Yamaha 4HP two-stroke problems

[root77]

Good morning



I'm new here, and I would like to find someone to help me repair my outboard engine - a Yamaha 4HP two-stroke engine.

I think it's a problem with the carburetor.

Do you know any outboard motor mechanic who can help ?

I live in Chigwell - Essex



thank you


JA

[User name]

Originally Posted by root77

Good morning



I'm new here, and I would like to find someone to help me repair my outboard engine - a Yamaha 4HP two-stroke engine.

I think it's a problem with the carburetor.

Do you know any outboard motor mechanic who can help ?

I live in Chigwell - Essex



thank you


JA

What are your symptoms? It's a fairly easy carb to work on. Anyone with some basic mechanical skills could clean and rebuild one of these.

[root77]

We went fishing and the engine started fine, but it was a bit sluggish after a few hundred meters, we stopped, and after this, I couldn't start again , we had to paddle back to the shore .

I have removed the carb but couldn't unscrew the main jet, there was no grip.

I have bought a new one from ebay (Chinese) - engine is starting but goes to very high RPM and I'm not able to control it .

I think I need help from someone who knows more about the outboards.

[User name]

Originally Posted by root77

We went fishing and the engine started fine, but it was a bit sluggish after a few hundred meters, we stopped, and after this, I couldn't start again , we had to paddle back to the shore .

I have removed the carb but couldn't unscrew the main jet, there was no grip.

I have bought a new one from ebay (Chinese) - engine is starting but goes to very high RPM and I'm not able to control it .

I think I need help from someone who knows more about the outboards.

There's a screw with a spring on it at the top of the throttle arm where the cable attaches and its for setting the idle speed. I'd back that off a little and see if it sorts your problem. If not then maybe give it to someone to fix.

I'd generally avoid the Chinese carbs though, since you can't be certain of the jet sizes or the quality of the carb itself. Some stuff is great but others are trash. It's difficult to know what you're getting.

You could take the carb alone to any decent marine/motorcycle mechanic in your area for a clean and reassembly. It's a very basic carb and they can be overhauled very easily.

[Fenlander]

>>>couldn't unscrew the main jet, there was no grip.

The main jet should have a screwdriver slot. When that is removed there will be another jet below, again with a slot for a screwdriver. Both these jets will be brass and are easy to damage. I'll often grind down a slightly larger screwdriver blade to make a perfect fit in the lower jet slot as it's easy to chew the brass away with an ill fitting blade.