Arizona Hotboater
04-22-2001, 11:36 PM
This is an excerpt from an e-mail I just sent to 10 or so people after lake testing my 200.
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Boat ran fine although I didnt do any top speed runs. I was just there to see if the plugs would color up....they didnt. I had 78 jet's in all but 2 & 5, which had 80's. The plugs wouldnt color much after idling out of the marina, running mid throttle, and then shutting it down clean from a full throttle run with the trim down. I have had a hunch that the jetting is just too rich for 1800' elevation so I took the radical approach. I swapped the 78's for 72's and the 80's to 76's. (I have no 74's) Per my manual, the stock wh22 carbs ran 72's and 74's. After the switch, the boat seemed to have slightly less power/punch and had a bog when the throttle was nailed. Not everytime, about 1/2 the time. Like a lean bog on a holley 4 barrel without an accellerator pump. I checked the plugs again. Same reading. 2 plugs have no color, 2 have a slight hint of reddish-brown, 2 had a more obvious reddish-brown but are still lacking normal coloration. I would think a drastic drop like that would alter the plug readings...nope.
I hit the choke enrichener under full throttle with both sets of jets. with 78's and 80's the rpm fell off when the enrichener was pushed. With 72's and 76's, the rpms fell only when I pushed the enrichener at mid throttle or less. At full throttle there was no drop. This leads me to believe the original jetting was more correct and now the mixture was lean. I ran full throttle, part throttle, and idled in to the marina. I pulled the plugs at home. All were stained black but 5 & 6 had light areas on the insulator. All the others had unifom black coloring from idling in. Also, while under full throttle, we noticed the volt meter pegged past 18 volts. Not everytime but most of the time.
This is really pissing me off. Could there be an electrical problem? I have checked everything with a fluke /DVA. I have done a compression test at least 5 times without grounding the plugs or pulling the kill switch. I didnt know I was supposed to. I did the electrical checks after doing that. It all checks out. Its not mechanical, and its not carbs. Maybe I should just put a new stator, trigger, switchboxes and rectifier on it and see what happens. Oh ya, I could see a couple of the piston domes when I pulled the plugs on the lake. They were black with specs of brown and are not melted from running the 72's / 76's. There is almost no carbon build-up.
This makes no sense. The photos show the plugs I used with the bigger jets. I switched to surface gaps for the smaller jets and the ride home. Note that for each bank there is 1 that is darkest (but still too light), one with a hint of color and one that has no color. I think it was 2 and 3 that were darkest, and the lightest were 5 & 6. 1 and 4 had just a hint of color. There is no water mist in the exhaust chest. I looked with a bend-a-lite. Motor idles, runs and revs fine. Just wont color the plugs and has been down in top speed by about 4-5 mph. Any ideas, guys?
Thanks,
Arizona slow-boater
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Note for those not familiar with my situation: A month ago I put 80's and 82's in the carbs and even held the enrichener in at WOT, and shut it down clean. The plugs didnt color up then either. It cant be lean and after today I know its not too rich.
************************************************************
Boat ran fine although I didnt do any top speed runs. I was just there to see if the plugs would color up....they didnt. I had 78 jet's in all but 2 & 5, which had 80's. The plugs wouldnt color much after idling out of the marina, running mid throttle, and then shutting it down clean from a full throttle run with the trim down. I have had a hunch that the jetting is just too rich for 1800' elevation so I took the radical approach. I swapped the 78's for 72's and the 80's to 76's. (I have no 74's) Per my manual, the stock wh22 carbs ran 72's and 74's. After the switch, the boat seemed to have slightly less power/punch and had a bog when the throttle was nailed. Not everytime, about 1/2 the time. Like a lean bog on a holley 4 barrel without an accellerator pump. I checked the plugs again. Same reading. 2 plugs have no color, 2 have a slight hint of reddish-brown, 2 had a more obvious reddish-brown but are still lacking normal coloration. I would think a drastic drop like that would alter the plug readings...nope.
I hit the choke enrichener under full throttle with both sets of jets. with 78's and 80's the rpm fell off when the enrichener was pushed. With 72's and 76's, the rpms fell only when I pushed the enrichener at mid throttle or less. At full throttle there was no drop. This leads me to believe the original jetting was more correct and now the mixture was lean. I ran full throttle, part throttle, and idled in to the marina. I pulled the plugs at home. All were stained black but 5 & 6 had light areas on the insulator. All the others had unifom black coloring from idling in. Also, while under full throttle, we noticed the volt meter pegged past 18 volts. Not everytime but most of the time.
This is really pissing me off. Could there be an electrical problem? I have checked everything with a fluke /DVA. I have done a compression test at least 5 times without grounding the plugs or pulling the kill switch. I didnt know I was supposed to. I did the electrical checks after doing that. It all checks out. Its not mechanical, and its not carbs. Maybe I should just put a new stator, trigger, switchboxes and rectifier on it and see what happens. Oh ya, I could see a couple of the piston domes when I pulled the plugs on the lake. They were black with specs of brown and are not melted from running the 72's / 76's. There is almost no carbon build-up.
This makes no sense. The photos show the plugs I used with the bigger jets. I switched to surface gaps for the smaller jets and the ride home. Note that for each bank there is 1 that is darkest (but still too light), one with a hint of color and one that has no color. I think it was 2 and 3 that were darkest, and the lightest were 5 & 6. 1 and 4 had just a hint of color. There is no water mist in the exhaust chest. I looked with a bend-a-lite. Motor idles, runs and revs fine. Just wont color the plugs and has been down in top speed by about 4-5 mph. Any ideas, guys?
Thanks,
Arizona slow-boater
************************************************************
Note for those not familiar with my situation: A month ago I put 80's and 82's in the carbs and even held the enrichener in at WOT, and shut it down clean. The plugs didnt color up then either. It cant be lean and after today I know its not too rich.