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jill12
10.05.2021 2:01:06

Re: Motor will not accelerate under load.


Vasiliev
07.05.2021 14:59:11

Any ideas maybe electrical or fuel? Any ideas appreciated.


nphyx
22.04.2021 6:07:24

I have a 1978 Mercury 500 50 hp thunderbolt. The motor will start up and idle fine. With ears hooked to the motor using the fast idle or by puting it in gear, it will rev up just fine. With the boat in the water i can put the motor in drive and it will run at idle speeds but as soon as I try to throttle up, the motor will stop running. It has a new trigger and stator. It is missing the mercury switch.


usmanzada2006
04.06.2021 11:53:59

Test compression to ensure all cyls are healthy. [links]


inkubus
10.05.2021 2:01:06

So the issue at the moment is that it won't rev up over 2000 rpm while under load. In neutral, it will spool up no problem. In gear it will run at around 2000 rpm, and occasionally rev up to 3-4000 rpm for a sec, and die back down to 2k. Now the thing is if i keep pushing the choke it will rev up to about 5000 and seem to run somewhat normally. The moment you stop tapping the choke, it goes back to 2k.


esspe
07.05.2021 14:59:11

On with the current issue.. I just bought a 2004 Bentley pontoon. It has a 2004 90hp 2 stroke. The boat has not been used for at least 2 seasons, and according to the past owner, has probably only had about 60 gal of fuel run through it for its whole life..


Waterfox
22.04.2021 6:07:24

Hello, I am new to the forum but have been reading on here for a long time! Have had many boats over the years and encountered many problems.


jarlethaanthonyt
04.06.2021 11:53:59

Due to the fact that when hitting the choke it will rev up, I am under the impression its fuel related. I am wondering if maybe the float valve needs to be changed or thoroughly soaked and cleaned. I am thinking I will take the carbs off again and soak them overnight. [links]


tunixman
02.06.2021 9:45:15

Sounds like the CDI power pack. Had a similar problem on my old 2stroke took a while to diagnose had the same symptoms but i would check compression first to make sure it isnt anything more because a blown cylinder will have the same symptoms. [links]


falkenberg
21.06.2021 18:42:55

2002. last year when ever got over 3500rpm it would alarm and derate costme a fourtune in trying first impellar , then clean out and check water jacket ect , ect , ect ended up looking at new motors but after talking to the marine mech he said it could be the sensor but had never had one fail yet i was ready to buy a new motor so told him to change it any way and it's been good as gold ever since


Arc
04.05.2021 4:51:49

Was it woodies by any chance?


marycaouette
27.04.2021 11:26:07

may seem basic and you prob checked it but quite often this can be weed around the intake. (sounds like the exact symptoms) usually just put in reverse and give it a rev.


djoot
12.06.2021 3:15:20

What type of engine? If it is a modern inboard it could be blocked manifolds (engine cut out due to overheat) [links]


valam
04.05.2021 9:58:42

As time goes on we see fewer and fewer issues with this particular problem. We see more the issue with the hose clamp that attaches it to the bottom of the supercharger. Where the hose clamp can rust and break, allowing the whole throttle body to drop off the bottom of the supercharger.


cre8r
08.06.2021 4:10:06

With the two-piece cowling off, you can access anything on the engine. [links]


meldavies88
24.04.2021 14:39:47

The Verado runs on a timing chain, which makes for a great, maintenance-free valve train. So if these early design blocks jump timing, it could be a serious issue. Unless it only jumps a single tooth. Then the timing chain could be put back on and get the engine back in time without any issues.