Engine/Electric problems

[g5665]

Hi there

I need some insight about a electrical (?) problem with my Y25.

Last weekend when I went out with it 2 fuses went out, one in the starter (10 Amp I think) and one in the engine (20 Amp). I replaced both, eventually was able to start the engine.
Yesterday went out with the boat again and the problem happened again. To start had to change both fuses and the one in the engine (20Amp) had to be bridged in order to make it work (was always burning). The result was that when I managed to make the engine start it came out some small amount of smoke from the alternator. After the engine started the smoke didn’t appear anymore. However, when we used the engine on the way back to the marina, the problem happened again and the engine (after 20 minutes working) just lost power and black smoke started to came out of the exhaust and also black water. I reduced speed and the water became clear again.
I will have a mechanic looking over it today but would like to know what may be wrong before the guys start to find new problems!!!
Is this an electric problem?
Mechanic?
All together?

Well… all insights are welcome!!!

Cheers

 

[Syntonos]

Double trouble

Sounds like you have two issues going. one easy fix, one going to cost $.

The good news--- your probably just running your little 8hp diesel to hard. The little engine that can , can only push the boat hull through the water at about 5kts max. Any more than that and the engine is overloaded and starts smoking and laying a film of black soot on the water. Slow down and enjoy the ride.

The bad news--- My first guess is a dead short to ground in your alternator. If your not strong in electrical diagosis find some one that is and have them check your battery charging system out. Chances are you'll need to replace the alternator.

Aren't boats fun!!

 

[g5665]

That's what i suspected also about the alternator...similar symptons like old cars when something goes wrong with the power generator.

As for the overwork... not really... with engine we barelly do more than 3knots... but we need to use it for at least 1 and half hour to leave and enter the marina. The access it's quite long and we not allowed to use sail power in the navigation channels (have alot of ferry and heavy cargo boats traffic, so the maritime police don't allow sailing).

I will go over the alternator this weekend... to check if it's dead... later will have a qualified engenieer to check the whole engine to see if something else more it's wrong.

Just worried with the fuses... because was the ones in the key starter and engine. Should this be a signal of something more serious?

Sounds like you have two issues going. one easy fix, one going to cost $.

The good news--- your probably just running your little 8hp diesel to hard. The little engine that can , can only push the boat hull through the water at about 5kts max. Any more than that and the engine is overloaded and starts smoking and laying a film of black soot on the water. Slow down and enjoy the ride.

The bad news--- My first guess is a dead short to ground in your alternator. If your not strong in electrical diagosis find some one that is and have them check your battery charging system out. Chances are you'll need to replace the alternator.

Aren't boats fun!!

 

[Syntonos]

Engine woes

Check the exhaust mixing elbow-- they tend to corode and clog up restricting exhast /cooling water flow. Be sure you have plenty of water coming out your exhaust. Water should be coming out in regular pulses.

 

[g5665]

Update on engine problems:
Today went to the boat and decided to clean it all with diesel following an advise of a friend (who had a Y25) that said it could be dirt and grease in the electric terminals (thats why it fumed and blow the fuses). Shooting in the dark here trying everything...
Anyhow, was washed and clean... drying now...
In fact the cables and connections were not that dirty... anyhow now its cleaner.
Tried to turn it on manually and it worked perfectly... just two turns and was on... however didn't engaged the gears...the water was clear in low speed and high speed. In high speed some smoke came out in the back with the water. Checked the oil, it's low, tomorrow will fill it with new one.
Same friend told me that the black fumes before could be due to something stuck in the propeller. So, tried to turn the shaft by hand near the stuffing box and it turned ok (don't know if too heavy or not but i didn’t had any problem turning it by hand). However will check on the weekend if something stuck in the propeller with the help of some friends standing on the bow.
Anymore clues about what should i check?
I didn’t tried to start it electric... will do tomorrow after letting it dry and after changing the fuses.
Today i let it work for 1 or 2 minutes and everything was ok... Alternator turning with no problems and seem to be charging bc the cabin lights were strong and got weaker when i turned off the engine (only on battery).




Picture:
Can see the fuse box (the fuse on it 20A it's burned) and the starter engine and the alternator. Before every time i use the starter, would make a spark in the connections of the starter. And last time it came out fumes from the alternator terminals.
On the bottom of the picture can see one (round) plug. They are two and one of them was disconnected before. Also, there is two cables (red and green) on the left side of the picture which i've no idea what they are (no place to connect them apparently)
Missing anything?

 

[g5665]

Good afternoon everyone

Just want to post the work I been doing in my Y25MKii…
Still running with problems with the engine/electric.
All the other work it’s done and ready to sail.

Today, as advised by some of you, checked the mixing elbow and the alternator. Both in good conditions!
Today the boat decided to start with electric start but I still have to bridge the fuse in the engine.
The 10A fuse in the start didn’t burn anymore but the 20A in the engine it’s always burning if not bridged.
The engine still run with black fumes when in high speed engaged. If not engaged no problem at all. Maybe have something stuck in the propeller (will check next time sailing).
However, want to solve the fuse burning in the engine before leaving port to check the propeller… In case something serious happen.
So, no battery problem, no alternator problem, no starter problem, no cable problem… What can it be that makes the 20A fuse blow???

I been waiting for a professional to come and see it… but I’m in “China” and it’s very complicated to convince one to came and check a small boat!!! So, he will, when he’s in the mood!!! Meanwhile I’ve to try to solve it!!

 

[g5665]

If you to choose:
Total yanmar ysm8 refit
New similar engine (8knots) made in China (I live in China) with 3 years warranty
New Yamaha 15hp outboard and inboard removed)

Which and why?

 

[Boffin]

The fuse for the starer may be underrate .The starter draw more than 20A while starting.

You have to replace the carbon brush in the starter and the alternator. I check the manual and let you know later.

 

[Boffin]

According to the manual :the starter can take up to 50 A , and you should use fuse at 50A or a bit more say 60A. In the original circuit diagram , there is no fuse on the stater wiring just like many other engine .

For the alternator it can generate 35 A at 5000rpm , you should use 30 or 40A fuse .

Good luck

KS Lam

 

[g5665]

The engine it's working already but still making some black fumes.
The mechanics are suppose to check the governor and the injection after the holidays.
Also i told them to replace the packing in the shaft bc the the shaft is getting to hot and i suspect that it's too tight
Lets see what will happen on Wednesday!!!
I just hope i can use the boat next weekend...been without sailing it for almost 3 months