97 challenger 1800 issues

[James Berres]

Alright I took the boat out the other day after a local shop cleared it for sea trials lol. I left the boat ramp which seemed good. All of a sudden I had both throttles open and I had a max speed of 10mph and rpms where at 3500 rpm. They werent bouncing like it was hitting the rev limiter just seemed to not go past it. I opened the engine comoartment and there was exhaust smoke in it. I found a hose which connects the exhaust to I think a mufflera big black cylinder that is in the rear at the top. Sorry about the great terms im using I am gonna upgrade my membership tomorrow soni can get the manuals. So my question is would an exhaust leak cause this? Any help would be greatful. I am fed up with this local shop giving me the run around on my boat and am gonna dive in and try to fix it myself with hopefully alot of help from you guys.

 

[USAF_Pride]

There is a rev limiter and it is controlled by a switch connected to your Forward/Reverse lever. The switch is probably either stuck or broke. Carefully remove the throttle control/shifter assembly and you will see the switch.

 

[James Berres]

I did a couple tests to see if it was that I wasnt able to start the boat in either forward or reverse. Are there anymore tests I can do for this or a visual check?

 

[USAF_Pride]

If it is rev limiting, it is in that circuit.

 

[racerxxx]

If you CAN'T start the boat in F or R then that SHOULD rule out the neutral start switch--which has the rev limit function of the MPEM tied to it. Boat out of water, start boat, put in F, can you get past 3500 RPM? If you wanted to check the switch you can check the continuity of it with a meter, it's either open or closed.

If there was enough exhaust fumes in there then you could have been choking out the engine, but just see what happens out of the water. Have you done a compression check?


Here's a video I took of the rev limiter in action on my Speedster. You can see when I take it out of neutral and go in forward.

[video=youtube;Zoxqd7HMlto]https://www.youtube.com/watch?v=Zoxqd7HMlto[/video]

 

[Sportster-2001-951C-Stock]

If you have an exhaust leak you will want to fix that ASAP. The limit problem is gonna be an easy fix I think, if engine controller (MPEM) thinks it's in neutral it will limit revs to about the speed you reported.

 

[James Berres]

i fixed the exhuast leak yesterday but totally spaced trying the motor in forward to see if i can get it past 3500 rpm's i will try that tomorrow when i get home to see if i can get past 3500. another thing im new to boats should i hook a battery tender up to the battery when its not in the water?

 

[Sportster-2001-951C-Stock]

Some thoughts on battery maintenance: If your boat has a battery switch, than I think it's best to turn off the battery switch before connecting the battery tender if possible. The reason is our MPEM's are sensitive to "dirty" voltages so it's best not to take any chances with charging the battery while it's connected to the MPEM.

If my Seadoo boat didn't have a battery switch then I'd disconnect the negative battery cable before powering on the maintainer. (fear of possible MPEM damage)

On mine I turn off the batery switch before powering up the maintainer and I've decided it's only really necessary to top up a healthy battery every few months so I power on the maintainer occasionally to find out if the battery is up to snuff by watching for the green light. If the battery repeatedly takes some time (more than a few minutes) to come back to fully charged, there may be some parasitic losses in the system (such as depth finder or stereo radio may be drawing current) or the battery itself may be well past it's prime. In this case the problem should be looked into and isolated if possible.

One quick way to ruin an otherwise good wet cell lead acid battery is by accidentally giving it too much love with a low-quality charger. Fortunately, newer battery tenders are quite an improvement over the older battery chargers known for boiling out an expensive battery.

Another option for some cases: I keep several batteries here constantly connected to a maintainer with a daily timer that switches on the maintainer for 30 minutes each day. These are backup batteries in case someone needs to borrow one for the day.

The other thing is if the battery is allowed to discharge flat by more than 50% of capacity then each time this happens the recovery is only like 95~97% of the previous level so this is why it's best not to let it become too far discharged.

 

[James Berres]

Alright mini update I tested the motor and in reverse and I can rev it past 3500 rpm so ill be taking it out tuesday to see if she runs.

 

[racerxxx]

What about in Forward?

 

[James Berres]

Yeah it goes above 3500 rpm in forward too I thought I wrote that damn phone lol

 

[racerxxx]

LOL, just checking. Gotta love technology!

 

[James Berres]

Alrught heres an update. I fixed the exhaust hose and the boat flies and sounds awesome. Then the hose came off in the bay and I had to limp back to the ramp lol I guess I have found my issue. Thanks for all the help guys.

 

[James Berres]

Alright I got another problem I think fml. So im out having fun I come home to flush the motors and I cant get the starboard motor to start it cranks and thats it the oil light is on now. But the port side motor starts right up and I was able to flush it any thoughts guys.

 

[USAF_Pride]

Pull the plugs and see if is flooded

 

[James Berres]

So I pulled the plugs not sure what flooded means but they were pretty dirty and look like crap. I cleaned them off and put them back in and it still didnt start

 

[Sportster-2001-951C-Stock]

First of all, hopefully the engine isn't flooded with water from the hose or using the boat with one engine shut down. If the engine has water inside the crankcase or cylinders you have to get the engine back running right away, before the reciprocating assembly begins corroding.

If it's just fuel flooded that's a much less serious issue.

 

[James Berres]

I didnt hook the hose up at the house. I was still trying to get it to turn on. Both engines were on in yhe water and I shut it off at the dock brought my trailer down then started both motors up again and pulled it out of the water and brought it home. Are there anymore tests I can do?

 

[Sportster-2001-951C-Stock]

Good, so there's no rush to dry the water out of the motor. The other type of flooding is fuel flooding which can be found if you remove the spark plugs and place them on the two grounding posts to avoid stray sparks that can cause a bilge fire.

Then, open the throttle for the engine completely to full throttle and crank the engine while the sparkplugs are out, this will dry out any fuel inside a fuel-flooded engine.

If by cranking the engine while the sparkplugs are installed the plugs become wet with fuel this indicates there is too much fuel in the engine.

There are a few things necessary for an engine to run: spark, fuel, compression all must be there and it's a process of elimination to determine which one is inadequate.

For instance, if you think the engine isn't getting fuel then you can add fuel through the carburetors. You can use a spark checker to determine if spark is missing and you can use a compression tester to determine if the cylinder compression is adequate.

I keep a spray bottle (like a windex bottle) that has 32:1 pre-mixed gasoline+oil on my bench in case I need to find a fuel starvation issue. I will often install a new set of properly gaped spark plugs first thing off the bat, and I always check the cylinder compression when I suspect there may be a problem. Almost every customer engine I work on I will do this before installing new spark plugs, so I don't waste time.