98 Bayliner with 135hp Mercruiser, tach broken?

[fabenarroyo]

Hi guys,

After taking my new baby to the lake for 2nd time, i found out 2 problems:

1st- It can reach 37mph but the tachometer only reaches 3300rpm, I was told, the engine should run as close as possible to 4800rpm on WOT. I know we need data, so, here we go: 98 bayliner 1850 capri with a 3.0l mercruiser alpha one, fully loader, 2 adults, 3 kids, 3/4 of the tank, cooler, towels etc. Prop: 17 pitch (which is the one that came from the
factory with).

2nd- After 20 minutes running and everything looking good, I started to feel a vibration in the wheel and a little louder engine sound, like the engine idling and running rough. Although it reached 34 mph (it got choppy in the afternoon, when I tested it again) i got the feeling that something is not working properly.

Please guys, give me some ideas of what should i look at. Thanks in advance!!

 

[Don S]

Re: 98 Bayliner with 135hp Mercruiser, tach broken?

If you put it in neutral and rev it up, will the tach show over 3300 rpm? Does the engine sound like it's going 3300 rpm instead of 4800 rpm?
You need to hook up a shop tach (maybe from a dwell meter or a digital timing light) and verify what the rpm actually is under load.

If the tach is actually correct, then you have an engine/drive problem of some sort.
Here is a list that shows what all can cause low WOT rpm.

http://forums.iboats.com/mercruiser...ives/list-possible-causes-low-wot-295070.html

 

[fabenarroyo]

Re: 98 Bayliner with 135hp Mercruiser, tach broken?

Thank you Don!

If my boat has any of the problems from that list (except bad tach or bad connections), do you think it would reach 37mph (tested by GPS)?
I'll try tomorrow to run it in neutral, I can't believe I didn't think about that! Thanks again!!

 

[Don S]

Re: 98 Bayliner with 135hp Mercruiser, tach broken?

It could if it normally reaches 45 mph.