How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jason Your Own Question
Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 14304
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
44667847
Type Your Boat Question Here...
Jason is online now
A new question is answered every 9 seconds

I have a 1998 Yamaha 200, it starts fine idles file. But

Customer Question

I have a 1998 Yamaha 200, it starts fine idles file. But when you give it gas it floods out
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.

Hello my name is ***** ***** am I speaking with?

What is the model number on the engine?

When you say it floods out, what is the engine doing specifically to make you say that?

Customer: replied 1 year ago.
My name is***** don't have the model number at this time, but the engine kills when I give it gas
Expert:  Jason replied 1 year ago.

Hi Paul.

Is this engine a 2 stroke carb, 2 stroke EFI, 2 stroke HPDI? Or is it a 4 stroke?

Customer: replied 1 year ago.
Its a 2 stroke carb.
Expert:  Jason replied 1 year ago.

Got it. Now when you say it's flooding, is fuel pouring out of the front of the carbs?

Customer: replied 1 year ago.
No just the bottom one! I fixed that one, witch fixed the idling problem. Now, when I put it in gear & give it gas. If I give it gas real slow, it will go a little then it dies out
Expert:  Jason replied 1 year ago.

So the bottom carb is pouring fuel out?

Customer: replied 1 year ago.
Not anymore
Expert:  Jason replied 1 year ago.

What is the story on the engine? When did it last make full power? Has it been sitting a long time? How old is the fuel?

Customer: replied 1 year ago.
The engine had been set up about 2 years, the carbs have been rebuilt the motor has been freshened up. The gas is new
Expert:  Jason replied 1 year ago.

Has compression and spark output been checked? If yes, what are the compression numbers, and how specifically was spark output checked?

Customer: replied 1 year ago.
compression is 120! The spark was checked with new plugs & looked very strong to me
Expert:  Jason replied 1 year ago.

How was spark checked? Did you use an adjustable gap spark tool, or a timing light? Or did you just ground a plug out?

Customer: replied 1 year ago.
grounded the plug
Expert:  Jason replied 1 year ago.

Got it. That's not the correct way to do it. To check spark output you would need to use an adjustable gap spark tool, the tool needs to be set to 7/16ths of an inch. And spark must easily and consistanly jump that gap. I'm attaching 3 links below to youtube videos. This shows the correct way to do it.

https://www.youtube.com/watch?v=eSmNMWTDtZE&t=3m0s

https://www.youtube.com/watch?v=1y1X0V9wKx8

https://www.youtube.com/watch?v=EYKKtbbgO9U

Until that's done the correct way there is no way of knowing if the engine has good spark or not. Give those videos a watch. The spark test is either going to be a pass or fail. If it's a pass, the problem is still in the carburetion. If it's a fail, then the ignition system needs a deeper digging into in order to figure out why. Do you want to get your hands on a spark tester and get back to me?

Customer: replied 1 year ago.
I will look into it, but I don't think that is the problem
Expert:  Jason replied 1 year ago.

It definitely needs to be checked either way.

After that, the engine needs 3 things to run. Compression which you have. Spark which is unknown, and the proper ratio of fuel to air. You did say the carbs were rebuilt, but you didn't mention of they were rebuilt professionally by a certified Yamaha tech or not.

If spark is good. Then it's going to point to a fuel or sync issue. Sync meaning the carbs need to be properly synced to ignition timing. Or fuel meaning the carbs are still cogged.

When you say you don't think it's the problem. What is on your mind, what are you thinking?

Customer: replied 1 year ago.
I think its a fuel issue! And no a Yamaha tech did not rebuild the carbs, I did! That's why I'm thinking its a fuel issue. How do you go about making sure the carbs are synced?
Expert:  Jason replied 1 year ago.

There is a procedure in the service manual for syncing carbs and timing. If you can open up PDF files I'll be happy to give it to you. But I would need to know the exact model number on your engine, as they are all different.

Expert:  Jason replied 1 year ago.

There are no time limits here. Do you want to get tha tmodel number and get back to me?

Customer: replied 1 year ago.
Ok! I will get back with you.
Thanks
Expert:  Jason replied 1 year ago.

You are very welcome.

Related Boat Questions