Bucking problems

[Ottoman711]

Hi guys, I'm new.
Recently bought a 95 Baja blast with a Merc 120hp engine and I'm having some issues. Finally got it in the water and the boat wouldn't barely move. So I gave it more and it felt like a slipping clutch. It wasn't the engine causing this, could it be a bad seal on the propeller? Also I'm a bit confused about a line that spits water from the top of the engine down into the hole. I assume it's cooling the engine but where should it be spitting out?

 

[tdonoughue]

We should begin with the disclaimer: Never had a Baja and probably couldn't pick one out of a lineup.

That said, as to the not moving, frequently the slipping clutch you describe is cavitation (unless you have an actual clutch--which is possible I guess). Make sure the path to the impeller is smooth and the impeller is in good condition. Can you post pics of those? If there are holes/seams/screw heads in the path or if the propeller is eaten up, the cavitation that creates makes the propeller not 'bite'.

 

[Ottoman711]

Thanks for the reply. I do see a little bit of weeds but i don't think that's the issue.

 

[tdonoughue]

Actually, those weeds very well could be your problem. If I had that, my boat would be sluggish as all get out. Heck, if I have one little piece of string it acts up. Also, on mine, the screw heads at the leading edge of the grate are smoothed over with silicone.

Start with the weeds. Clear those out and see where you are.

 

[Ottoman711]

Iteresting. Now what about this cover, shouldn't it open when giving throttle?

 

[BigAbe75]

Iteresting. Now what about this cover, shouldn't it open when giving throttle?

Definitely, unless you’ve got 2 sticks like some have done. In which case, you could have 1 “shifter” for forward/reverse and another handle for throttle. But, on the standard Yamaha platform a single throttle handle controls direction and throttle.

 

[Ottoman711]

Just tested that and that's definitely a huge part of the issue. You can hear the cable move but the door barely opens if at all!

 

[tdonoughue]

Well, yes. That will do it as well.

 

[Ottoman711]

Now how to find the cable. This boat is like non existent to the web haha. Any idea about the hose spitting water tho? I posted a pic of it in the original post. I don't think it should be dumping inside the boat.

 

[Speedling]

Definitely, unless you’ve got 2 sticks like some have done. In which case, you could have 1 “shifter” for forward/reverse and another handle for throttle. But, on the standard Yamaha platform a single throttle handle controls direction and throttle.

My exciter had forward/reverse for each side and a throttle for each motor.
Check that all cables are working correctly and that it is opening fully when in forward.

 

[Gym]

Welcome to the forum @Ottoman711. If this is a " new to you boat" I would ALWAYS recommend changing spark plugs, oil & filter & check/change the air filter. If you have a changeable fuel filter or water/fuel separator change or service that also. I say this because small engines are greatly affected by most of these items.

When you say this is not an engine problem I assume you can run this up quickly through the RPMs (while on the trailer) without the engine stumbling? If that's the case I would agree with @tdonoughue that the water flow through your intake tunnel to your impeller is being disturbed causing cavitation. I also see what appears to be algae growth in the intake area and some caulking around the intake grate that looks loose. If that's the case these are all culprits.

With regard to the hole where water is coming out...That is your cooling water indicator. You should check it when running your engine on the hose or in the water. You should see water coming out at idle speed or something just above idle. If you don't see a flow of water it doesn't always mean no cooling water. It could just be plugged with debris, bugs or a kinked line.

Keep us updated as to what you find as this helps to educate the collective.

 

[Ottoman711]

Thanks everyone for the replies, the cable that opens the door I posted above was not working. I did some tinkering and adjusted it and it's working again. But should it fully open as soon as I start to throttle or should it open accordingly with the engine speed? I have it so it opens completely as soon as I throttle.
As for the water coming out of the hose, I was wondering where it should be exiting. This one literally dumps I side the boat.

 

[tdonoughue]

Well, inside the boat would be sub-optimal. Ours has a fitting in the hull and it goes out there.

As to the gate, ours goes up first (so nearly closed at neutral, then as you push throttle up the gate comes up, and a little farther the engine speed increases). Basically when you get the engine above idle the gate should be all the way up. I think. But remember, I was the one who could not pick your boat out of a line up.

Thanks for these pics! And posting. You note the lack of info on the web about your boat, but you are filling that hole now. Keep it up, please, and we will help as we can.

 

[Gym]

@tdonoughue is correct on both points. The first detent on your throttle will shift your thrust diverter fully open for forward, middle for idle and down for reverse. The rest of the travel on the throttle lever is strictly to increase RPM.

No water should be dumping into your boat. Is there a through hill fitting somewhere? That water should be going out somewhere visible to the operator. That's why it's a cooling system indicator.

 

[Ottoman711]

This is the only hole I saw right above it so maybe that's where it originally went but someone put a hose on it so the could have the hood open while running. Sorry for my impotants but if water runs out of that hose does it mean the engine is overheating?

 

[tdonoughue]

That could be it. Ours is an actual fitting. But I would stick the hose out that (especially if it goes all the way outside the boat).

No, water out of this indicates the cooling system is working. Basically they divert a part of the flow out of this, so you can see it is working. If there is no flow, there is no flow (maybe) in your cooling system (or not enough) and it needs to be investigated.

 

[Ottoman711]

Maybe I will make one out the back then, if I put it there it's going to soak us from spashing off the hood.

 

[Gym]

This is the only hole I saw right above it so maybe that's where it originally went but someone put a hose on it so the could have the hood open while running. Sorry for my impotants but if water runs out of that hose does it mean the engine is overheating?

No, as I mentioned earlier, the cooling water flowing out is only an indicator, to the operator, that cooling water IS flowing. If it's going into the bilge you would never see it.

 

[Ottoman711]

@Gym I can't change the oil, it's two sroke haha thanks everyone for the advice. Got everything set up, maybe give it another go tomorrow!

 

[Gym]

My advice was general advice for any pre owned boat. But, your correct, I did forget jetboat of your vintage are two stroke . Spark plugs are probably the biggest small engine issue though.