Yellow dot on Carb- What does it mean

[bdagold]

I have a 95 Seadoo Sportster and tring to find out what type of carb is on it. The person that I bought it from said that it was a 720 carb. I beleive that the motor is oringinal and is a 657. Not sure how to even check this. Please help......:ack:

 

[kustomkarl]

What are you trying to do? If you need a rebuild kit go to the "Parts" link at the top of the page to get a rebuild kit.

Karl

 

[bdagold]

Hello Karl, I am trying to figure out what size carb is on the 657X engine as the person that I bought the boat from told me that they were 720 carbs. Every time I fire up the engine and give a little throttle, it bogs down and cuts out. I have done a little research on the site and not sure what to do. Also the oil pump is disconnected and I assume that it is running on mixed gas. I am looking at setting the oil pump back up and have found on the site how to check to see if it is still pumping oil. Many Thanks Richard:ack:

 

[nswillin]

Look in your manual under "Technical Data." Then look under "CARBURETION" and it will list the Mikuni carb that you have.

Do not try to start this thing until you know for sure if it is running premix or not. There are test in your manual for the oil pump. Give us a shout if you have any problems. :cheers:

 

[kustomkarl]

Richard, also in the seadoo library is a manual on Mikuni carbs. So if you want to understand how they work it will enlightening you.
It might give you a better understanding of what is happening inside the carbs. The oil pump is good thing to have as it pumps oil to the engine at a variable rate. This allows it to be more efficient and less costly in the wrong run. Spark plugs will last longer too.

Glad to see you signed up for the Premium Membership. There is tons of information in the manual for you seadoo.

Let us know if you need any more help.

Karl

 

[bdagold]

Many Thanks for the information. It seems that the manual states they are BN 38-37 carbs. It is pouring down with rain today so will investigate some more tomorrow, if sunny. i am actually looking at pulling the motor out and replacing all of the gaskets. Do I have to remove the drive to get the motor out?:hurray:

 

[kustomkarl]

If the gaskets aren't bad or leaking I would leave them alone. I would check the compression and look for other things that need attention then making a huge project at the start. After you get it running you could figure what needs work and what to leave alone. Your manual should give you some insight as to what is involved to pulling the engine if you need to do it. You can leave the Jet Pump assembly in place and pull the engine. Keep track of the spacers thickness and location under the engine mount for replacement.

Karl

 

[bdagold]

Many Thanks Karl, I will do that and let you know how I make out. Great site. I placed a thread 720 carbs with a 650 core. No one answered. Can you delete it as my questions were answered here.

 

[Gunsrunner]

If you need to remove engine, when i do it i leave the mounts and shims bolted in place and remove the engine from the mounts. have done this a few times and haven't had to realign yet. If you do a pressure test on the motor and it holds pressure for 10secs then the gaskets are fine and you don't need to pull motor.
If you pull the carbies you can pull them apart and find what jets are being used.
Does then boat still have the grey fuel lines if so you need to replace them and clean the fuel system, baffle, selector switch, filters, screens in carbies, jets.