northerndoc

Hey all- spent the weekend playing with my new to me 2000 35 Lightning w/ 500EFI's. Everything seemed to be functioning properly, but we noticed that across the board, the port engine would be running about 20-30 deg warmer than the starboard. Also noticed more soot on the swim platform around the port motor. They seem to be consuming fuel at about the same rate (within a gallon or two from side to side). Engines have about 220 hours on them. The valve springs were recently done by a qualified merc master mechainc. Fastest speed I could get out of the boat was 79mph gps. Props are 26" hydromotive (stock). Since I am new to offshore boats, I don't have a lot to compare it to, but the report from fountain says the boat should run at least into the low 80's. Couldn't get that out of her this weekend. Was running about 3/4 tank of fuel and two people with a relatively light load. Weather conditions ranged from flat water and no wind to light chop and 10mph winds. Didn't matter upwind or downwind, couldn't break 80. We also noticed the last time we did a run at WOT a "hot" or burning-type smell. Nothing looks out of place in the engine bay and water pressure was pretty close to the same side to side (maybe a little lower port side). I know this is a lot of reading but if anyone could chime in and either ease concerns or give me a direction to look in, it would be appreciated. Thanks!

Kelly O

Is there silent choice on boat ?
If so, is it definitely opening on problem motor ?

blownincome

Pic attached for you Ben

blownincome

Looks like low water circulation to the port manifold and the riser hose and or reversion flap is burning up,,,

northerndoc

Thanks for posting the pic Bob... Will check the operation of the valve on the captains choice tomorrow if I get time. Everything else seems to check out as far as coolant flow. Flushed the oil cooler as you mentioned. See how things go when I try to run it on the trailer.

blownincome

Ben... what were you showing for Water Pressure and engine temps? also can you post a pic of your sea strainer /plumbing set up I think either you have a impeller issue or restriction (flush valve) or something causing low water flow..

northerndoc

I'll take a picture today of the sea strainer setup, but it's pretty straightforward. Didn't see any other connections in line that looked like it might be a flush setup. If I remember correctly, the water pressure was a little bit lower on the port motor than starboard but they were pretty close. At lower RPMS the temps were only about 20-30 deg off (165 starboard, above 180 port). At higher RPMS, especially at the end of the day on Sat, it seemed like we saw temps above 200 on the port motor, with the starboard still around 165. Starting to think that impeller is going or is already shot. How hard is it to replace the impeller?

blownincome

port is easyer to get to than starboard not too hard to do it is the pump houseing and impeller assy on those price is @105 each retail part #46-807151a14

northerndoc

The local marina happened to have one of the pump kits in stock, so I'm gonna run over and get that today, just to have it on hand if its needed. I will take it apart and see how it looks tonight. Mechanic where I bought the boat said both seapumps were replaced last winter when the headwork was done. Is that little ball-valve in the t-stat housing necessary? Have read on here about guys taking them out because they can cause issues. I think since the whole motor was running hot though, it must be deeper than that. What about the circulation pump? I also read about a 45deg fitting in the outdrive where the seapump draws from that can restrict flow... Starting to get confusing, but I guess this is a good way to get familiar with the boat!

blownincome

Start with the known issue points (sea water pump) would be a common one .. when you get it out if the fins look good look in the houseing the back of the impeller might be chewed up causing loss of water pressure