540 bulldog
 

Happy new owner of a 257 Powerquest with the 540 bulldog. Boat was purchased in TX and it's new home in Utah. The boat is running rich. TX 600' UT 4300', Does anybody have information on re-jetting the carb for my elevation. Called merc, there comment was to change props. That's for hp loss, not for running to rich. Any help is appreciated.

Start by going down at least 2 sizes all the way around (Holley???)and do a plug check. I had the same problem boating on Lk Tahoe and Powell. You will ultimately go down in prop size too. NA motors just dont make as much power at high alt's.

Dan

It is a Holley. I do have a good assortment of jets for a 750 Holley, I would think they will work on the 540 carb. On the prop, it is a 23p and looking for a mirage plus 21p for Pine view res. and lake power. The 23p should work great for Lake mead.

A 540ci/500 Bulldog and only spinning a 23" prop:confused: How much does your boat weigh???? Seems to me it should be around 4000-4500lbs and you should be able to/have to run more prop. What are WOT rpms???and mph???

257 Powerquest 4200 lbs, WOT 5050 rpm at 65mph, At previos owners elevation 600', ran WOT 5400 rpm

I agree with Griff...you should be able to turn a 26 bravo 1 with no prob. 28 Pantera with a 500 efi has no prob and it weighs over 5000

was it in the texas boattrader, if so was it the one saying runs with the big dogs, or leads the big dogs. im with the others. a 540-should be able to spin a 26 at least. maybe its a 454 w/ 540 decals, did you run the motor #s or did the prev owner just say it has a 540. if so maybe your gear ratio is 1.36 w/ would allow you to run a 23 i think. put on a 25mirage and go from there should be in low 70s there.:D

What color is the intake manifold?;)

I helped rig a 260 Powerquest with at 540ci/600hp with 1.50 drive. The best we could do was with a 25" labbed Mirage plus prop. It would do 73-74 mph @ 5200. We tried a lot of props and it liked the 3 blade the best, because it raised the bow, not the stern. The engine compartment on the 260 needed more air to breath and I expect the 257 is the same. I expect you will need to run a 23" prop and be in the upper 60s.

The 260 road a lot better in rough water above 70mph than it did at 65mph.

Bruce and Griff,
keep in mind he's running at 4300 feet elevation. His 470 pshp quickly drops to ~390 hp.
Unfortunatly it's just a fact that we deal with on a daily basis around these parts :(
Worst part is that this is one of our lower elevation lakes. We run up to 6000+. The motors become very tame so to speak.
Later,
Dave