bertram31.com

Good morning - I have enjoyed this site for some time now and finally have a Bertram 31 in my shop to refit for my customer.
I took delivery of the boat on Saturday and had a nice ride with the current Crusader XL 502s. Unfortunately I will be pulling these this week (if anyone is interested they will be for sale).
My plan is to install Yanmar 4LVs, at 250HP, once I get the bulk of the refit done. Does anyone have experience on a B31 with these engines?
Will I need to change the struts, shaft size, and log angle?
Thanks for any input as I am more of a glass and paint guy than mechanic but am not totally clueless.

Good luck with the refit.

I'd think it difficult for anyone to say whether you need to change anything or everything from the motor beds to the running gear. 502's were not stock so someone converted what the boat had to what is now has...obviously. If I am anything it is Captain Obvious. What is not obvious is whether the job was done right.
If I was putting 502's in, I would beef up the beds and upgrade the running gear to 1-1/2" shafts. That would be more then adequate for 250 Yanmars in my opinion. As to changing the shaft angle...they have been done with stock angles and run well. Would I change for better performance if everything was in place to accept with the Yanmars?? I doubt it. Not unless I had real life numbes on the benefits of changing the shaft angle.
Now just because I would beef up beds and the running gear to install 502's, that does not mean everyone would. In that case if your going to have to do bed work, change shaft logs, pull struts to bore larger or replace them...well a flatter angle is more efficient and makes sense to take advantage of going that route as its all being redone anyway.

Now what your customer wants, how deep his pockets are and how far he's will to reach into them is a different story.

If you can tell us what the setup is or show some pictures you'll get better answers.


and welcome aboard!

Is it set up direct drive? Just wondering if I know the boat.....