oversized. One piston is rather badly pitted (detonation). The head for that piston also showa detonation and could/should not be re used. It has a couple of small pieces broken off the top edge of the piston by the exhaust ports.<br /><br />4. No major scoring of the walls on any of the cylinders. One cylinder has a "corrosion chunk" out of the wall of the casting about 1/2 the thickness of the wall and the size of 1/2 of a dime. It is right next to the sleve for that cylinder.<br /><br />5. No evidence of heavy carbon build up in any cylinder. All plugs a nice tan color and all look the same. Also good healthy spark to all cylinders. You could easily move each piston from side to side after the heads were off indicating that the rings are free.<br /><br />4. Carbs rebuilt as part of the troubleshooting. They were clean and had no effect on the problem.<br /><br />5. Gas is old ( 80 gal one year old with sta bill). New filters - checked fuel - looks & smells OK and the other engine runs fine.<br /><br />In summary.<br /><br />1. Seems like it is getting hot under load but don't think so. <br /><br />2. I have no clue what caused the detonation.<br /><br />The mechanic recommends that I buy a rebuilt powerhead estimated at around $4,000.00 installed or repower with a new 200 hp Yammy at around $14-15,000.00 (I don't have deep pockets).<br /><br />I am confused at this point both as to what is going on with the motor, what caused it (maybe more than one problem) and what to do. I am looking for alternatives. I know I could give it a stab to overhaul the motor myself but not sure that I would solve the problem as I don't know the cause. I could turn it over to a shop I trust for overhaul. I could buy a remanufactured powerhead. And I'm sure there may be other options.<br /><br />No problems at all with the SeaDrives on either motor.
