|
Post by finatic on Oct 21, 2022 15:56:48 GMT -5
My Motors have always at WOT reached 6000 rpms. Ive noticed the past three seasons they have not been able the reach 6000 rpms. Both motors are running beautifully but will only reach 5300 rpms. I never run at WOT but a few times over the year I will run wide open for a very short time just to see maximum rpm. Any thoughts as to where to begin to reach that 6000 rpm number.
|
|
jerryk
Captain
When not online I'm likely on Knot Online
Posts: 597
|
Post by jerryk on Oct 21, 2022 16:41:57 GMT -5
More gear accumulates on boats so weight may be part of it. Bottom paint condition if there is some can have some affect, dings or nicks on the prop can make a big difference in performance especially at top end, and after that I'd look into fuel flow to make sure you aren't starving the motors with clogged filters, pinched hoses or something (although if it is running well I kind of doubt that you have an engine fuel issue, just looking at what might be a cause to eliminate.) When was the last spark plug change? Did the weight onboard increase, including a few extra pounds in fuel or in the captain and crew (sorry to say) since you last checked it out?
|
|
jerryk
Captain
When not online I'm likely on Knot Online
Posts: 597
|
Post by jerryk on Oct 21, 2022 16:43:48 GMT -5
One more thing as I am thinking...an unseen thing might be the weight of water that has migrated into your hull...if you have a wet boat there can be a large added weight there that you didn't know was there.
|
|
|
Post by finatic on Oct 21, 2022 17:15:32 GMT -5
Today I only had 25 gallons of fuel by myself. The boat was very lite all gear is home for the season. Interesting thought jerryk about a wet hull how do you check that. I haven't changed spark plugs in about 400 hrs In my opinion that don't mean chit but planning to change over the winter. My other thought is maybe props could be slipping they do have 1250 hrs on them how do you check them. I did however put a few pounds on. Lol
|
|
jerryk
Captain
When not online I'm likely on Knot Online
Posts: 597
|
Post by jerryk on Oct 21, 2022 17:56:34 GMT -5
Prop spin would show as high RPM with low boat movement, kind of like spinning your tires in snow. At lower RPM you don't spin so at near idle speed all seems normal but if you rev high but don't get on plane I would suspect prop spin. Not thinking you have that but with twins maybe one side is slipping a bit and slowing you down. Not my top guess however.
Spark plugs would be a likely spot to look, and with 400 hrs they need a swap anyway. Good winter project, if you fog the engine for storage wait until you restart in the spring and burn off the fogging oil, then install fresh plugs.
Water in the hull is found with a moisture meter and you may be able to detect it with a plastic hammer tapping in various places in the hull...the sound in a wet section of the hull is decidedly different than in dry sections.
|
|
|
Post by fishnfool on Oct 21, 2022 18:31:56 GMT -5
You don't own a Grady Wet do you?!
|
|
|
Post by fishnfool on Oct 21, 2022 18:33:26 GMT -5
I'd check/replace spark plugs, then clean injectors. Injectors tend to be the biggest culprit of not hitting previously achieved RPMs.
|
|
|
Post by finatic on Oct 21, 2022 19:49:14 GMT -5
I'd check/replace spark plugs, then clean injectors. Injectors tend to be the biggest culprit of not hitting previously achieved RPMs. WI'll do thanks. Starting to look like the end of the year project list is growing .
|
|
|
Post by abouttime2fish on Oct 23, 2022 8:55:21 GMT -5
|
|
|
Post by finatic on Oct 23, 2022 11:53:39 GMT -5
|
|
|
Post by jski59 on Oct 24, 2022 8:49:12 GMT -5
I agree regarding the injectors and trapped water. I remember when the forward bilge pump on my old 23 died, I had quite a bit of water trapped towards the bow.
|
|
|
Post by finatic on Oct 24, 2022 15:54:05 GMT -5
I agree regarding the injectors and trapped water. I remember when the forward bilge pump on my old 23 died, I had quite a bit of water trapped towards the bow. Injectors yes Water in the bilge no I'm sure it's empty. I'M aware that water can gather forward just the way the boat sits, Three of us sitting in the bow front pump turned on. Then running out with bow up no water in the stern. When I pull the boat this week while sitting on the ramp I'll pull the plug my guess is very little water.
|
|