Re: Marine Tex Or Jb Weld
There is a great deal of debate on the wisdom of drilling out a crack on a 120/140 block. Personally, I do not subscribe to the traditional thought that these cracks a freeze related as that are far too numerous. I tend to follow the belief that especially in the early 120/140 production, there was some type of fault and/or weakness in area just under that manifold on these blocks.
As for heating, if the area in question is just under the manifold, I think you will find it difficult to maintain the placement of the JB Weld on the vertical portion of a warm block ? assuming you are making this repair with the engine mounted.
That said, I still find them to be one of the most dependable, reliable and easy to maintain marine power plants available, and with the tremendous number produced, they are very cost effective. The reality is, if you spend some time looking around (craigslist for example), you can find a replacement for your current engine for well under the cost of a remanufactured engine. With a solid $300-$400 engine, and a $350 rebuild kit, you can have a very serviceable power plant for well under $1,000 that will last you many summers!! Hope this helps.