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Hi all,
Newbie here (to this forum anyway). Just bought my second Yamaha outboard, a 2005 F8MSHD. I bought this from the guy knowing it was a "fixer", it wouldn't idle at all (below about 1500 rpm). Having cleaned quite a few outboard carbs, I thought this one would be "no sweat". I was a bit off base. The guy didn't tell me he had tried to clean out the carb. There are two "jets" that are quite stuck. They are item #10 and #11 in the diagram down below. I don't completely understand how this thing works but I believe the idle fuel travels through the #10 jet, is that correct? In any case, that one was not only stuck but completely clogged (there was evidence that there was really old fuel in the bowl, something bad anyway). What I ended up doing was taking a No. 60 drill bit (0.040" diameter) through this jet. I'm pretty sure the main nozzle is cleaned well (it's stuck but passes air through well). That did get the motor idling but I did notice that the motor would "bog down" at idle on the water (no matter what the mixture setting) and eventually die. I have a hunch that I drilled it out too much and it's running too rich. Aside from this problem and also not always starting real easily (usually after it's been idling), the motor runs fine. Compression is an even 152 psi. in both cylinders. So, here's my questions:
1. Can someone tell me what the diameter of this jet is supposed to be?
2. Does it seem like that may be the likely culprit of it not idling well?
3. I found a source online for the jet, what's the likilihood that the stuck jet can be drilled & pulled using an easy-out (or tell me an alternative method)?
4. Any other problems that can cause a rich idle (other than mixture adjustment, I've tried the whole range there, pretty much anyways).
Thanks!
Biederboat
Newbie here (to this forum anyway). Just bought my second Yamaha outboard, a 2005 F8MSHD. I bought this from the guy knowing it was a "fixer", it wouldn't idle at all (below about 1500 rpm). Having cleaned quite a few outboard carbs, I thought this one would be "no sweat". I was a bit off base. The guy didn't tell me he had tried to clean out the carb. There are two "jets" that are quite stuck. They are item #10 and #11 in the diagram down below. I don't completely understand how this thing works but I believe the idle fuel travels through the #10 jet, is that correct? In any case, that one was not only stuck but completely clogged (there was evidence that there was really old fuel in the bowl, something bad anyway). What I ended up doing was taking a No. 60 drill bit (0.040" diameter) through this jet. I'm pretty sure the main nozzle is cleaned well (it's stuck but passes air through well). That did get the motor idling but I did notice that the motor would "bog down" at idle on the water (no matter what the mixture setting) and eventually die. I have a hunch that I drilled it out too much and it's running too rich. Aside from this problem and also not always starting real easily (usually after it's been idling), the motor runs fine. Compression is an even 152 psi. in both cylinders. So, here's my questions:
1. Can someone tell me what the diameter of this jet is supposed to be?
2. Does it seem like that may be the likely culprit of it not idling well?
3. I found a source online for the jet, what's the likilihood that the stuck jet can be drilled & pulled using an easy-out (or tell me an alternative method)?
4. Any other problems that can cause a rich idle (other than mixture adjustment, I've tried the whole range there, pretty much anyways).
Thanks!
Biederboat
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