Jump to content

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

Little pulling power off the line

Recommended Posts

So, I'm new to the forum and appreciate some help here.  I recently bought a 2005 Malibu Response LXI.  The boat is in great shape and I've owned it for almost two months.  The boat has about 1000 hrs and the motor has a little over 600 hrs.  The original 340 Monsoon motor was replaced a year ago with a 380 Hammerhead and seems to run great.  The only complaint I have is that out of the hole pulling a skier (heavier, like myself in the 190# range) is that it doesn't seem to have the power.  After that, its awesome .  It doesn't seem to pull me out very quickly like some of the other boats I ski behind. 

When I bought the boat, the guy said that when he changed the motor, he used the old ECI from the 340 monsoon. Could that be the issue or is it simply what I read about the HH and that they don't have the power off the line?  I appreciate the help and love everything else about the boat. 


Link to comment

So the HH was used? Or you put 600 hours on in one season?

What is the basic info--prop, altitude, etc. 

I'd also run compression and leak down tests to check the long block. Easier to test mechanicals than electronics and if there is an internal issue no amount of tuning will fix it.

If it's running so poorly to not pull up a 190lb-er up with ease there is something amiss.

Link to comment

The HH was used.  About 600 hrs when installed and now there is another 80hrs on it since being installed .  Motor actually seems to run well when just out cruising around and tops out at around 44-45 mph.  It has an Acme prop on it and the lake that I primarily use it on is at just under 1000' above sea level.  It doesn't hesitate or skip at all when pulling, it just doesn't have that snap like the others. My friend has a 95 response with an acme prop and it seems to yank you right out, mine is a bit longer and with the 380, I thought that it would have a little more power on the line.  The two other guys that ski with me are a little lighter, but say its a more steady pull vs a quick yank out.  I'm curious if there is an adjustment, fuel issue, or if the ECI needs to be matched to the motor. 

Thanks for the post and patience, I'm not too technical of a person...... 

Link to comment

I would assume that the ecm program needs to be one specific to the hammerhead. Best bet would be to contact indmar tech support and ask if they used different ecm programs.

top end doesn't seem to indicate a prop issue, but what prop are you running?

Link to comment

has the prop ever been reworked?  not are prop repair jobs are equal.

What year HH is in the boat?  The 380 HH was in 2004 and the was based on the 5.7 block.  If memory serves me, they were definitely softer out of the hole than the Monsoon.  I'd concur that a re-flash of the ECM wouldn't hurt.

Finally, comparing the holeshot of a 95 Response to a RLXi is tough as the 95 weighs 400lbs less than the RLXi, is narrower, etc.

Link to comment

I've noticed with our 380HH you have to be a bit ginger with the throttle when pulling someone up. I can pull a 215# slalom rider out with about 2/3 throttle or so. I've never had an issue pulling someone up quickly, and that is with a 23' boat, DD but still weighty.

That said, these engines are not variable cam timing. So when you are getting the big(ger) power up top, you may sacrifice a little down low. But in any case, the torque at lower revs is not going to really be any better than a 340hp model. With these engines, the displacement more dictates torque. Once you get into the higher revs where the bigger cams are dumping in more air, that's where the hp numbers come in.

Link to comment

I have the 07 LXI with the standard LCR 320 HP I run A OJ prop I think ( 13 x 11.5 ) All I can say is we are a bunch of old farts all of us around 200 / 240 LBS. I know the way a skier starts make a ton of difference in the starting pull. One of our group tends to keep his ski nearly vertical this puts an extreme amount of drag on the boat. It also makes him miss many deep water starts as he tends to be pulled over the toe of the ski. If you add a more slanted ski in the water it can reduce a start in half.  With that said I can pull all of us out in less then five seconds.  I will go with all that have brought up the ECU might be needing re flashing! I don't know how the marine industry sets them up but you would not see the two different power plants with the same calibrations in the auto industry.  My LCR will also take my boat in to the 49MPH area with just me in the boat (GPS) Our hulls are slightly different.   



Link to comment

@Coopdog:  One difference between engines is the camshaft, I am not sure what specific cam the Hammerhead came with, the LCR comes with the GM Marine camshaft which has an excellent low end torque profile.  I would certainly think that ignition timing, spark curve and fueling amounts would not be the same for either configuration, so as noted, you probably at a minimum need to update to the Hammerhead calibration.  IIRC the Hammerhead does not have the same level of torque at low engine speeds and comes on later.  Top speed appears to be lower that optimum so that may hold some clues.

Digging a bit deeper, what is the history of the Hammerhead beyond simply # of hours.  Why was this engine available and why pulled from previous hull, what is the health - compression / leak down numbers.

Link to comment

Pulled the bottom fuel line from the pump and found that the screen was pretty well clogged up.  No sense of scale, but it was a hefty pile.  Need to wait until morning to see if it makes a difference.    


The boat is a 2005, that came with the 340 Monsoon.  Original motor was replaced with a 600 hour 380 Hammerhead.  No idea of the motor's history.  Just know that the previous owner put it in a couple years back.  In the process of getting the serial numbers to confirm correct ECM.

Edited by powbmps
Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...