About a month ago I bought my first boat. Its a 1997 Larson 206 Sei Bowrider with a Merc 5.7LX and Alpha 1 outdrive. The hour meter had 488 hours on it. I bought the boat directly from the original owner. It looks like it has been well cared for (most of my neighbors thought it was only a couple of years old). All of the fluids looked good and at the proper levels. The day I looked at the boat it was raining, so rather than putting it in the lake he ran it in the driveway with muffs on. It sounded great and ran smooth at all RPMs, I haven't heard too many 18 year old motors sound that smooth.
I brought it home and put it in storage. Over the Memorial Day Weekend we took it for its maiden voyage. We hit two lakes in two days and had a lot of fun. The first day everything ran great. The second day it also ran well most of the day. Towards the end of the day it would act and smell like it was flooded after we stopped and shut the motor off to change tube riders etc. It also seemed a little sluggish when starting off pulling the tube with two kids on it. Everyone was getting tired so we loaded it up and came home. The next day at home I put the muffs on and it started right up and ran fine.
Yesterday we packed everyone up and headed back to the lake. When I tried to start the motor to launch off the trailer the engine would not start and had that flooded sound/smell. I put the throttle in the wide open position just like the manual recommends and it started after a few tries. We idled out of the launch area and onto the lake. When I opened it up to cruise across the lake it backfired real bad a couple times and started a pretty bad tick/knock. I took it back to idle and the knock stopped. We started off again and once I got above 2000-2500 RPM the knock came back, so I idled back to the dock, loaded it up and came back home. In the driveway with the muffs on it wasn't consistent, but I could replicate the problem.
Here are the details:
MCM 5.7 Litre LX
Engine S/N - 0K276257
Transom S/N - 0K272749
Drive S/N - 0K242471
Engine Hours: 494.1
Today the oil looks good with no signs of water. The oil fill caps and inside the valve covers also show no signs of water. There does appear to be some blow by oil at the breather tubes both at the valve cover and above the spark arrestor, but nothing excessive. This morning I pulled the plugs. 1, 3, 5, 7 (port) were dry but black with carbon. 2, 4, 6, 8 (starboard) were all varying levels of moist (smelled like oil/gas) and also black with carbon. I performed a compression test: 1 - 170 psi, 2 - 150 psi, 3 - 175 psi, 4 - 10 psi, 5 - 165 psi, 6 - 30 psi, 7 - 170 psi, 8 - 140 psi. I took the starboard valve cover off and inspected the lifters, springs and lifting rods and can see no obvious damage.
It seems pretty obvious that I at least have a blown head gasket, and at worst...well worse. Based on everyone's experience and the book I have written here is it reasonable to think it is just the gasket? If it is, can it be done "in frame" or does the motor have to come out? Ball park, how much time should it take, and what do you think it will cost?
On the way home I contacted a couple of repair shops anticipating I would need one. No one can look at it for a couple of weeks. We have a vacation planned and paid for over the Independence Day weekend, so I'd like to get it up and running before then. I am pretty mechanically inclined (grew up on a farm, owned/operated trucks and heavy equipment, etc.), so I have the ability and most of the tools to do the work. Time and a good service manual are the only things I'm lacking as long as the motor doesn't have to come out.
Any insights or advice would be greatly appreciated. Thanks in advance.
I brought it home and put it in storage. Over the Memorial Day Weekend we took it for its maiden voyage. We hit two lakes in two days and had a lot of fun. The first day everything ran great. The second day it also ran well most of the day. Towards the end of the day it would act and smell like it was flooded after we stopped and shut the motor off to change tube riders etc. It also seemed a little sluggish when starting off pulling the tube with two kids on it. Everyone was getting tired so we loaded it up and came home. The next day at home I put the muffs on and it started right up and ran fine.
Yesterday we packed everyone up and headed back to the lake. When I tried to start the motor to launch off the trailer the engine would not start and had that flooded sound/smell. I put the throttle in the wide open position just like the manual recommends and it started after a few tries. We idled out of the launch area and onto the lake. When I opened it up to cruise across the lake it backfired real bad a couple times and started a pretty bad tick/knock. I took it back to idle and the knock stopped. We started off again and once I got above 2000-2500 RPM the knock came back, so I idled back to the dock, loaded it up and came back home. In the driveway with the muffs on it wasn't consistent, but I could replicate the problem.
Here are the details:
MCM 5.7 Litre LX
Engine S/N - 0K276257
Transom S/N - 0K272749
Drive S/N - 0K242471
Engine Hours: 494.1
Today the oil looks good with no signs of water. The oil fill caps and inside the valve covers also show no signs of water. There does appear to be some blow by oil at the breather tubes both at the valve cover and above the spark arrestor, but nothing excessive. This morning I pulled the plugs. 1, 3, 5, 7 (port) were dry but black with carbon. 2, 4, 6, 8 (starboard) were all varying levels of moist (smelled like oil/gas) and also black with carbon. I performed a compression test: 1 - 170 psi, 2 - 150 psi, 3 - 175 psi, 4 - 10 psi, 5 - 165 psi, 6 - 30 psi, 7 - 170 psi, 8 - 140 psi. I took the starboard valve cover off and inspected the lifters, springs and lifting rods and can see no obvious damage.
It seems pretty obvious that I at least have a blown head gasket, and at worst...well worse. Based on everyone's experience and the book I have written here is it reasonable to think it is just the gasket? If it is, can it be done "in frame" or does the motor have to come out? Ball park, how much time should it take, and what do you think it will cost?
On the way home I contacted a couple of repair shops anticipating I would need one. No one can look at it for a couple of weeks. We have a vacation planned and paid for over the Independence Day weekend, so I'd like to get it up and running before then. I am pretty mechanically inclined (grew up on a farm, owned/operated trucks and heavy equipment, etc.), so I have the ability and most of the tools to do the work. Time and a good service manual are the only things I'm lacking as long as the motor doesn't have to come out.
Any insights or advice would be greatly appreciated. Thanks in advance.
