2000 75HP Ficht not getting full RPMS

[BoatKid23]

I have a 2001 Starcraft SuperSport 160 with a 75HP Evinrude Ficht. The boat weighs around 850lbs. The W.O.T. should be 5250 RPMs. The most I can get out of this engine is 4200 RPM. The engine has approx 5 hours on it, just picked up the rig last month. The dealer said the boat should run 50-55 mph and the most I can get out of it is around 40-45 mph at 4200 rpm. The engine came with a factory aluminum 19 pitch prop. I know the pitch is high, however the Ficht shoots this boat out of the hole extremely quick. The dealer has updated the EMM software to the latest version which they said should take care of the issue. Went for a ride with the dealer and we still only got 4200 rpms. Is this a rigging issue? Should the engine be mounted up or down more? The engine starts to cavitate at about half trim, sometimes you can get it to full trim without cavitation, but usually only half way. Could this be a prop issue as well? I love the engine and this boat is a rocket since the max HP on the boat is 75 HP. The dealer is not sure why I am not getting the full RPMs. Any help would be greatly appreciated. Thanks

 

[my new fishmaster]

Re: 2000 75HP Ficht not getting full RPMS

Ahoa matte I love Starcraft fishing boats just picked up a 96 170 fishmaster with a 75hp force by mercury. I was in the same boat I went from a 15 pitch prop down to a 11 and I can get my revs up over 5000rpms. My altitude is like 7000 feet which could play a major role in pwr.

 

[DJ]

Re: 2000 75HP Ficht not getting full RPMS

BoatKid23,<br /><br />Are you and the dealer relying upon the tach. in the boat? It may not be right. The engine should be able to tell the dealer through his diagnostic link as to the top rpm acheived. <br /><br />How are you/dealer verifying speed? GPS?<br /><br />A 19" wheel does not sound out of reason for that rig. You're sort of verifying this via your strong holeshot. Going down in pitch may get you your rpm's but I don't see how it will improve speed much-if any.<br /><br />The dealer should work with you on this and make sure everything is reading right.

 

[jegervais]

Re: 2000 75HP Ficht not getting full RPMS

Tell me a little bit more about your motor, is it a tiller handle model or a remote-steer? Has the dealer used the diagnostic software to verify full throttle position sensor (tps) travel? I feel your propping is in the right ball park, it sounds like the tps may only be seeing 75%. It needs to be over 90% when the throttle is full open.<br /><br />-John

 

[BoatKid23]

Re: 2000 75HP Ficht not getting full RPMS

The engine is a 2000 Evinrude FICHT 75HP. As far as I know the only way this particular engine comes is console steering only. The dealer is actually working on the boat right now. I just got off the phone with them and they said that they were going to check the throttle sensor or something like that, they also had made mention that the tach could be off. I could understand if the tach were off, but even if it were off, I should still be able to get at least 50 mph out of this rig. So based upon 40 mph at 4200 rpms the tach must be pretty accurate?!

 

[jegervais]

Re: 2000 75HP Ficht not getting full RPMS

Go here: <br /><br /> http://www.evinrude.com/Dockside/PDF/PE080.pdf <br /><br />and check out the performance data (similar boat). I agree it should turn 5200 rpm's, but expecting 50 mph may be unrealistic. That engine uses a .44 (2.27:1) gear ratio. With a 19P prop @ 5200 rpm's with 0% slip your theoretical speed will be 41/42 mph. Typical slip on a well set up hull is 5% to 10%, which equals 39 to 37 mph. I'm beginning to think your tach is wrong and the engine is attaining full rpm. Ask them to print you a service report off of their diagnostics and take a look at the ecu's rpm profile.<br /><br />-John

 

[DJ]

Re: 2000 75HP Ficht not getting full RPMS

I agree with John. That's why asked about the tach. and speedo. readings. Getting a 75 to push almost any hull past fifty is wishfull thinking.<br /><br />The last aluminum boat I owned (17' Lowe-Fish and Ski) would only do 43 (GPS). And that was with a John. 90 at 5300 rpms. with as light a load as I could make. 38-40 with a full load of fuel and two people.<br /><br />I've always felt, as a general rule, you need at least 125 ponies to hit fifty in a runabout style boat in the 16' to 18' range.

 

[BoatKid23]

Re: 2000 75HP Ficht not getting full RPMS

Thanks for the link I was looking at the specs and that particular boat they tested was longer and weighed approx 200lbs more. That boat also had a 17 pitch prop versus the 19 on mine, however the 17 pitch was a stainless. The boat tested on the link was getting max speed of 39 mph. I hope the tach is right, because if I am only getting 4200 true RPMs at 40-45 mph, the extra 1000 rpms should get me approx another 10 mph?

 

[BoatKid23]

Re: 2000 75HP Ficht not getting full RPMS

I am measuring speed with my GPS..not the speedometer on the boat.

 

[jegervais]

Re: 2000 75HP Ficht not getting full RPMS

I've seen a couple of problems with tiller kits on those engines, that's why I asked if it was a tiller... Obviously not the issue here. Go back and read my prior post - I used a prop calculator program and plugged in the data you provided, with the specs for the motor. I still feel 50 mph is unrealistic, but... you never know. Keep us posted on what your dealer says/does and how things turn out.<br /><br />-John