Tommy in FLL
Seaman Apprentice
- Joined
- Apr 10, 2009
- Messages
- 44
I have a '96 C85 TLRU Yamaha motor attached to the back of my 16 foot Larson All-American.
-They picked a good name. This little boat was built as a "value-leader", which would lure buyers into the showrooms and yards, where they would be courted to their better products. Even the Larson website treats this boat as an "afterthought".
Funny thing? This boat looks GREAT. I live in a gated community in Fort Lauderdale, and the "bridge" really isn't a bridge, it is just a causeway about 70 feet long. The gates don't need a clicker or any other sort of special device- when you pull up to them, they open. Totally fake, but they DO do a good job of keeping scuzzy people out of our subdivision.
If you drive across the bridge into our island, and look to your right...you see my little boat. The lines of this silly, cheap little boat are OUTSTANDING. It really makes the whole view, and when we've taken it to downtown Fort Lauderdale and cruised the finger island canals, we've had owners of HUGE boats look at us and call us:
"That...that's a cool boat! A real classic! Who makes it?"
Despite the 5 inch letters on the stern "Larson".
The boat has great lines; if anything reminds me of this boat it is the late-model Dodge Charger automobile. Straight windshield, with a curved rear window line.
-Me and my significant other enjoy driving this boat up and down the canals of Fort Lauderdale. We do circuits around Wilton Manors, go downtown and tie up at the Stranahan House [we are both tour-guides there~], and otherwise run up and down all the canals and rivers in the town.
At wake speed. 1300 rpm~
If I firewall this engine it will run at 4800 rpm for about 30 seconds. I can probably hit about 40 mph- the speedometer is broken, but I know the mangroves are going past real damn fast!
Then the overheat warning horn goes off. I back off, kill the engine, and let it sit for 30 seconds. When I turn the key, it starts right back up and there is no horn.
A friend used his infra-red sensor on top of the thermostat cover, and it said 160 degrees. I can put my hand on top of that cover right after a hard run like this, and it feels hot, but it doesn't burn me. It is getting hot, but not excessively.
I've changed the thermostat. The PO [Previous Owner] did change out the impellor, and the tell-tale pumps with good pressure. To add injury to the whole situation, I have to tell you that last month I pulled the thermostat cover and pressure relief valve. I then lowered the engine into the water, and started it up. Sure enough- I had exhaust pouring out the t-stat cover.
Diagnosis: Exhaust in the coolant jackets.
First idea: Blown head gasket. I invited Bob back to my house after buying a new head gasket, and he was happy to come over and help me. I brought him over so that if he broke off any bolt heads....he'd be responsible for removing them via drill and reverse drill bits. This great guy agreed to this last.
We removed the head....and it was obvious that there was a TON of crud in all the jackets around the cylinders. We used a thin screwdriver to remove as much as possible, but from what I saw you could easily spend 5 days scraping and removing the crud that was growing out of those cooling passages!
In the end, we noted that the boat engine had a "chipped" cylinder. That is, the cylinder barrel had a "chip" on the outside. As a result, we had to use MarineTex to rebuild the barrel. When it was cured, we sanded and filed it down to what we thought it probably looked like. I Installed the new cylinder head gasket, and torqued it down to the official specifications. No leaks, and it was done right.
Hello? here it is, 3 months later, and I if I firewall the boat it still overheats within 30 seconds. I'm sure that the exhaust manifold gaskets are leaking; the head was done the right way, and all three spark plugs look the same.
The problem with the exhaust manifold bolts: Everyone has told me that most of them will snap off.
And what about the "Crud" in the cooling passages? This stuff is kind of a semi-clear gel. What chemical will remove crud from an aluminum block engine that has been used in brackish water?
Any advice?
T
-They picked a good name. This little boat was built as a "value-leader", which would lure buyers into the showrooms and yards, where they would be courted to their better products. Even the Larson website treats this boat as an "afterthought".
Funny thing? This boat looks GREAT. I live in a gated community in Fort Lauderdale, and the "bridge" really isn't a bridge, it is just a causeway about 70 feet long. The gates don't need a clicker or any other sort of special device- when you pull up to them, they open. Totally fake, but they DO do a good job of keeping scuzzy people out of our subdivision.
If you drive across the bridge into our island, and look to your right...you see my little boat. The lines of this silly, cheap little boat are OUTSTANDING. It really makes the whole view, and when we've taken it to downtown Fort Lauderdale and cruised the finger island canals, we've had owners of HUGE boats look at us and call us:
"That...that's a cool boat! A real classic! Who makes it?"
Despite the 5 inch letters on the stern "Larson".
The boat has great lines; if anything reminds me of this boat it is the late-model Dodge Charger automobile. Straight windshield, with a curved rear window line.
-Me and my significant other enjoy driving this boat up and down the canals of Fort Lauderdale. We do circuits around Wilton Manors, go downtown and tie up at the Stranahan House [we are both tour-guides there~], and otherwise run up and down all the canals and rivers in the town.
At wake speed. 1300 rpm~
If I firewall this engine it will run at 4800 rpm for about 30 seconds. I can probably hit about 40 mph- the speedometer is broken, but I know the mangroves are going past real damn fast!
Then the overheat warning horn goes off. I back off, kill the engine, and let it sit for 30 seconds. When I turn the key, it starts right back up and there is no horn.
A friend used his infra-red sensor on top of the thermostat cover, and it said 160 degrees. I can put my hand on top of that cover right after a hard run like this, and it feels hot, but it doesn't burn me. It is getting hot, but not excessively.
I've changed the thermostat. The PO [Previous Owner] did change out the impellor, and the tell-tale pumps with good pressure. To add injury to the whole situation, I have to tell you that last month I pulled the thermostat cover and pressure relief valve. I then lowered the engine into the water, and started it up. Sure enough- I had exhaust pouring out the t-stat cover.
Diagnosis: Exhaust in the coolant jackets.
First idea: Blown head gasket. I invited Bob back to my house after buying a new head gasket, and he was happy to come over and help me. I brought him over so that if he broke off any bolt heads....he'd be responsible for removing them via drill and reverse drill bits. This great guy agreed to this last.
We removed the head....and it was obvious that there was a TON of crud in all the jackets around the cylinders. We used a thin screwdriver to remove as much as possible, but from what I saw you could easily spend 5 days scraping and removing the crud that was growing out of those cooling passages!
In the end, we noted that the boat engine had a "chipped" cylinder. That is, the cylinder barrel had a "chip" on the outside. As a result, we had to use MarineTex to rebuild the barrel. When it was cured, we sanded and filed it down to what we thought it probably looked like. I Installed the new cylinder head gasket, and torqued it down to the official specifications. No leaks, and it was done right.
Hello? here it is, 3 months later, and I if I firewall the boat it still overheats within 30 seconds. I'm sure that the exhaust manifold gaskets are leaking; the head was done the right way, and all three spark plugs look the same.
The problem with the exhaust manifold bolts: Everyone has told me that most of them will snap off.
And what about the "Crud" in the cooling passages? This stuff is kind of a semi-clear gel. What chemical will remove crud from an aluminum block engine that has been used in brackish water?
Any advice?
T
