88 Bayliner top speed

[G.I. Jim]

I recently bought a 1988 Bayliner Cobra 1800 BR with a force 125 and was curious about my top speed. I took it out over the weekend had two people with fishing gear and at WOT I was right over 30 mph. Does this speed sound about normal? Is there anything I can do to increase the top speed?

 

[mixerjv]

Re: 88 Bayliner top speed

My 19' Bayliner '89 cuddy with an Evinrude 120hp (formerly 125 Force) has a top speed of 40mph (15 pitch prop).

Not sure, but 30mph seems low for a boat that weighs less than mine. What RPM's are you running at 30mph? If you don't have a tachometer I would definately get one (about $100).

 

[G.I. Jim]

Re: 88 Bayliner top speed

Not 100% sure I did glance at the tach and I believe it was in the mid 5's

 

[NYBo]

Re: 88 Bayliner top speed

How are you measuring speed? The speedometer in the dash is notoriously inaccurate. GPS is the way to go.

 

[mixerjv]

Re: 88 Bayliner top speed

If you're right with the 5500rpm then there is nothing wrong with the engine (as long as the prop is free of defects)- right where it should be.

NYBo is right- the stock water pressure speedo's are very inaccurate and usually read low. The gauge space is better for a GPS or a fishfinder (if anything- knowing depth comes in handy in certain bodies of water and is more important than speed)

 

[G.I. Jim]

Re: 88 Bayliner top speed

The reading was from the boats speedometer, my depth finder doesn't have speed (at least that I know about), but i can bring my trucks GPS with me next time to check for sure.
Do they make any kind of performance add ons for this motor not necessarily for top speed but overall performance too?

 

[mixerjv]

Re: 88 Bayliner top speed

"Do they make any kind of performance add ons for this motor not necessarily for top speed but overall performance too? "

No - Motor is extinct. Force started as Chrysller, was bought by Bayliner in the early 80's, then Bayliner was bought 1986 by Brunswick (Mercury Outboards). Lasted into the ninetees and was shutdown. None of the original Force engineering survives in modern engines today.

If you are hitting 5500 rpms, and have the proper propeller, there is nothing more to be done in the engine relm.

Is the bottom of the boat clean? Was it docked/moored and look like coral reef?

 

[G.I. Jim]

Re: 88 Bayliner top speed

The bottom of the boat is clean

 

[ezmobee]

Re: 88 Bayliner top speed

I would think you should be able to hit at least 35 in that, perhaps 40. Are you sure you're not lugging around a bunch of extra weight in the form of soaked flotation foam?

 

[G.I. Jim]

Re: 88 Bayliner top speed

I have no idea, how would I check that?

 

[ezmobee]

Re: 88 Bayliner top speed

One option would be to have a good idea what your boat/motor/ trailer SHOULD weigh, and then weight it at a public scale. (I don't have any good tips on how to research this information). The other way would be to take a core sample. Basically drill a hole in the floor, shove a notched piece of PVC pipe down into the foam all the way to the hull and see if what you pull out is wet.

 

[G.I. Jim]

Re: 88 Bayliner top speed

Ok thanks for the tip I'll try to see if I can find some specs on the two if not I guess I'll put a hole in my boat.

 

[mixerjv]

Re: 88 Bayliner top speed

Waterlogged foam shouldn't slow it down too much, maybe 5 mph at the most.

Again, he is hitting 5500 rpms, if the boat is really bogged down, it wouldn't plane, nor would it hit 5500.

I still think it's a case of bad speedo.

For reference, however, my '89 bayliner cuddy with trailer weighs 3000 lbs.

Nadaguide.com values have weights, but I've found them inaccurate sometimes.

To get the weight of the boat alone, weigh car, trailer, boat, then dump the boat in the water, go back and weight the car and trailer.

I don't think it's worth drilling a good deck.

 

[G.I. Jim]

Re: 88 Bayliner top speed

Ok finally got back out to lake. Took the gps with me to double check speed, 31mph right under 5000 rpm, 550lb load and a full tank of gas.

 

[mixerjv]

Re: 88 Bayliner top speed

The ratio of 5000rpm to 31mph seems fine, However as you suspect the boat probably did go a bit faster when new.

Remember, your're dealing with a 22yr old boat & engine.

I would start with a compression check of the engine to see where it's at if you haven't. If the numbers check out then perform a tune up, including plugs, carb rebuild, & timing.

Personally, I am not a big believer in the water-logged-foam-slowing-down-the-boat theory. My similar boat -19' cuddy, which was a salvage purchase after it had sunk, no doubt has water logged foam yet I can still do 41 mph.

Alternatively you can consider switching to a newer Merc or Evinrude. Weight wize your Force weighs 300lbs, My '92 Evinrude weighs about 380 as does the newer Merc optimaxes and Evinrudes. You're good to 400lbs engine weight. Mercury for 2010 brought back a 125hp Optimax (125 had not been available from any manufacturer for a couple of years, you had to settle for a 115)

 

[G.I. Jim]

Re: 88 Bayliner top speed

Yeah I know it's an old boat and motor, I didn't expect it to run as good as it does so I am happy with it but I just want to make sure its performing as well as it should be. I'll check the compression after the holiday and post results to see if they sound good.

 

[NYBo]

Re: 88 Bayliner top speed

The age of the boat and motor have absolutely nothing to do with it, at least not directly. Is 5000 RPM your motor speed at wide open throttle? Is the prop in good condition? Even seemingly minor damage can reduce top speed by a significant amount. Have you experimented with different trim angles?

 

[G.I. Jim]

Re: 88 Bayliner top speed

Yeah the 5000 was at WOT. It is an old prop and has some very minor nicks on the edges. Trim angles: yes and it made no difference in top speed.

 

[ever.zeez]

Re: 88 Bayliner top speed

The age of the boat and motor have absolutely nothing to do with it, at least not directly. Is 5000 RPM your motor speed at wide open throttle? Is the prop in good condition? Even seemingly minor damage can reduce top speed by a significant amount. Have you experimented with different trim angles?

absolutely correct dear
100% the 5000RPM
booooooooooooooooooooooooooooooooooost

 

[ifallsguy]

Re: 88 Bayliner top speed

You might want to wax that hull down. Might be good for a little more speed.