Marcus252

I have a 1998 baja 252 boss with a stock 454 MPI 310hp. I have tried some different props and still can't trim over 1/4 on the gauge. First prop was a 23p mercury mirage three blade, the hole shot sucked and could only trim 1/8 on the gauge before blowing out, and still run over red line about 5000+rpm 50mph. Next I tried a 22p four blade and it worked better but could only trim 1/4 on the gauge before blowing out still run over red line and lost 1 mph (49mph). last I tried a 21p three blade and about the same hole shot as the 22p but could only trim 3/16 on the gauge and lost 3-4mph(46mph) Does anybody know what can help me from blowing out when trimming and what the top speed of my boat is supposed to be. I would love to get around 60mph

smokin' gun

iTrader: (30)

is their any chance you had the drive off the boat for any reason .their is a part referred to as the celery stick on the rear trim pin if put on the wrong side you will have the prob your getting

Marcus252

No, never had it apart. how hard is that to check?

Fixxxer22

I wouldn't use the gauge as the make or break. you could have a bad sender and you are over trimming and blowing the prop out. is the boat new to you? how many hours on the engine? she could just be tired.

tinman565

Don't look at the trim gauge. Trim it up till you stop gaining speed..then trim it back a little.

nailit

+1 on tinman..

my trim gauge acts crazy. I dont' keep my gps on, so I don't gauge by speed, but backwash coming from prop and boat attitude. Should have some backwash, but if your throwing rooster tail, its probaby more for looks than speed on our boats anyway!

Doubt you get 60.. I run at 60-63 with the 454mag 385. Best ever was 64.7 with 2ft chop and 40 degrees. that was with at 23m+ and running about 49-5k r's

wierd that your speed seems a lil low if running 5k and only 50mph.. do you have standard 1.5? I would say you would probably should be at 50-52 with the 310hp though

oh, are you going by gps??

A.O. Razor

Ok. Several things don't add up, so here is a bunch of Q's

1. Is your boat bottompainted? (Can create exessive slip)
2. Hook in hull? (See question 1 and it can mess up your running attitide ect.)
3. Are your speed GPS? (Needs to be!)
4. Drive gear ratio? (Your prop slip is off the wall. 29% with a 1.5 gear and 22 with 1.65. That is not normal)
5. Make/Model prop? (Impossible to give info without)
6. Tach is vorking correctly? (See question 3)
7. Do you know where neutral trim is, compared to your gauge? (You need to)

If you are spinning your motor @ 5000 s. you are way too high for that engine. 4600-4700 is the place to be.
Also you won't get 60+ from that setup. 53-55ish.

Regarding your trim. When your boat is on the trailer. You will need to find out where neutral is. Trim to your propshaft is parralel with the keel, and mark your gauge. Trim out without useing the trailer switch, and mark your gauge at this point. Then you have your trim range indicaded from neutral to max. When on the water. Trim in, and get up on plane. Trim to neutral and gun it. When you are not gaining anymore speed, trim out in small incements. You will notice speed gain. Keep hitting your trim swith in short clicks, when ever you are not gaining speed. Then when you, either don't get more speed, or maybe even slow down, when trimming out, back off the trim alittle.

bbladesprops

Wow,
Ok, not to take away from this thread but, if you want to cover a bunch of stuff quickly, Call us and we can cut throught the haze and maybe get you on the right track.
At BBLADES we have propped more Baja's than most any other propeller Co in the US. See
http://www.teambajamarine.com/forum/...splay.php?f=22
There are tricks to these boats.
One of the first things we will need to find out is whether the props you are using for testing have ever been adjusted, tweaked or repaired. Even repairs from the local propeller shop through red flags to us. We can help.

Brett
Today 12:13 PM