Bayliner 3688 Speed Problems !! Need Help :)-gctid366764

[Guest]

HI !!

We bought a Bayliner 3688 , 215 Hinos, 1994, and found out now that the boat is to slow... ( i know iknow how you can buy a boat without seetrail ... but we get it from a friend very cheap and know the problem before. )

The boat is not coming into Plane, and at full thrust it goes only 9 knts. ( cause its not getting into Plane )

My friend get on the wrong mechanic and the mechanic sold him other Props cause with the old ones ( we think that these ones are the original ) the boat only made 2200 RPM. ( sure cause the boat is not getting into Plane... my thinking )

Now the boat makes 3000rpm but even its not getting into plane, and move only at 9-10knts.

My thinking is that the props now only makes higher Engine RPM but not get the Power to bring the boat into plane.

I ask them if they check the Trim Tabs, my friend told the mechanic does, but as im finding out now the Tabs moving in a very short way, dont know how far they have to move !?!

My thinking is now to put the old Props on it and checking the Tabs.

So the real Question is , anybody knows with what kind of props the 3688 original comes with ?, how far the trim tabs have to move down ? is the 3688 only equipped with 2 Tabs ? ( cause my 32 had 4 ! )

Whats the top speed of the 3688 ( i heard its much faster then the 3288 and the 3888 )

Anybody knows what else could be the Problem ?? ( also was thinking about the turbos, but how i could check it ? )

WOULD BE SOOOOOO NICE IF SOMEBODY COULD HELP !!!:worth

THANKS !!!!!!!!!!!!!!!!!!!!!

[smitty477]

Some data to work with please ....

- Did Boat ever plane?

- Current condition of boat bottom and running gear?

- Installed props are? (D X P X number of blades)

- Again , know props are not fouled?

- The engines are or are not known in tune?

- Your tachs are known accurate?

- Trim tab reserviour is full to line?

- Boat is reasonably weighed down?

Hope this helps

[Guest]

What is the condition of the bottom- clean or fouled?

Are the tachs accurate- are you sure the engines are actually getting to 3K rpms?

That should be an 18 knot boat, if not faster.

[Corky42]

Yea!!! I thought I was the only one out there with a 3688. Mine is a 92 and I can go all day at 2600-2700 rpm with speeds variable from 13.5 kts to 23kts depending on the currents in the San Juans. I will do some research and see what size props are on it. The survey showed two different sizes but we didn't notice anything weird.

Took it to Desolation last July and loaded fairly heavily ran a normal 15 kts.

I got 22kts on Lake Washington during the sea trial at top rpm.

She seems to be very comfortable at 2600-2700 kts.

Listen to the previous comments and make sure there isn't any salad growing on the bottom.

I am new to the bigger boat and deisels since I came from a 2452 which was a stellar performer. Certainly a learning curve.

Corky

[Corky42]

I checked the prop sizes on my 3688 and ther are: 4 blade 22X19.5 on the strbd and 4 blade 22X20 on the port.

I forgot to add to the speeds we experienced in Desolation. it was 15-17 kts not just 15 kts.

Hope this helps.

Corky

where are you located?

[Guest]

Weird- your props should be the same pitch....

[Guest]

I run 1/2" differnce between port and starboard I believe this practice is common with the Herth transmissions

[smitty477]

"Weird- your props should be the same pitch...."

"I run 1/2" differnce between port and starboard I believe this practice is common with the Herth transmissions "

Both statements are true but not all of the time - it depends on the exact transmission and its ratio.

On the Hurth and Twin Disc there is a plate on top of the trans which has data on it.

On the plate it will give you the ratio both forward and reverse for that transmission. (port and stb)

Currently on our HBW 800 series that ratio is the same at 1.96:1 both fwd and reverse.

In our case the props would be scanned and adjusted to the same picth.

But on many of these installs there is a slight difference between a fwd and reverse spinning trans and that would need to be compensated for in the props.

Hope this helps

[Guest]

Hello !! THX for all the answers !!!

SO, yesterday we brought the boat to another marina, before i treid to bring the tabs down and fill up the trim tab tank. and what happends boat comes into plane !! , but as we lowered the speed it didnt make it again. Oil reservoir is at same level... weird... could it be that the engine lose compression ? but then i gues it will not firing up immediatly. And i saw that the airfilters missing the filter stuff... so i was thinking about that the turbos maybe need a rebuild !?! ?! !?? , but why it goes on plane one time and then no more !?! !?

BUT I GOT ANOTHER QUESTION !! AND THATS A REALY STUPID ONE LOL , could someone tell me where the Stereo Radio is installed at the 36 ?? we cant find it , lol....

at the 32s and 38s its clear, but on this boat we only see the speakers .....

and something else , on the furniture inside, the beige laminat bandings from the doors and so on peeling off. Somebody knows where i can get them ??

Are they only 2 Bilge Pumps installed ? i only found one in front where the steps down to the galley and one in the enine room.

THHHHHXXXX!!!

[Guest]

and one mor quest :surr

somebody knows where i can get the plexi glas windshields on the Flybridge ?? all around cracked and they falling apart. Would be nice if somebody give me an adress or contact where i could order them.

THX !!!!

[kwb]

mogli007 wrote:
and one mor quest :surr

somebody knows where i can get the plexi glas windshields on the Flybridge ?? all around cracked and they falling apart. Would be nice if somebody give me an adress or contact where i could order them.

THX !!!!

Middy Marine - Redmond Wa..... Maybe. they were working on closing up shop and down to a few hours per day a couple months ago when I went and got a new section for mine.

[kwb]

mogli007 wrote:
HI !!

We bought a Bayliner 3688 , 215 Hinos, 1994, and found out now that the boat is to slow... ( i know iknow how you can buy a boat without seetrail ... but we get it from a friend very cheap and know the problem before. )

The boat is not coming into Plane, and at full thrust it goes only 9 knts. ( cause its not getting into Plane )

My friend get on the wrong mechanic and the mechanic sold him other Props cause with the old ones ( we think that these ones are the original ) the boat only made 2200 RPM. ( sure cause the boat is not getting into Plane... my thinking )

Now the boat makes 3000rpm but even its not getting into plane, and move only at 9-10knts.

My thinking is that the props now only makes higher Engine RPM but not get the Power to bring the boat into plane.

I ask them if they check the Trim Tabs, my friend told the mechanic does, but as im finding out now the Tabs moving in a very short way, dont know how far they have to move !?!

My thinking is now to put the old Props on it and checking the Tabs.

So the real Question is , anybody knows with what kind of props the 3688 original comes with ?, how far the trim tabs have to move down ? is the 3688 only equipped with 2 Tabs ? ( cause my 32 had 4 ! )

Whats the top speed of the 3688 ( i heard its much faster then the 3288 and the 3888 )

Anybody knows what else could be the Problem ?? ( also was thinking about the turbos, but how i could check it ? )

WOULD BE SOOOOOO NICE IF SOMEBODY COULD HELP !!!:worth

THANKS !!!!!!!!!!!!!!!!!!!!!

Assuming tachs are right(ish) - it sounds like you could be coming up on the governer as well as have the wrong props. What were the props that only turned up to 2200rpm?

The 32/38 had 4 trim tabs because the prop pockets and round chines didn't leave room for a properly sized single tab if the boat was going to operate at more than trawler speeds..... and keep in mind it was designed when fuel was expensive and they started with very small HP engines. As fuel prices (and interest rates) came down more power was added and some of the design comprimises that were made in terms of economy haunted the boats until replaced by more traditional V-hull forms (hard chines, no pockets) for planing and semi-planing hulls.

[jmcannonball]

When I got my 38, it only had two outboard trim tabs, my max speed was around 11-12 kts, I had a helluva whale-tail wake that stood about 3-4 feet high behind the boat, and I could not see over the bow. After I added another set of inboard tabs, my max speed increased to 14-15kts, the whale-tail wake practically disappeared, and I could see clearly over the bow. I also moved as much weight as possile to the front/bow of the boat to help keep the bow down. If you have Benett trim tabs, the existing pump can drive another set of tabs. Might be worth checking out.

[Guest]

Hello, afeter a long refited time,the boat is launh today . We installed the original Props. Its going worster. the boat makes no plane, ( trim tabs down sure ) , rpm no more the 2300.

The weird thing is half trotle we go to 2300 rpm , full trotle no more -nothing , feel like full trotle is the same as half..... . There is not much smoke ( one engine a little bit black but not much ) so i guess its not the turbo or ?? i feel a vibration every second for a half second on the starboard engine. Guess its the alignement but could also be an injector problem ! ?? tomorrow we will check the injectors. How we can find out if the turbos are ok ?? any suggest ?? WOULD BE GRATEFULL OF ANY HELP !!! THX ! Maybe someone could give me Earls Phone Nr ? or let him know my Problems ? THX !!!!

[Guest]

I have 1993 3688 with the same 210's in the V-drive configuration.

My performance is identical to what Corky indicated earlier. Stock props on mine are both 22 x 20.

There are only 2 bilge pumps installed, although the brochure specs say 3.

If you haven't yet found the stereo, it should be located near the top, inside of the 2nd set of glass cabinet doors, next to the battery switches.

Hope you get things sorted out