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2003 150hp

Y

yroc

New member
can't get to my original post to reply, here's the problem. motor runs fine hooked up to the water hose, but put it in the water under a load hard to cranck and keep at idle, runs fine at high rpm. things I've done; comp. check 105 to 110 (was told this is good for a low comp. motor?) put in carb. kits looks like they needed it sound alittle better, still same problem. Mech. buddy told me to next check the stator, coil, power pack, and regulator. He also said to keep asking you guys questions. how and what order to I check these or should I be doing something else?

Thanks
 
If the ignition checks out look into the reeds. Poor reeds cause the engine to run rich. The condition usually progresses slowly over time. First the engine starts to load up at trolling speeds and runs well until it warms up. When they get worse you should see fuel puddling up in the airbox. If you run the engine without the airbox watch the carbs to see if fuel puddles up in the barrels of the carbs. It might not be all the carbs. If you ever see a tiny droplet of fuel shoot out the front of the carb the reeds are bad. To know for sure you need to remove the intake manifold and the reed cages. Point the reeds at the sun and see if there are any reeds that are slightly hung open. It just takes a hailine crack of sunshine and that reed is bad. You might get away with 2 or 3 on an engine that big but if you can count 5 or 6 they need to be replaced. You can get Boysen reeds made of a fiberglass like material and it would be a performance upgrade you can feel and hear. For that engine they might set you back $180 plus labor, about 2.5 Hrs. typically
 
I did notice #1 carb having fuel puddle in the barrel, cleaned them all up and then saw that #5 carb had some fuel, recleaned it and now all carbs look clean while running. Will check the reeds and report back.
Thanks
 
checked the left side reeds and sure enough the top leaf plate had 1 gap, the middle plate had 2 gaps, and the 3rd had 1 gap. So should I think that the other side is as bad? Will replace all. The question is do I only replace the leaf valves or the whole leaf plate assy.? Is the cost worth the risk, that is just replace parts vs. the whole assy. Another note, When taking the throttle body plate off the intake manifold I notice a small burnt scar on the bottom port between them on the the manifold side, does not look bad. I think when I clean it up it will rub off fine and clean, just wanted to mention that.
Thanks
 
Typically you replace all the reeds. The others could go bad next year if you don't and you would be doing it all over again. You cannot bend them back. It looks like you can but it barely works. I've seen these burnt looking marks too. It should clean off. Discoloration is normal for the most part. To replaace the reeds you take off the thin metal petals and replace them only, not the reed cages or any other part of the manifold. Remove the curved gold plates and the reed petals will fall right off. I like the boysen reeds becuase the thin metal that the reeds are made of do not tolerate shipping and handling well and you sometimes end up with brand new reeds bent up and cracked open just like the old ones. If you go with metal they sell them by the reed plate. You would need to buy 2 plates for each carb. Boysen reeds come in a complete set but go on a little differently. they come with good instructions and even supply Loc-Tite in most cases because you can't tighten the screws too much or they too will hang open. They're usually two stage reeds, they have a hole in the middle of each reed that's covered by another layer of reeds. BRILLIANT! They work great, cost more and look cool. You'll like the way that engine runs with the new reeds. I always replace reeds with Boysen, never stock. Oh yea, the reed cages come off the manifold so you can get to all the screws. Sometimes the bolts are hidden.
 
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