135 opti on a Lund Fisherman prop help please!!

[luckydog25]

I have a 2002 Lund Fisherman 1800 with an 02 135 optimax. It came with a 21 pitch aluminum prop. If I try and take off to slow or to fast the alarm goes off (i am assuming over rev) and I have to let it come back down and try it again. I have had it happen with 5 guys with a full gas tank and live wells and with half a tank of gas and just myself and my wife. I get anywhere from 39 to 42 mph now, and am ok with the speed. I just want to be able to drop the hammer and get on plane quick without losing much of my top end. Obviously I am looking for a stainless prop...any suggestions?? I don't have a ton of time to go try out 4 different props as I have a tourney in less than 2 weeks. Any help would be greatly appreciated!!!

[boatfixer]

Can you describe the alarm please? steady, intermittant? What RPM's are you hitting at WOT? Is the motor going into a safe mode? Does it seem to slip and then catch?

[luckydog25]

It is a steady alarm, I am assuming that is safe mode. It will happen either when I am moving a short distance up on half plane or if I am trying to get up on plane to fast or to slow. Doesn't seem to slip than catch...maybe a bit if I gun it to get on plane. WOT it runs at 5200-5300 when trimmed up for max speed. I don't have the smart craft gauges so that is what the lund tac is saying. The alarm has never gone off when up on plane.

[boatfixer]

Seems like it has more to do with the angle of the boat than RPM. Is the oil tank full? Something else that comes to mind is the over heat warning. When a boat is at half plane, there is alot of drag and it just maybe that if the impellor is weak, it may be building just enough heat to trip the temp warning.

When it goes into a safe mode, it will cut half the cylinders out, you would certainly notice that. Any loss in power? Does it seem to happen at any particular RPM?

[luckydog25]

It loses all power. I have left the throttle in place when the alarm sounds and the boat just sets back down until I back it off to idle. It has a new impeller last year. Also it happens in cold water with little running time. The oil tank has 2 gallons in it still. I haven't looked at the tac when trying to get up on plane so not sure what the rpm's are then, but that is the only time the alarm sounds. I have made 10 mile runs and longer going almost WOT this year with no problems...just trying to get up on step.

Thanks for the help!! Any more ideas?? I assumed the prop was the wrong pitch...now maybe something with the motor??

[luckydog25]

Also I do have the motor trimmed all the way down when taking off.

[boatfixer]

Check your owners manual, but I think a steady alarm indicates overheat. If I had it I would verify head temp with a lazer thermometer.

[boatfixer]

Another thing, Does it have a water separating fuel filter that you know of?

[luckydog25]

Not sure if it has a water seperating fuel filter. If it is overheating would it do it while trolling also? I trolled for about 5 hours on Saturday with no alarm sounding.

[PerchJerker]

It also sounds to me like it's overheating. I have an Opti with Smartcraft gauges (so I can see my engine temperature) and it will overheat in 2 situations.....

One is if I'm going 10-12 miles an hour, which is not enough to get my boat on plane --- the motor works hard and the boat plows water. If I cruise at that speed the thermostats do not open up and the overheat alarm eventually goes off. As soon as I slow back to idle, or open it up to get on plane, the motor cools down.

The other is if I'm dragging weeds on my lower unit, as soon as I punch the throttle the overheat alarm goes off. I simply slow down, hit reverse to clean the weeds off, and it's good to go again.

I don't think it's your prop. I think it'd be a good idea to have your impeller and thermostats checked, maybe even your water pump. Good luck.

[PK3]

I agree that with others that it is most likely not a prop issue. This motor does have a filter that separates water/fuel and should be changed in accordance with oweners manual. It would also help to answer your question if you can say which alarm light (gauge has four) is on when this happens. Please keep us posted.

[luckydog25]

There is no light that comes on, just the constant beep. I am going to make an appointment to have the impellor replaced since I fish the mississippi and other shallow sandy waters often, and have them replace the filter and check the thermostat.

I still want to switch to a stainless prop. Others have recommended the tempest plus. Does anyone have a similar boat motor combo with any recommendations?? Model, pitch, ect..

Thanks for the info everyone!! I will have time to get the boat into the shop before I leave next week for a tourney...could easily have saved me a major headache!!

[BoxMN]

Yes, get (once you test it, you will get it, haha!) a Tempest Plus in 19" for that motor on that size/type hull. About the same as a 150. Good luck! We had a 21" tempest for a short while, but too much prop for our 150 and 18' alum hull, the 19" is perfect. The Hi Five will handle great and shoot out of hole like a rocket (the Tempest will too) but Hi-Five has no reverse power. We used 21" Hi5 on ours until we got the Tempest.

[luckydog25]

I have a 23 pitch high five from my last bass boat, I tried it and no go. It came out of the whole fine and did about the same top end, but felt like I didn't have the same control when turning...ect.

19 pitch...good to know. I was thinking 20 or 21, but if it was a bit much for your 150 it will definetly be to much for my 135.

Anyone else??

[PerchJerker]

I've run a tempest and a high 5 on my Opti, but got rid of them both after I ran a Rev 4. Best combination of hole shot, speed, speed and handling with a load, bite in reverse, etc. My guess is a 19 would be plenty of pitch for your rig, possibly even too much pitch, but a prop guy could give you a better answer.

[marine_man]

I agree that I'd start with a 19... it'll be close, given your current RPM's, but I think it would be a good place to start... an 18 might be even better.

The 21 on there now is a tad bit tall if you're only getting 52-5300 RPM's...

marine_man

[PK3]

I currently have a Mercury laser 2 Stainless with a 21P and have a great hole shot and top end speed at around 5700-5800 RPM at WOT. Seems to be working great, unless I am missing something???

[marine_man]

I currently have a Mercury laser 2 Stainless with a 21P and have a great hole shot and top end speed at around 5700-5800 RPM at WOT. Seems to be working great, unless I am missing something???

It depends on your motor... I show top end for his opti is 5500 RPM, which is where you want to run your motor... if he's getting 5200 - 5300, to get to the top end of the spec, you'd have to step down in pitch.

marine_man

[Musky_Madness]

I have a 19P Laser II on a 150 Opti 1850 Crestliner Fishawk that will run 5200 WOT. Prop planes boat well and picked up a few ticks on the spedo as well. Reverse isn't as good however.

[PerchJerker]

I have a 19P Laser II on a 150 Opti 1850 Crestliner Fishawk that will run 5200 WOT. Prop planes boat well and picked up a few ticks on the spedo as well. Reverse isn't as good however.

Your Opti should be 5250 to 5750 at WOT, at 5200 max rpm you could be lugging the motor. It sounds to me like too much prop. I'm in the camp that says you should be running as close as possible to max rpms with a reasonably loaded boat, even if it means you need to drop the pitch or raise the motor one mounting hole, etc.

[BoxMN]

Quote:

Your Opti should be 5250 to 5750 at WOT, at 5200 max rpm you could be lugging the motor. It sounds to me like too much prop. I'm in the camp that says you should be running as close as possible to max rpms with a reasonably loaded boat, even if it means you need to drop the pitch or raise the motor one mounting hole, etc.

Ditto. Lasers are for fast light hulls, IMHO. Tried it on our TP175 and just didn't work. Also tried an older Laser on our 16.5' alum boat with 90 hp and it was just too go fast, but not letting rpms get up there. But everybody has different opinions, which is good fro letting others get more feedback on what will work for them.

Some day would like to try a Revo, but the Tempest just works so well it won't happen for us in some time yet. till we ding it