metriccrescentwrench
Commander
- Joined
- Oct 22, 2007
- Messages
- 2,598
1990 Johnson 200, 1996 carbs.
I've been through h@#$ with this engine, finally got it to where I thought it was ok but still no joy. First off compression is good and even, around 80 on all cylinders. Spark jumps a 1/2" gap on all cylinders. Fuel tank was pristine when I reinstalled it, boat has brand new fuel/water separator and brand new fuel lines.
Previously it was difficult to start and idled very poorly, I finally found hairline cracks in 2 carbs, and others had bad needle valves (looking at online parts diagrams the carbs that were on it look like they're from a '93 or '94 225 - '90 carbs aren't shown with a needle valve). Since I couldn't find exact replacements for those carbs I opted to buy a complete set of freshly rebuilt carbs from a 1996 Johnson 200. I installed them with new gaskets, did a link & sync, set timing, etc. Now the engine starts much easier, usually on the 2nd try. On muffs it idles somewhat rough for a couple of minutes then settles down and idles pretty well (but with an occasional drop in rpm).
I took the boat to the lake yesterday and the engine started right up but had an intermittent severe rpm drop at idle and would often just die. If I was quick with a lot of throttle I could keep it running but not always. It was kind of hard to tell for sure since the boat stayed on the trailer (I didn't want to risk having to dock and then put it back on the trailer with it idling so bad) but it also seemed like there was a bad bog coming off idle.
Is this the elusive "lean sneeze" I've read about?
Can anyone tell me what the initial setting for the idle needle valve is supposed to be for these '96 carbs? And can someone give me a quick rundown of the procedure for adjusting the needle valves, since I've got a 1990 shop manual (with no carb adjustment possible).
thanks
I've been through h@#$ with this engine, finally got it to where I thought it was ok but still no joy. First off compression is good and even, around 80 on all cylinders. Spark jumps a 1/2" gap on all cylinders. Fuel tank was pristine when I reinstalled it, boat has brand new fuel/water separator and brand new fuel lines.
Previously it was difficult to start and idled very poorly, I finally found hairline cracks in 2 carbs, and others had bad needle valves (looking at online parts diagrams the carbs that were on it look like they're from a '93 or '94 225 - '90 carbs aren't shown with a needle valve). Since I couldn't find exact replacements for those carbs I opted to buy a complete set of freshly rebuilt carbs from a 1996 Johnson 200. I installed them with new gaskets, did a link & sync, set timing, etc. Now the engine starts much easier, usually on the 2nd try. On muffs it idles somewhat rough for a couple of minutes then settles down and idles pretty well (but with an occasional drop in rpm).
I took the boat to the lake yesterday and the engine started right up but had an intermittent severe rpm drop at idle and would often just die. If I was quick with a lot of throttle I could keep it running but not always. It was kind of hard to tell for sure since the boat stayed on the trailer (I didn't want to risk having to dock and then put it back on the trailer with it idling so bad) but it also seemed like there was a bad bog coming off idle.
Is this the elusive "lean sneeze" I've read about?
Can anyone tell me what the initial setting for the idle needle valve is supposed to be for these '96 carbs? And can someone give me a quick rundown of the procedure for adjusting the needle valves, since I've got a 1990 shop manual (with no carb adjustment possible).
thanks
