260hp to 245hp conversion

**WOT77** · 11-30-2022, 04:38 PM

Heys guys looking to convert my 260 hp pp motor to a carb 245hp. Just looking for some insight on things.
1. What carbs are best for this application?
2. Do I have to change or block anything on the reed/manifold/intake?

Any other insight that I am overlooking is welcomed.

Many thanks!

**rgsauger** · 12-01-2022, 12:17 AM

Welcome to the forum!

Did I actually just read that you want to go down in horsepower?

**WOT77** · 12-01-2022, 07:13 AM

You are correct. I know its unusual as most upgrade but it's more so what I have and am working with at this stage. It's basically a powerhead without intake. There's no efi or carbs on it and weighing out the cost for the whole efi system and considering I have sets of carbs just works with my budget at this stage. If only I knew what set would work. Any insight is greatly appreciated!

**mach351** · 12-01-2022, 08:18 AM

I ran carbs on a 280. Ran very good. Any set of 200 carbs will work. I personally used WHM-21’s. If you have an efi front half you have to either plug the injector holes, or leave the injectors in place and get creative with a custom carb linkage.

**rjdubiel** · 12-01-2022, 08:46 AM

What carbs do you have at the shop? WHM carbs with a 1.312 ventrui is what you want with the pumper or not. Or a WH carb like a WH 20, 22, 31, 46, all would work depending on what you are trying to do as WH carbs you have to be careful running half throttle if you jet them done to get on the line at WOT (lean in the mid range). I WH carbs on my 245 (carb 260) and ran 90+ jets (very fat all around) all the way down to 72 mains (only was down here for 800 foot drags, not on the lake or river).

Again what are you trying to do and what do you have for carbs will let the carb guys here know what you should run.

**David** · 12-01-2022, 12:24 PM

I thought that the 260s and 245s had the same porting. 15 HP from changing to EFI seemed like a lot. Was it that much?

**WOT77** · 12-01-2022, 01:48 PM

Thank you for your reply! That helps alot!

**tlwjkw** · 12-01-2022, 01:54 PM

in production form tha efi would turn higher producing higher horse power rating... so its believed... i liked tha carb version myself but back then ya didn't have tha adjustable/tunable electronics that developed later on.... tha 11350 that you could change tha chip in started tha whole thing....

**WOT77** · 12-01-2022, 02:01 PM

Honestly I don't know exactly what I have I'll have to take a good look and figure it out. The guidance that has been provided by yourself and others so far is very enlightening. I've been researching it and trying to pinpoint exactly what I need to do and your comments help to confirm some of the info I've been finding. I'll try and attach some screenshots of this info and posts so everyone can take a look at and maybe help rule out any false info and possibly confirm which info is correct.

Thanks again guys!

**rjdubiel** · 12-01-2022, 02:05 PM

Easiest is to take pics of what you got and find out what carbs you have and there are plenty of guys here that are willing to help you get it all set up weather you decide to run EFI or Carb!

**moatorbotin** · 12-01-2022, 02:17 PM

Originally Posted by David

I thought that the 260s and 245s had the same porting. 15 HP from changing to EFI seemed like a lot. Was it that much?

I always thought they were pretty similar but the carb was derated to encourage EFI purchases.

**tlwjkw** · 12-01-2022, 02:19 PM

Originally Posted by WOT77

I'll try and attach some screenshots of this info and posts so everyone can take a look at and maybe help rule out any false info and possibly confirm which info is correct.

Thanks again guys!

port side, front and rear will work......

**WOT77** · 12-01-2022, 02:42 PM

Click image for larger version.

Name: Screenshot_20221129-212942_Samsung Internet.jpg
Views: 24
Size: 317.7 KB
ID: 512900

Click image for larger version.

Name: Screenshot_20221130-005404_Samsung Internet.jpg
Views: 23
Size: 245.8 KB
ID: 512901

So this is some of the info I've come across. In one of the pics you can see it lists what carbs for different applications but it's not very specific as to what size for each 2.5l application. But with everyone's help here it is helping to narrow things down.

In another one of the pics is a s+f thread where it helps out with the jetting range for different applications (2.0,2.4,&2.5) Which rjdubiel has confirmed to be truthful and added his knowledge in his real life experiences. Thank you!

I'll dig through my stuff, take some pics and post what I have as he's suggested and hopefully I have a set that I can match up.

Thanks again everyone!