2-Stroke 1998 Yamaha GP760 Rebuild

[rossmi]

Hi, I bought a 760 that had a blown engine. I never rebuilt an engine so I wanted a project to learn on. I removed the engine and totally rebuilt it. New crank, piston, rings, etc. Got it all back to gether and installed. I have a couple of questions about the fuel system.

1. I assume the two lines are supply and return. On the carb there is a top and bottom nipple for the lines to connect to. Is the supply the top one?
2. I disconnected both lines. When I pump the primer I can't get any fuel?? I assume there should be some?? Also, when I turn the engine over should fuel be pumping through that line?? Every thing else seems to have came together fine, just can't get fuel to it.

Thanks so much in advance for any advice.

[tom_]

1. On the carbs there are arrow which show if it is an inlet or outlet, but top one should be outlet port.
2. How is the primer connected? What I know there is no primer originally on these, what kind of primer is this?

[rossmi]

1. On the carbs there are arrow which show if it is an inlet or outlet, but top one should be outlet port.
2. How is the primer connected? What I know there is no primer originally on these, what kind of primer is this?

So, I was wrong there is no fuel primer. There is a primer going to the oil tank. I guess it is to inject a little extra oil, if it was sitting or something like that???
Do you know how the fuel system works in this? Is there a sending unit or small pump?? I see where it leaves the tank and through the filter and to the carb....just wondering how it gets there. Thanks.

[WetTech]

So, I was wrong there is no fuel primer. There is a primer going to the oil tank. I guess it is to inject a little extra oil, if it was sitting or something like that???
Do you know how the fuel system works in this? Is there a sending unit or small pump?? I see where it leaves the tank and through the filter and to the carb....just wondering how it gets there. Thanks.

The fuel pump is built into the carbs. IF you want to add a primer, do NOT use a primer bulb like what is on outboard engines. Use something like this...https://www.amazon.com/DAPCO-Mikuni-...32762561&psc=1

Rebuild your carbs and triple check them. Only use original Mikuni kits.

[rossmi]

The fuel pump is built into the carbs. IF you want to add a primer, do NOT use a primer bulb like what is on outboard engines. Use something like this...https://www.amazon.com/DAPCO-Mikuni-...32762561&psc=1

Rebuild your carbs and triple check them. Only use original Mikuni kits.

Thanks so much for the reply. I did the carbs but might of did something wrong. If I disconnect the fuel lines from the carb should I feel suction from the carb???