Winter project wanted

[bc's xtb21]

I have a xtb21 with an old vertical 175 2.4 merc. I have already done a few mods to this engine lwp, ex.tuner. It runs decent but I would like to find a 2.4 or 2.5 powerhead to build over the winter,already have a set of wh-20 carbs and velocity stacks plus 3 petal fiber reeds I bought off Tooter. Any suggestions as to what mods could be made, would like to end up in the 240-280hp range. Guess what I am asking is what would be the best block/reed configuration to start with. As always thank for the info!

 

[HO]

BC,
It will be much easier to get more hp from the 2.5 than the 2.4. Parts availability and knowledge for the 2.5 will be easier to find as well. It has more torque and will carry the xtb better.

You can find port maps for the 2.5 if you do a search.

If your 2.4 is a chrome bore motor then changing the port heights is very difficult without putting in steel sleeves.

John

 

[bc's xtb21]

Thanks for the info!

 

[HO]

BC,
I meant to tell you that I had a modded 2.4 on an xtb. I really liked the combo but would go with a 2.5 for my next engine for the reasons in my first post.

Good luck

John