Bad speed loss

[firefighter7302]

2001 200 Yamaha ox66
Hey guys need some help when i first got my boat used in february me and timmaahh when and ran them and i was turning about 73 to 74 mph now recently it seems as if it gets worse every time i run it week before last it was 67 and then saturday i was able to get 62 then on the way back to the ramp 58mph now this is all tourney loaded livewells full and tanks full with 2 guys the same 2 guys???? RPM is still holding at 5700 no change there all plugs look good no leaning out or fowling???? I'm truly at a loss please HELP!!!!!!

[DOUGMCGEEFTD]

If you getting the same rpms sounds like the prop is going away. I mean the lift has got to be a lot less or something for the rpms to be the same and the speeds 15 mph slower.

[firefighter7302]

yea i dont know i ran it a few weels ago and only got 67 with 2 people loaded but i was running 70 to 71 so i just thought maybe the hot temps lately but i can justify 2 to 3 mph hour maybe to that but 15 to 20 not hardly

[90xpress]

[firefighter7302]

what would cause that to happen????

[Rebel1]

Check your O2 sensor.

[DOUGMCGEEFTD]

well the heat has everybody down on horse power but not near that much. are you running the same prop you ran 72 with now? is the boat still lifting the same? something has changed somewhere. you could have an engine issue but could be a prop or setup issue. whats the setup boat, motor, engine, prop/props, rpms when it ran good with what prop etc.

[firefighter7302]

i did it wasnt bad slight carbon its soaking as we speak but wasn't bad at all

[firefighter7302]

2005 TZX200 Skeeter
200 yamaha ox66
26 tempest
with this prop on test runs when i bought by me and my partner fuel full and livewells open i ran 71 to 72mph @ 5700rpm
now same load same prop 55,57,65mph all @ 5700rpm

[DOUGMCGEEFTD]

as far as the heat with the speed loss you see a RPM loss with it. I could run XKITTY hard to the limiter in 85 degree weather and below now it just barely creeps to it. I dont lose as much as some because i am on the limiter in the cool so i only drop maybe 1-2 mph. I have seen some 3-5 mph drops in the heat but nothing near what you are seeing especially turning the same rpms. If you turning the same prop, on the same boat , the same rpms with the same gear ratio but 15 mph less you have to have some way increased slippage

[Rebel1]

Try another prop and see what happens.

[DOUGMCGEEFTD]

could be a tach not reading right too. But first i would borrow one of tims props and go run it again. be sure to watch the speed and rpms keep track of it and props you run.

[firefighter7302]

yea i guess thats all thats left to do or take it to the shop$$$$$$ so i guess i'll try that sometimes this week or weekend?!!! NOT THRILLED

[BARRY J]

Could it be a pressed in prop hub spinning? It's strange that there is no loss in rpm.

[DLAB]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by BARRY J &raquo;</td></tr><tr><td class="quote">Could it be a pressed in prop hub spinning? It's strange that there is no loss in rpm.</td></tr></table>
+1, thats what i was thinking, Also check your fuel lines!

[dirtdemon]

also check your tilt and trim it may have a short or bad pump and only alow you to get so much lift and stop, mine did that to me a while back rpms stayed reasonalbly close but lost speed and could feel the boat diggin in the water

[JOHN202]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by DOUGMCGEEFTD &raquo;</td></tr><tr><td class="quote">could be a tach not reading right too. But first i would borrow one of tims props and go run it again. be sure to watch the speed and rpms keep track of it and props you run.</td></tr></table>

I agree with Doug,try another prop first. You may find your tach is off.Are you checking your speed by gps ? also climb under your boat and check your pad area,mine was busted and i lost speed but not rpm's.

[LarryP]

Can I chime in here and just say one word?

Yamaha...................KKKKKIIIIDDDDDIIIINNNGGGG G

[JOHN202]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by pijman &raquo;</td></tr><tr><td class="quote">Can I chime in here and just say one word?

Yamaha...................KKKKKIIIIDDDDDIIIINNNGGGG G </td></tr></table>

Ok, now you can go...

[LarryP]

GO where?