Moisture remover causes loss of rpm?

[mhannon]

Hi all, just got my 99 E21 last month, love it.  Ran around the lake great on her maiden voyage with the 13x13 prop - 48 mph (gps) at 6000 rpm.  The boat had sat unused for 18 months with the previous owner, so I bought a bottle of fuel system moisture remover.  Misread the bottle, thought it said "treats 25.0 gallons", really said "treats 250 gallons"  and mixed it with a full tank of 87 octane fuel (my other mistake).  Ever since, 4500 rpm's max and only 38 mph.  I burned off 3/4 of that tank of fuel and tried topping off with 93 octane, same deal.  Any thoughts? Have I not given the new fuel enough time to circulate through the system?  Thanks for any help.

[Ktown]

I've learned in my short time reading posts that bad fuel can cause problems with the spark plugs.  You may want to start by relplacing the plugs!  It's seems to be the cheapest fix and takes one part out of the equation.  Those will run about 6.60 - 11.00 dollars each, depending whether or not you replace with Denso's or NGK. (just priced them for my boat).  As for the moisture remover, I am not sure how that will effect your boat, but I'm sure someone else here can speak to that.  Good Luck!

[westtx]

Drain the tank, change the plugs, change the fuel filter, turn the battery switch off, disconnect the battery, let it sit overnight (just to make sure the computer resets), and you should be fine. For a quick fix, try recycling the battery on/off switch.

Since the engines run a 10.5:/1 compression ratio, the computer will back the the timing wayyy back on 87 octane. Also, since moisture remover is mostly alcohol, there is a chance that it scrubbed your tank and fuel lines and released some gunk that could be causing problems.

[mhannon]

Thanks, guys.  I'll be trying the battery cycle and spark plug fixes this weekend.  Just did the fuel filter before this whole deal, boat has less than 100 hours, do you think I could have that much crud in the system?

Another question, my trans seems somewhat noisy.  I really don't have any reference for how loud it should be when I engage forward gear, but other passengers have noticed enough to comment  about it.  Am I being too sensitive to a normal noise or do you think this is something I could diagnose?

[lesman01]

tough to say about the transmission, but the lexus motor is so much quieter than others it's much easier to hear the transmission. In "other" boats, the engine would drown out the tranny noise..

[Rambling Wreck]

I am with you on the tranny noise. However, after reading all of the posts on the subject, I came to the conclusion that it is normal.

[mhannon]

Have any of you noticed if the synthetic trans fluid makes any diff in terms of noise in the trans?  Or other oils/additives (Lucas,etc.) that would be helpful but not counter to long term reliability?

You're spot on about the engine - purrs like a kitty.

[Rambling Wreck]

I used synthetic this year - no difference.

[mhannon]

New plugs did the trick, guys.  Boat runs beautifully now,  got my 6k rpm's and 49 mph back.  Thanks again for the help.

[westtx]

Nice to see an "easy" fix. 49 is smokin for any direct drive!

[mhannon]

Also noticed that the trans noise is considerably less noticeable since the driveline load is more even on the smoother running engine at idle - considerably better. 

I have also seen several people mention that they get the low oil pressure warning beep frequently at idle.  I had this problem as well (very annoying) but it is now gone, oil pressure is in the right region for idle (doesn't fluctuate so much) and wot conditions.

Back to the lake!

[ScarabEpic22]

Nice, 6K and 49mph!!  I think I need to check my throttle cable, I max out at 5600 and probably 45-46ish (both speedos need to be cleared and no GPS onboard).