JCurry2885
Seaman Apprentice
- Joined
- Jul 20, 2017
- Messages
- 32
Hello guys,
I bought a 1989 vip fish/ski boat about 2 months ago that came with a 1977 Johnson 70hp outboard. When I first fired the engine it seems to run decent on muffs, but once going to the lake it would fall on its face, and not rev or have any power with throttle. Well after the first lake trip I brought the thing home and began checking everything out. Compression reads 118-120-125 from top to bottom, that was the first thing I checked. I found that I had an intermittent firing issue, and that the stator, and 2 of the 3 coils were out of spec. So I went ahead and purchased a new cdi 6 amp stator, 3 new cdi coils, a new cdi powerpack, as the original looked to be in terrible shape, and a new cdi rectifier since the battery wasn't charging after the new stator install. Also put in 3 new champion spark plugs at this time. Needless to say I now have great spark, and all SEEMS to be well in that department. After all the new parts were installed I still have the same issue. So I pulled the carbs off, and did the best cleaning on them I could. I did NOT remove the welch plugs, and I couldn't eve get the jets out as they were kind of stripped, and I didn't have the proper screw driver. The carbs looked great inside upon inspection, and I sprayed carb cleaner in each hole, and ran a piece of wire in each jet as well. I performed a link/sync to the best of my ability on the carbs, and they all seem to open and close at the same time. A few notes - the motor will idle if you bump up the idle speed a bit, but it does sound like it is missing. Will not low speed idle. Motor wont even try to start hot or cold if you don't choke it, and it is sneezing backfiring like it is running lean. I have also installed a new primer ball, and fuel pump. If you try to free rev the engine it just boggs down a lot, and kinda pops back. The thing does seem to smoke a lot as well when you rev it some. I'm running 50:1 ratio, and the tank just had 18 gallons of 93 octane put in it with new synthetic 2 cycle oil. Carbs still need to be rebuilt? Blown head gasket? I didn't see any evidence of water on the plugs I don't think, other than 2 of them seem almost new after about 10 minutes of run time if that matter.
Thank you!!!
I bought a 1989 vip fish/ski boat about 2 months ago that came with a 1977 Johnson 70hp outboard. When I first fired the engine it seems to run decent on muffs, but once going to the lake it would fall on its face, and not rev or have any power with throttle. Well after the first lake trip I brought the thing home and began checking everything out. Compression reads 118-120-125 from top to bottom, that was the first thing I checked. I found that I had an intermittent firing issue, and that the stator, and 2 of the 3 coils were out of spec. So I went ahead and purchased a new cdi 6 amp stator, 3 new cdi coils, a new cdi powerpack, as the original looked to be in terrible shape, and a new cdi rectifier since the battery wasn't charging after the new stator install. Also put in 3 new champion spark plugs at this time. Needless to say I now have great spark, and all SEEMS to be well in that department. After all the new parts were installed I still have the same issue. So I pulled the carbs off, and did the best cleaning on them I could. I did NOT remove the welch plugs, and I couldn't eve get the jets out as they were kind of stripped, and I didn't have the proper screw driver. The carbs looked great inside upon inspection, and I sprayed carb cleaner in each hole, and ran a piece of wire in each jet as well. I performed a link/sync to the best of my ability on the carbs, and they all seem to open and close at the same time. A few notes - the motor will idle if you bump up the idle speed a bit, but it does sound like it is missing. Will not low speed idle. Motor wont even try to start hot or cold if you don't choke it, and it is sneezing backfiring like it is running lean. I have also installed a new primer ball, and fuel pump. If you try to free rev the engine it just boggs down a lot, and kinda pops back. The thing does seem to smoke a lot as well when you rev it some. I'm running 50:1 ratio, and the tank just had 18 gallons of 93 octane put in it with new synthetic 2 cycle oil. Carbs still need to be rebuilt? Blown head gasket? I didn't see any evidence of water on the plugs I don't think, other than 2 of them seem almost new after about 10 minutes of run time if that matter.
Thank you!!!
