dp retired
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- Joined
- Sep 24, 2013
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- 1
I have a 1976 Johnson 135 hp. I've put it on an astrglass bass boat that had been sitting for many years untouched. I rebuilt the carbs and made sure the wires were good. The motor ran very good for three short outings on the lake. Had good power and idled good. I checked the timing and it was off a little so I backed it in at the launch and set the timing to 4 btdc. It was running smooth, no miss or backfire, but I didn't have time to take it out and run it. Before I took it out I ran up the road to get gas. Put oil in and gas treatment. Took it out and had a very hard time starting it. Finally got it started. Had a lot of smoke and very rough idle. Put it in gear and it had zero power. Would barely move the boat. Took it home and checked all the setting. Everything seemed to be good. With muffs at idle it would sputter and backfire every few seconds. The rpm's would slow down and pick back up. Then it would stop instantly after a backfire. I found a 1975 Evinrude 135 hp and bought it for parts. It had a broken ring in one cylinder. I started replacing parts one at a time and then running it. Figured the chances of two engines having the same problem would be very small. Started with the carbs. Didn't rebuild them but took them apart and cleaned them. No change. Pumped fuel through fuel pump into clear container, no sediment and no water. Replaced everything under the fly wheel including the fly wheel, no change. Replaced the rectifier, no change. Replaced the power pack and had no spark. Switched it back to the original and it ran the same. Replaced the coils with the spark plug wires, no change. Made a spark gap tester. Spark jumped 7/16. Spark was not blue but did jump. Replaced every wire on the engine, no change. Disconnected the wiring harness at the engine and jumped it, no change. Disconnected the fuel hose at the tank and ran it from a fresh one gallon can with oil, no change. Pumped the primer bulb while running, no change. Put original carbs back on. While off looked in to see reeds. As far as I could see they looked good. None missing. Held paper in front of carbs to check for blow back, none. Pulled heads. Cylinders walls and pistons looked real good. Put new head gaskets on, compression test was good on all cylinders, no change. Replaced fuel pump, no change. So, every external part of the engine plus all wiring has been switched with another engine without making any change to it's performance. Except for the power pack. I can't afford to replace that unless I'm positive it would fix it. Do you have any advice on what tests I should run or what I can do to get this engine to run again? Thank you.