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-   -   1991 260 7.4 bravo speeds (https://www.offshoreonly.com/forums/baja/278329-1991-260-7-4-bravo-speeds.html)

Dtile 06-10-2012 12:59 PM

1991 260 7.4 bravo speeds
 
Just bought and old Baja coming from a 35 Fountain. Yes, down sized for health reasons. Very frustrating, might add since my 35 had twin blowers. Anyways, bought boat as little project (wasa mess) with son and I and getting frustrated on some speed tests -among other small issues. Though Im no mechanic, i always try to leave the "herd "stuff to "'Guy" my mechanic...i can turn a few wrenches and diagnose on occasion. Im getting 43mph max on GPS out of this 260 with stock 7.4 thru prop exhaust. I have replaced coil (was arcing), wires, plugs, exhaust among other non related items. motor has 200 hours but wasn't used a few yrs. I did have a similar boat and size in the mid 90's that I know did in the low 60's with same set up. I get 4600 rpm and the prop is a mirage plus 21 SS. I do get a "cough at WOT some times so Im thinking Carb issues/bad gas. Timing seems ok. I cant really go to fast now, dam lung cancer, just want to make sure i can get my kids up out of hole for tubing. What ya think this boat should get at WOT? I had 1/4 gas, and only one passenger when testing on GPS. River was calm, slack tide. Boat sat a few yrs, gas was on empty and I added stabilizers..replaced fuel filter and separators a few times...btw, rides nice at 4k-42k at around 38mph...
Just bottom painted with triton and drive is clean.
http://www.gamingkrib.com/tzhs1982/images/91.jpg
[IMG]http://www.gamingkrib.com/tzhs1982/images/912.jpg[/IMG]

JWoolever 06-10-2012 01:25 PM

I had the same boat, but it had a 454 magnum which was 365hp and in perfect conditions low load I saw Max of 62 MPH GPS with a I think a 21 Mirage plus.

If yours is a 7.4L it is either a 330hp and if a magnum 365hp.

If it is a 330hp you might see speeds of 55 to 59.

Powerquest_Baby!! 06-10-2012 02:31 PM

According to the prop slip calculator you are at a 30% slip!! Something is wrong...have you weighed your boat? Are you sure you are getting fully trimmed up? Your engine is getting to its max rpm so you are propped correctly but your speed is way off....very odd.

http://www.go-fast.com/Prop_Slip_Calculator.htm

Dtile 06-10-2012 02:52 PM


Originally Posted by Powerquest_Baby!! (Post 3706325)
According to the prop slip calculator you are at a 30% slip!! Something is wrong...have you weighed your boat? Are you sure you are getting fully trimmed up? Your engine is getting to its max rpm so you are propped correctly but your speed is way off....very odd.

http://www.go-fast.com/Prop_Slip_Calculator.htm

ya, odd, i have had many boats...trim is fine, non magnum. I did notice a slight warp in skeg about an inch and my new zinc above prop moved a bit so its not straight back, wonder if that both would limit so much mph? I do feel like its not biting the water as it should. That's new Micron paint, not triton, brain fart.

Dtile 06-10-2012 02:57 PM


Originally Posted by Powerquest_Baby!! (Post 3706325)
According to the prop slip calculator you are at a 30% slip!! Something is wrong...have you weighed your boat? Are you sure you are getting fully trimmed up? Your engine is getting to its max rpm so you are propped correctly but your speed is way off....very odd.

http://www.go-fast.com/Prop_Slip_Calculator.htm

you think water logged foam between stringers? no, haven't weighted it. Transom had no rot -first thing i check when buying boat...i have the sunpad off for rework, should be even lighter without that 3/4 plywood they use...

firehill19 06-10-2012 07:33 PM

Should get around 55 gps. I had a 91 260 for 14 years. Bought it in 1996 and sold two years ago. The 7.4 is 300 hp. Great boat with lots of cockpit space. Drawback is the 21 degree deadrise. Did lots of updating to mine including adding marine ac for overnights.

Dtile 06-10-2012 08:52 PM


Originally Posted by firehill19 (Post 3706426)
Should get around 55 gps. I had a 91 260 for 14 years. Bought it in 1996 and sold two years ago. The 7.4 is 300 hp. Great boat with lots of cockpit space. Drawback is the 21 degree deadrise. Did lots of updating to mine including adding marine ac for overnights.

What pitch prop, make?

firehill19 06-11-2012 02:56 PM


Originally Posted by Dtile (Post 3706476)
What pitch prop, make?

I believe it was a 21 or maybe even 19. I'm not one to play with props as it was on it when i bought it and never tried anything else. 4 blade Mach Sterndriver.

Dtile 06-11-2012 07:06 PM


Originally Posted by firehill19 (Post 3707047)
I believe it was a 21 or maybe even 19. I'm not one to play with props as it was on it when i bought it and never tried anything else. 4 blade Mach Sterndriver.

hmm, 4 blade might be interesting...though the last owner swawers he was getting 50 mph. Were you getting that speed with 1/2 tank? or almost empty? What speed at full tank if you recall? How ya like the 30 Boss?

Nightlife1970 06-11-2012 08:45 PM

I had a 91 with a 454 330 in it. With the stock 21p I would just get 50mph. I bought a 23p 3 blade prop from Overtons and could see 53. Mine did not have any tabs on it, so the only time it was fast was when it bounced.


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