AntiqueTbird
Cadet
- Joined
- Jul 1, 2012
- Messages
- 29
Hello Fellow Boaters,
I want to share a tale of exuberance and sorrow. I have a 1979 Thunderbird Formula 18 O/B with the original 1977 Johnson 140 Seahorse. The engine turned over well and ran when I bought it And I got it for a very good ($0) price. I knew it would need a deck replacement and a transom and being that I've always wanted to do that sort of a thing , I did. New stringers, knife running from the bow eye to the transom and full beam transom capturing the Tow eyes with SeaCast pourable Composite. I then laid in a new poly gas tank and complete deck made of expanded pvc sheeting (1/2") and poured in the space between deck and hull with 4LB floatation foam. Lots of days weeks and months of work cursing, blood and sweat and the motor was ready to be put back on. The motor had been serviced heavily by a very trusted shop. It turned out that it had been severely overheated. So it received all new bearings, connecting rods, pistons, two resleaved cylinders, a fabricated exhaust horn since they are not available anywhere, and many many new parts. Put it back on the old girl and she was great for two years. This past week I took her out of storage and did the things that I believe are normal maintenance things. New fuel filter, new fuel pump(cant find rebuild kits anymore), new water pump kit, new spark plugs, and carbs cleaned. even got her a new shiny S.S. prop. New fuel mixed 50:1 with XD30 and Rec90 Took her out motored around slow. she fired right up with the warm up lever and a little choke. checked fuel flow in the filter Looked great. Checked blubber holes Moving water well. She was warmed up and I was ready to let her horses run wild as I made it to the part of the intracoastal where running is allowed. Hammer drops, She grunts to life and is on a plane in a heartbeat. Seconds later, UH OH. The sound of the overheat alarm. Before I could even respond the boat slowed dramatically, laid down in the water knocked loudly then silence. I kedged my way back to the ramp so as not to risk further damage as I was unsure what caused the sudden, unexpected, hot seize.
It turns out that My now 5 year old Diverter tubes are a swollen mass blocking off the proper flow of water on the starboard side of the head. Magically my compression is still good in order 120, 124, 122, 119 . even more surprising is the fact that the piston that is damaged (needs to be replaced) has the third best number. I am doing the work myself this time. Not because I don't trust the shop I took it to before but time(very critical), and money. Besides I now have a suitable place to tear a motor down and rework it. I have the proper tools and know how. Before I lacked an appropriate place to do this sort of thing.
So the overall problem seems to be these diverter tubes. Is there and alternative? Is there something better?
I want to share a tale of exuberance and sorrow. I have a 1979 Thunderbird Formula 18 O/B with the original 1977 Johnson 140 Seahorse. The engine turned over well and ran when I bought it And I got it for a very good ($0) price. I knew it would need a deck replacement and a transom and being that I've always wanted to do that sort of a thing , I did. New stringers, knife running from the bow eye to the transom and full beam transom capturing the Tow eyes with SeaCast pourable Composite. I then laid in a new poly gas tank and complete deck made of expanded pvc sheeting (1/2") and poured in the space between deck and hull with 4LB floatation foam. Lots of days weeks and months of work cursing, blood and sweat and the motor was ready to be put back on. The motor had been serviced heavily by a very trusted shop. It turned out that it had been severely overheated. So it received all new bearings, connecting rods, pistons, two resleaved cylinders, a fabricated exhaust horn since they are not available anywhere, and many many new parts. Put it back on the old girl and she was great for two years. This past week I took her out of storage and did the things that I believe are normal maintenance things. New fuel filter, new fuel pump(cant find rebuild kits anymore), new water pump kit, new spark plugs, and carbs cleaned. even got her a new shiny S.S. prop. New fuel mixed 50:1 with XD30 and Rec90 Took her out motored around slow. she fired right up with the warm up lever and a little choke. checked fuel flow in the filter Looked great. Checked blubber holes Moving water well. She was warmed up and I was ready to let her horses run wild as I made it to the part of the intracoastal where running is allowed. Hammer drops, She grunts to life and is on a plane in a heartbeat. Seconds later, UH OH. The sound of the overheat alarm. Before I could even respond the boat slowed dramatically, laid down in the water knocked loudly then silence. I kedged my way back to the ramp so as not to risk further damage as I was unsure what caused the sudden, unexpected, hot seize.
It turns out that My now 5 year old Diverter tubes are a swollen mass blocking off the proper flow of water on the starboard side of the head. Magically my compression is still good in order 120, 124, 122, 119 . even more surprising is the fact that the piston that is damaged (needs to be replaced) has the third best number. I am doing the work myself this time. Not because I don't trust the shop I took it to before but time(very critical), and money. Besides I now have a suitable place to tear a motor down and rework it. I have the proper tools and know how. Before I lacked an appropriate place to do this sort of thing.
So the overall problem seems to be these diverter tubes. Is there and alternative? Is there something better?