bigbrownbuku
Master Chief Petty Officer
- Joined
- Sep 17, 2004
- Messages
- 885
Re: Merc 260 5.7L overheating
just had this problem with a 260 pinned it to the riser style. early style risers, the ones with the 3 inch to 4 inch rubber adapter run hot leading you to believe you have a rw cooling problem. it also adds about another 100 plus degrees of latent heat both sides of the carb causing vapour lock but thats another issue. the solution for me was to replace the risers which were wrong for that model with the 4 inch output/ newer style and downpipes that fit. these risers run 120 degrees cooler.
just had this problem with a 260 pinned it to the riser style. early style risers, the ones with the 3 inch to 4 inch rubber adapter run hot leading you to believe you have a rw cooling problem. it also adds about another 100 plus degrees of latent heat both sides of the carb causing vapour lock but thats another issue. the solution for me was to replace the risers which were wrong for that model with the 4 inch output/ newer style and downpipes that fit. these risers run 120 degrees cooler.