How mush speed loss due to weed??

Most surprising. Codes in ECU's are stored when they occur and are manufacturer specific - not decided by the code reader.

I believe Rinda are able to perform certain own tests to check for faults or findings not stored by the ECU by default, but that should be covered in the manual (also to download).

Mind that you need to know the ECU type to get it right.
 
I'd be 99% certain this is a prop and weight/growth on bottom issue.
The problem is that the boat is not getting on the plane. I'd bet it was slow to get there previously too ?
The optimum rev range for your engine is between 4600-5000 rpm. You were not getting that before either.
Come down a couple of inches in pitch at least and she will be a different boat. Many mercruiser dealers would recommend the big 16x16" props for that type of boat and engine set up.
Then give the bottom a scrub next time out.
Allan
 
I'd be 99% certain this is a prop and weight/growth on bottom issue.
The problem is that the boat is not getting on the plane. I'd bet it was slow to get there previously too ?
The optimum rev range for your engine is between 4600-5000 rpm. You were not getting that before either.
Come down a couple of inches in pitch at least and she will be a different boat. Many mercruiser dealers would recommend the big 16x16" props for that type of boat and engine set up.
Then give the bottom a scrub next time out.
Allan

Sorry but you where wrong on all counts....:o
i took it for a second run after anti fouling and there was no difference
took for a third run after resetting all fault codes... no difference

took it for a fourth run after FIXING STUCK TRIM TABS...... went like a missile :o:o:o:o:o:o:o:o

Cant believe that i didn't notice the trim tabs when i antifouled it ..
 
Took mine out sunday for first time in months normal top speed 30 knots with clean bum, at 4500 rpm ish, filthy underneath 10/11 knots 3800rpm and er that was it!
 
Hi
Really glad you solved the problem, but I'm afraid your prop is still wrong, going by the figures posted at the start of the thread.
All the best
 
Took mine out sunday for first time in months normal top speed 30 knots with clean bum, at 4500 rpm ish, filthy underneath 10/11 knots 3800rpm and er that was it!

What boat and engine is that on because on my 19 Foot Fletcher GTS with a 3 ltr Mercruiser I have lost about 3 knots in speed and that is after she has been on a swinging mooring in quite aggressive water in the river Deben for 3 and a bit months

Dennis
 
I recently took delivery of a bayliner 288 with a 5.7 mercruiser mpi magnum with bravo 3 outdrive.
The boat has only done 230 hrs and was imported from Florida around 3 years ago and sat on a dry stack for the best part of the last three years so it's never been antifouled.
on its first shake down run i was able to do approx 30 knots at around 4200 rpm.
Since then it's had a couple of issues such as a sticking thermostat and the gear lube pipe came off so Ive not really run it.

now that these issues have been resolved i took it for another run today and it would only do 3000 rpm wot and approx 15knots
fortunately I had a Bayliner guy handy who checked the engine management system but couldnt firnd any issues as I was convinced that the engine guardian system was active.
He put it down to a build up of green weed on the hull and that the props where over sized (22's)

How much speed would you expect to loose due to a mucky bottom??

Regards

Mark

Me and my dad had the same problem as you on our four winns 248. He was looking at a product to stop algae and barnickles sticking to the hull. We brought an ultrasonic anti fouling product and it's worked so well for us. He didn't take our boat out for 4 years and when we took it out, the was a thin layer of slim you could easily wipe off with your finger. We found out that it made are boat more fuel efficient and it wasn't harming the environment
 
What boat and engine is that on because on my 19 Foot Fletcher GTS with a 3 ltr Mercruiser I have lost about 3 knots in speed and that is after she has been on a swinging mooring in quite aggressive water in the river Deben for 3 and a bit months

Dennis


Fairline Sprint VP 4.3 v6 with SXA drive, antifouled Nov15 and has been used three times since so a total of about 2 hrs running all at 6 knots, so its my own fault!
 
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