1992 4.3 to 1999 4.3 swap - Maxum Boat Owners Club

boisebiker · 06-19-2018, 06:11 PM

I have begun the swap process to put a 1999 Vortec 4.3 block into a 1992 Maxum 1800 SR. I picked up the Maxum with a cracked block and I own a 1999 Stingray with a good motor but no interior. I have a much better chance of getting the Maxum on the water right away.

More to come.

boisebiker · 06-22-2018, 07:18 PM

Not ready to post pics yet but hope to in subsequent posts. Motors are almost ready to swap. Issues that I have found so far are:
1. Power steering hoses, they use different connectors at the rack and pinion.
2. Power steering cooler, 92 is mounted below block 99 is mounted behind block.
3. Shift interrupter switch, 92 is hard wired to harness so I am disconnecting the cables and leaving the shifter plate with its original engine.

I should be moving engines over tonight so I will be confirming the rest of the issues and cross my fingers wont find more.

mmwjr · 06-22-2018, 08:44 PM

Yes I forgot they changed steering assist cylinder in the mid 90’s.

boisebiker · 06-24-2018, 07:02 PM

Power steering hoses and cooler moved over without any issue. I was worried about the fitting at the pump but turned out a non issue.
The engine mounts on the maxim were taller and some kind of isolation mount so they had to be moved over.
The 10 pin electrical plug worked perfect, everything worked.
Fuel filter was tight. New style spin on is larger and sticks out more. We will see if the filter can be replaced without unbolting the bracket.
1999 engine is in and running. A small amount of alignment had to be done and outdrive bolted right up. We are excited to get it on the water. Pics to come.

mmwjr · 06-25-2018, 12:13 AM

Thanks for the update. Enjoy the season.

shrew · 06-25-2018, 03:44 PM

Quote:

Originally Posted by boisebiker

The engine mounts on the maxim were taller and some kind of isolation mount so they had to be moved over.

Reduces vibration.

boisebiker · 06-27-2018, 06:03 PM

Well first sea trial didn't go so well. First I remembered I didn't have enough power steering fluid so quick stop at Walmart. Got the boat in the water and first key turn gave a click and then everything went dead. The positive battery cable to the starter was not tight and I think the ground cable to the back of the engine needs to be replaced. We did get it to start and then found water leaks all over the exhaust joints. After tightening all of the clamps again they stopped. Please take note that I had my 16 year old son doing most of the wrenching, time he learns about engines. Filled power steering up and work the wheel, it never gets smooth or easy to turn. Then we pull away from the dock. Idles good, goes into gear no problem and we move out to edge of no wake zone. As soon as I push the throttle forward I head a grinding noise. Didn't hold it long enough to get on plane. Back to dock and we listen for a minute or so. Sound stays constant in forward, reverse or neutral. Back on trailer and we go home. It was successful in that it didn't sink, we found some issues and no one got hurt. Power steering is still a bear to turn and reservoir is full. We turned the wheel lock to lock multiple times with no change. I pulled the top of the outdrive, fluid was a little low and gears look good and no water in the oil.
I think I have narrowed it down to gimble bearing. Need to pull outdrive to make sure. As far as the power steering goes what do I look for? Can I service/rebuild the actuating unit?

mmwjr · 06-27-2018, 10:29 PM

Sounds like a bad steering cable. You can try lubing the guide tube to see if that helps.

Gimbal bearing don’t make a grinding noise, more like a moan.

boisebiker · 06-27-2018, 11:40 PM

Will look into the steering cable. Maybe you could call it a moan but definitely not normal.

Gugi47 · 06-28-2018, 08:59 AM

Quote:

Originally Posted by boisebiker

Will look into the steering cable. Maybe you could call it a moan but definitely not normal.

I would tested on land with garden hose and try the gearing and maybe you see anything

jparsons121 · 06-28-2018, 01:13 PM

Also, verify the plumbing on the pump. Did the feed and return hoses get reversed? Just thinking outside the box...

boisebiker · 06-28-2018, 04:17 PM

We had run the engine with garden hose before we took it to the lake and there was no noise. And there were no water leaks either but it is a different ball game when sitting full depth in water and putting an actual load on drive. I did run it some when I got back home to try and narrow it down. Once I pull it apart I will diagnose/repair/test until the problem is solved. Headed out for a 10 day, much needed, vacation. So it will have to sit for a few more days.

Thanks for the replies.

boisebiker · 06-28-2018, 04:19 PM

Quote:

Originally Posted by jparsons121

Also, verify the plumbing on the pump. Did the feed and return hoses get reversed? Just thinking outside the box...

It really isn't possible to reverse the hoses. Pressure hose has a threaded fitting on pump whereas the return line just pushes onto a nipple. On the actuator end the pressure line and return line are different sizes. But I appreciate the thought.

mmwjr · 06-28-2018, 05:04 PM

Quote:

Originally Posted by boisebiker

It really isn't possible to reverse the hoses. Pressure hose has a threaded fitting on pump whereas the return line just pushes onto a nipple. On the actuator end the pressure line and return line are different sizes. But I appreciate the thought.

Correct you have an Alpha drive not a Bravo which uses an internal raw water pump.

boisebiker · 08-01-2018, 08:23 PM

Here is an update. We have had the boat on the water almost every day for the past week and a half. I have discovered new issues, fixed old issues and even caused a few. Just to catch up, the steering issue is the cable and rack/pinion. We removed the cable, lubed everything as much as possible and put cable back in. Works great for now. The water leaks are a whole story in themselves. And the oil leaks are a brand new story. I will start new replies for each one. Overall the swap has been a success. We are having fun on the water and building memories.
It is possible to install a Vortec engine in place of a non-vortec engine without any major modifications. Fuel filter location, power steering hoses and cooler and engine mounts were all that needed attention. Everything else plugged in or bolted up they way it was supposed to.
Also grinding/wining noise was the gimbal bearing. I have a feeling I will be replacing it again soon because I don't think I got the grease ports lined up.

boisebiker · 08-01-2018, 08:31 PM

When we first put the boat on the water we found a few leaks, mostly exhaust bellows clamps not tight. After initial sea trials we had a lot of work to do and a long vacation. Once back from vacation we were gearing up for scout camp. This year we were doing it on a lake with multiple boats. On the 4th day I found about 10" of water in my bilge and pulled the boat out of the water. Could not find the water leak and only ran it for a couple hours on day 5. Had to run the bilge pump the whole time.
When we returned home from camp I started digging into water leaks. I found a missing o-ring on the block drain and a small drip from the power steering cooler. Not enough to make up for the amount of water entering my boat. So we tipped the bow way up and filled the back of the boat with water. It started leaking out of the exhaust. We had to pull the motor and found an exhaust flapper stuck in the y-pipe. It had worn a hole through the y-pipe before it passed to the outdrive. Lucky for me I had a spare y-pipe.
We have had it out 2 more times and no water leaks at all, yea.

boisebiker · 08-01-2018, 08:42 PM

Early in operating the boat we found that we were leaking oil into the bilge. It seemed small at first but soon became a significant issue. What a mess. While at scout camp we realized it was not a small issue so I began looking at it closer. It seemed to be coming from the distributor. So I pulled the whole distributor from the engine. Gasket looked good. I noticed that the RTV that seals the intake manifold had a gap in it. A quick squirt of brake cleaner showed the gap passed to the exterior. I sealed it from the inside with RTV and put distributor back on. 1 more day of boating and we went home. At home I realized we were still getting oil in the bilge. I sealed up the block and used low air pressure to check for leaks, there were 2 more on the intake manifold. I removed the intake manifold, cleaned it up and resealed it. Guess what no more oil leaks. 2 more trips to the lake have shown 0 drips of oil in bilge, Yea.

boisebiker · 08-01-2018, 08:47 PM

Picture of old non-vortec engine.

mmwjr · 08-02-2018, 02:24 AM

Thanks for the updates. Glad you’re figuring things out and enjoying her.

boisebiker · 09-28-2018, 11:00 PM

Boat originally had a 3-blade 19" pitch prop on it. Top speed was decent, pulled a tube well but took its time getting me out of the water on skis. So we tested a 17" 3-blade, much better getting me out of the water. Tests on a 4-blade 19" prop show good response on the bottom but still slow to pull me up. So I went out on a limb and picked up a Solas Amita 4-blade 17" pitch prop on ebay for $19.86. Wasn't expecting too much and half expected it to be the wrong item. It showed up in perfect shape and bolted right on to my Maxum. We are finding a good compromise, good pull but slower top end. Get me out of the water on skis or wakeboard in just a few feet. We are still trying to control the speed around 18-20mph for wakeboarding but can't quite hold it there. Either falls off plane or takes off. Maybe trim tabs will help????