1990 Sunsport revs to 2000 rpm then won't go any faster. Reverse works fine

If it's weighed down, we won't be able to plane out and get to a cruising speed. If it's just me and a few two others, it'll slowly accelerate, but eventually get to an okay wakeboarding speed.

The engine revs easily to 5-6k rpms in reverse, but under load in forward, it struggles once it gets to 2000 rpms.

I initially thought it was a fuel delivery problem, but since it works fine in reverse, I'm wondering if it's a problem with the butterfly valves on the carb, or the throttle cable itself.

Has anyone seen anything like this on their boats?

How much weight are you pushing? The prop spins easier in reverse much like removing a screw . Do you still have points?

Yes, still has point style ignition system. I'll look them over today.

The weight I'm pushing when won't get above 22-2400 RPMs is just the boat loaded with wakeboard supplies and 4 adults.

Start with checking the dwell on the points. The points need to be replaced yearly . If you don't have a dwell meter you can set them with a clean feeler gauge. Set the points then the timing. If that doesn't help the carb will probably need a rebuild. I gave up on points I have 3 boats with 351 ford engines running on a GM HEI style distributors I am very happy with the results.

Everything seems to be working fine in the driveway when the engine is not under load. I noticed that I was low on transmission fluid, so I purchased a quart and filled it up. I'm taking it to the lake next week to test it on the water. I should also check the points and maybe give it a tune up before I go.

Here is an updated video I took today that shows the problem I've been having. https://youtu.be/uBkZyNnV2iE

Any thoughts?

Trans looks way over full should be to the line about 1 inch from the bottom of the stick. Did you check the points and timing? When did this problem start ? Was it running good last year? Where are you located?

Quote:

---

Originally Posted by michael hunter

Trans looks way over full should be to the line about 1 inch from the bottom of the stick. Did you check the points and timing? When did this problem start ? Was it running good last year? Where are you located?

---

Thanks for the insight on the fluid level. I'll pump it out and get the proper amount of fluid in there.

The problem started when we took it out for the first time this season. I believe it has been converted to an electronic ignition setup, so it does not have points. I'll take my timing light with me to the marina today to see what the timing looks like.

Find out what brand the ignition was converted to. What state are you in?

Quote:

---

Originally Posted by michael hunter

Find out what brand the ignition was converted to. What state are you in?

---

I'm in Utah. I couldn't find the ignition information. I'm very unfamiliar with ignition systems. I couldn't 100% confirm I don't have points. I took the distributor cap off and didn't see any capacitors, there is a plate with a black electronic module on it. When I remove the plate, below is what appears to be weights and springs surrounding the distributor (That's where the points would be I think) I don't see any points, just some springs and weights.

I started to do some additional testing and got to the compression test. Looks like my entire engine has low compression. I thought it was odd that all of the sudden, the boat would run like that after sitting over the winter. Will an engine lose compression like after a few months?

I need to do some research as to what to do now. Am I toast? If I remember correctly, low compression on all cylinders might be caused by a slipped timing chain. Any other recommendations other than a full engine overhaul?

I used an autozone compression tester, I want to make sure the tester is functioning properly before I dig too much deeper into the problem.

Here is a video of me testing compression and fuel lines. https://youtu.be/BEM4MJX4L5E