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2000 30 hp 4-stroke issues?

J

Jedrow

New member
I just picked up a 14' Lowe with a 2000 30-HP 4-Stroke Merc.
When i first ran it, it ran like junk.....found water in the tank....great.
So i cleaned out the tank, cleaned the line and filter, and cleaned the carbs (thats a crappy job), and changed all the plugs & oil.
Now it runs ok but it doesnt like full throttle from an idle......it just boggs. Now this being said, if you ramp the throttle up slowly, she runs like a champ.
Since the seller was my neighbour, he took the motor to our local mechanic to get it fixed on his dime.
Well the mechanic can't figure it out either but told me that it had low compression.....which i believed was bull.
I checked the compression myself 100 to 105 PSI on each cylinder.

Does anyone know what the compression should be on a 30 4-stroke?
Anyone have any insight into why I might be getting a bog at full-pin?

Thanks in advance
 
Re: 30-hp 4-stroke issues?

Is that the three carb motor. There are a couple things with those carbs there is a passage in the float bowl that you cannot clean you can try and try and carb cleaner will not clean it. You can get some Tohatsu engine cleaner or Mercs version of it and leave the float bowls soak in the stuff for a couple hours but it is cheaper and faster to change the float bowls, you can order them from a Tohastu dealer for far less than a Merc dealer.

Second there are three little plugs in the intake manifold aft of the carbs, There is a vacuum guage tool that screws into all three of those at the same time to allow you to synchronize the carbs on the low side, this is a tohatsu service tool not sure if Merc had it as well.

If you are trying to accelerate like a two stroke - That motor will not do that and it will always fall on it's face and bog, you need to feed the throttle in medium slow and they idle at 1200.

Hope those give you some ideas.
 
Re: 30-hp 4-stroke issues?

Thanks for the insight Crankbearing. I still have a feeling its carb related....gonna pull them off again and check for a second time.

Still interested in what the compression should be?

Cheers
 
Re: 30-hp 4-stroke issues?

Yes it is carb related for sure The other thing I should have mentioned is you MUST have a water separator. I did a 25 yesterday, stalling, hesitating bogging but idles fine. The carb (1) is the same as the three on yours. Took the float bowl off and it was GREEN inside. All the jets were plugged solid with green goo. I will check the book for compression values.

If you are gonna tackle the carbs then take one apart at a time there are lots of small pieces in there and there are two jets in the center of the float bowl, one visibile and one under the rubber plug. I can get you the Tohatsu part number for the carb kits if you like. They are a complete kit for all three carbs and include screws, floats and needles etc and a can of engine tuner to soak em in carb cleaner will not do it at least not the aerosol kind.

No water sep, no fuel treatment. Soaked the carb in Engine tuner for an hour, reeemed the jets and put a kit in it installed a w/s kit and put some sta-bil in the fuel. Runs like a champ now but still has a slight lag on idle to full throttle hard accel.
 
Last edited:
Re: 30-hp 4-stroke issues?

Jedrow said:
I just picked up a 14' Lowe with a 2000 30-HP 4-Stroke Merc.
When i first ran it, it ran like junk.....found water in the tank....great.
So i cleaned out the tank, cleaned the line and filter, and cleaned the carbs (thats a crappy job), and changed all the plugs & oil.
Now it runs ok but it doesnt like full throttle from an idle......it just boggs. Now this being said, if you ramp the throttle up slowly, she runs like a champ.
Since the seller was my neighbour, he took the motor to our local mechanic to get it fixed on his dime.
Well the mechanic can't figure it out either but told me that it had low compression.....which i believed was bull.
I checked the compression myself 100 to 105 PSI on each cylinder.

Does anyone know what the compression should be on a 30 4-stroke?
Anyone have any insight into why I might be getting a bog at full-pin?

Thanks in advance
Click to expand...

I have the same engine and had the same problem. Take your carbs apart and clean out jets etc with carb cleaner. Now here's where your problem is. The float bowls have 2 passages that are plugged. Take out the pump and spring(one small screw holding them in) there is a passage that goes through the bowl casting from the pump and another one in the middle of the bowl that goes to the primary. These two passages are plugged for sure. I know I had the same issue and it took me a week and had to pull the carbs 3 times to figure this out. Put some carb cleaner in the bowl( enough to cover passages and let it soak for 15 minutes, then take a bread twist tie (wire only) and slowly clean the passages out. Spray and clean these out until you can shoot carb cleaner through them. You will not believe what crud comes out of these. Take your time and make sure you have these cleaned really good. If you have an air compressor and a rubber tipped nozzle it makes things much easier also. I did this and my engine purrs like a kitten and will go from idle to full throttle without hesitation. So basically what you have is your primaries are plugged and you have to feather the throttle to get it past the primaries, then when you get to your secondaries it runs fine. Let me know how it turns out! P.S. your compression new should be 115 new but anything over 100 is fine.
CF
 
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