Top speed on 02 islandia

[alucard2391]

Just curious what other peoples top speed is with the 240 merc with full tank & two adults? I am about 35-40 and 6k rpm

 

[Dr Honda]

I can hit 48 (gps) by myself, top down, no extras on board, and half tank of fuel. I'm pushing up to 6200~6300 rpm.

 

[alucard2391]

I have not tried gps just the old spedo maybe this weekend I will try gps. Thanks for the reply

 

[Dr Honda]

Oh... and if I forget the rear ladder in the water... I can only hit 28. LOL. First time I did that... thought my engine was busted.

But for a more real speed.... I run 35 mph down the river with 8 people, full tank, full water, food/gear for the day and top up. (at about 75% throttle) I can still get to 40 mph with that load.

 

[matthewdandrea]

I was running 50 full tank and 3 adults, 3 kids in my 2000 challenger with the same engine.

 

[AnviL Man]

03 Speedster I'll hit 48-49 on GPS with two people in boat.

 

[njrealtor55]

what rpm is the 240efi supposed to run at? i'm getting around 5200

 

[bobbob911]

Hmm, wonder what I’m doing wrong - I top out at 35 with my ‘04 250 Opti?

 

[Dr Honda]

what rpm is the 240efi supposed to run at? i'm getting around 5200

5900~6000 is a healthy engine. I've tweaked mine, and I'm getting closer to 6300 rpm out of it. 5200 is low. Either your compression is dropping... or one sparkplug isn't firing.

 

[njrealtor55]

5900~6000 is a healthy engine. I've tweaked mine, and I'm getting closer to 6300 rpm out of it. 5200 is low. Either your compression is dropping... or one sparkplug isn't firing.

oh boy - that is a problem. it has been 5200 rpm since i installed the new crawley marine engine last season. good thing i have a brand new snap on compression tester.

please tell us how you got to 6300. impeller re-pitch? case cleanup & porting during your rebuild?

 

[Dr Honda]

oh boy - that is a problem. it has been 5200 rpm since i installed the new crawley marine engine last season. good thing i have a brand new snap on compression tester.

please tell us how you got to 6300. impeller re-pitch? case cleanup & porting during your rebuild?

Let me know what you get for compression. But that 5200 rpm is almost exactly what you get with one plug not firing. (You could have a bad coil pack) Pull your plugs and see what they look like.

When I had my engine apart... I massaged the ports a little. (raised the exhaust ports about 0.010") Cleaned all casting lines out of the case... and took a few thou off my block. (My static compression is 143 psi)

My pump and impeller are stock, but carefully rebuilt. (no repitch)

FYI... the "Hot Outboard" guys will take these same 2.5L Mercs ad push them hard. I've heard 10,000 RPM is not unreasonable.

 

[dblackstone]

05 islandi 250 Opti, 2 people full fuel, full water tank. 43 MPH at 5900 rpm

 

[bobbob911]

Sure enough, my 250 OPTI is maxing out at around 5200 RPM. Maybe I should clean the spark plug heads.

Is it doing any damage to the engine to run it (hard or otherwise) in this state?