Hello,
I am still working on the same project I was a while ago. Anyway update from last time. Found out the old engine was shot. Low comp and pistons and cylinders were in bad shape.
I ended up buying a replacement which I thought would be a drop in... Anyway the fun has started now. It looks like the replacement motor is actually model# 25852C, a 25 hp model, and the old one was model#35R78R, 35 hp. I have done quite a bit of research and everything shows these a nearly identical... I have also heard the hp difference is due to the carb?
Anyway I ran into a bit of a problem last night. The crank shaft splines are different. The original motor has many more splines and a larger diameter. Not sure but maybe around 9 or so splines. Whereas the replacement, the 25 hp, has a smaller diameter and less splines maybe 3 or 4.
I see from boats.net and other parts websites that there was an old crankshaft that was obsoleted. Obsoleted was # 0323000, and the replacement is 0323533. Does anyone know if this accounts for the differences I am seeing between the two shafts?
I noticed the lower units between the two motors are different and the drive shafts are also different. Not sure what all the differences are.
Would swapping a drive shaft or lower unit be a possibility? I would rather swap the cranks if I can since I have all the parts, and do not need to put more money into this project. What is the best path forward?
I am still working on the same project I was a while ago. Anyway update from last time. Found out the old engine was shot. Low comp and pistons and cylinders were in bad shape.
I ended up buying a replacement which I thought would be a drop in... Anyway the fun has started now. It looks like the replacement motor is actually model# 25852C, a 25 hp model, and the old one was model#35R78R, 35 hp. I have done quite a bit of research and everything shows these a nearly identical... I have also heard the hp difference is due to the carb?
Anyway I ran into a bit of a problem last night. The crank shaft splines are different. The original motor has many more splines and a larger diameter. Not sure but maybe around 9 or so splines. Whereas the replacement, the 25 hp, has a smaller diameter and less splines maybe 3 or 4.
I see from boats.net and other parts websites that there was an old crankshaft that was obsoleted. Obsoleted was # 0323000, and the replacement is 0323533. Does anyone know if this accounts for the differences I am seeing between the two shafts?
I noticed the lower units between the two motors are different and the drive shafts are also different. Not sure what all the differences are.
Would swapping a drive shaft or lower unit be a possibility? I would rather swap the cranks if I can since I have all the parts, and do not need to put more money into this project. What is the best path forward?