Speed Reduction

bassintime · April 13, 2011, 03:04:47 PM

Was wondering if anyone has run into this problem? Running a 901 CDX with a 2001-200 Optimax.A 25p tempest plus prop-1 plug out. A 8in slidemaster adjustable JP. First couple times I had it out I could pull 67mph-gps at 5500rpm. The next time I shut down and came in I smelled something hot or something burned electrically. Next couple times out I still have great hole shot-good water preasure-can still get max rpm but can only run 54-55mph-gps. Trouble shooting in service manual says-speed reduction see temp sensors. Trouble shooting in sensors says if one is bad you will have 25% power reduction. ? is if you have 25% power loss, why wouldn"t it be rpm & not just speed? There are 3 temp sensors-1 for each bank of cylinders & 1 for air compressor. Book tells me to take ohm reading across the 2 connecter pins at certain engine temps but electrical is not my cup of tea & could not get any reading. Anyone run into this before?

Ron Fogelson · April 14, 2011, 12:05:25 PM

IMHO and having blown two power heads in 14 months it's much cheaper to bring the motor in for service to a place with a good reputation and have it checked.

bassintime · April 14, 2011, 03:46:34 PM

Quote from: Ron Fogelson on April 14, 2011, 12:05:25 PM
IMHO and having blown two power heads in 14 months it's much cheaper to bring the motor in for service to a place with a good reputation and have it checked.

I agree. Its in the shop now. Was just wondering if anyone had this prob before?

bassintime · April 18, 2011, 11:36:40 AM

Quote from: bassintime on April 14, 2011, 03:46:34 PM
I agree. Its in the shop now. Was just wondering if anyone had this prob before?

OK, I got boat back from the shop & talked to mechanic. He told me he could not find anything wrong. He could not find anything that got hot or burned. He said the computer never took a hit on alarms or anything. Charged me 1/2 hr labor & I was on my way. So I was talking to a buddy who"s been running big outboaeds 4 thirty some yrs. He told me to take a look at my prop shaft hub. GEUSSE WHAT ? Hub had 4 cracks in it. 3 hairline cracks 1 1/2in long & 1 gap crack all the way down the side 3in long. I"m surprised I got any MPH at all or the thing didn"t just shatter. Lesson learned here is just because 1 mech. says its all ok & you know something is wrong, don"t stop there. Keep looking & talking to others- we all make mistakes or overlook things. I hope this info might help anyone else who may run into this problem. Now I have another ?. I bought this boat used in Jan. & there was a new spare hub in the glove box. Does everyone carry a spare with them, or since there was a spare one in the boat should I be concerned about a bent prop shaft now? Welcome to the world of high performance outboards. LOL

Ron Fogelson · April 19, 2011, 01:01:24 AM

I keep a spare hub in my boat and used to keep a spare prop as well. Now if I travel I'll bring the prop but don't keep it in the boat any more.

You can see if the shaft is bent by just spinning it, if it's got a good twist to it. Merc has like a 6/100ths tolerance in the shaft if it's 7/100 they say it's caused by impact.

bassintime · April 19, 2011, 02:35:19 PM

Quote from: Ron Fogelson on April 19, 2011, 01:01:24 AM
I keep a spare hub in my boat and used to keep a spare prop as well. Now if I travel I'll bring the prop but don't keep it in the boat any more.

You can see if the shaft is bent by just spinning it, if it's got a good twist to it. Merc has like a 6/100ths tolerance in the shaft if it's 7/100 they say it's caused by impact.

Thanks Ron. I appreciate your input.

Buzbait88 · April 19, 2011, 06:42:51 PM

When I took my boat to get serviced they pulled the prop off and noted how bad the hub looked so I had them replace it. He highly suggested I carry a spare with me. Especially since I'm a tournament angler.

bassintime · April 20, 2011, 02:30:28 PM

Quote from: Buzbait88 on April 19, 2011, 06:42:51 PM
When I took my boat to get serviced they pulled the prop off and noted how bad the hub looked so I had them replace it. He highly suggested I carry a spare with me. Especially since I'm a tournament angler.

Thanks Buzzbait. The day I seen you at big slough is when I noticed the speed reduction,

Buzbait88 · April 22, 2011, 07:51:56 PM

Quote from: bassintime on April 20, 2011, 02:30:28 PM
Thanks Buzzbait. The day I seen you at big slough is when I noticed the speed reduction,

Check your gas also and replace fuel filters. I had a bunch of problems with mine so I took it in to get looked at and he said my hotfoot was all messed up and wasn't opening full throttle. OK I thought so he fixed it. First time out across spring I hit 61.5! Not cool, Started it an hour later and head back across 63.5 WTH. Started it later and headed out again 65 Sweet! By the end of my tournament I was running 66 and change again with full livewells and all of my gear. I had put new gas in it sat morning and it made a world of difference once it started running through the engine