Twin 70 Evinrudes, how may primer bulbs?

[MovingTarget]

I have twin 70hp VRO Evinrudes on a Trophy 190. The port engine will idle well, but the starboard will only idle for about a minute (longer fuel line). There is 3 primer bulbs, one between the tank and "T" and one between each motor and the "T". They get soft, if I pump them the will idle better. I removed the bulb between fuel tank and "T" and installed a clear fuel filter. I could not get gas to flow into the clear fuel filter until I pumped the 2 bulbs together. So i think i need one before the "T" and that is it. Opinions???

Thanks!

 

[MovingTarget]

Re: Twin 70 Evinrudes, how may primer bulbs?

No Ideas?

 

[guy74]

Re: Twin 70 Evinrudes, how may primer bulbs?

Ok, I'll Bite First off, I have no experience with twin engines, but I think if the engines will run out fine then it isn't a fuel delivery problem. If the starboard engine dies after idling for about a minute, I would think it is probably loading up from carbs that need rebuilt. My 60hp, basically the same engine, used to load up and die after idling for a bit, but would run fine otherwise. The floats in the carbs were set too high, thus flooding the engine at idle. On the primer bulbs, I think you woul be fine with just one before the T, it would prime both engines. I personally would have two complete fuel systems, if I had twins on a boat. I realise that 2 tanks are probable out of the question, but 2seperate pickups, hoses, filters, bulbs would be nice for redundancy.

 

[watergecko]

Re: Twin 70 Evinrudes, how may primer bulbs?

I agree, if u have room for to tanks goto one tank/line per motor. Running through t's can stress a fuel pump.

 

[MovingTarget]

Re: Twin 70 Evinrudes, how may primer bulbs?

They run fine at WOT and every where but idle, so maybe it is not a fuel delivery issue, but it does not seem like there should be 3 primer bulbs. I would like to have the fuel delivery correct so I can trouble shoot the idle issues.

The starbord motor is also now running about 300-500 rpm less then than port at the same throttle setting.

It has a built in 41 gal ploy tank with only one pickup, not sure about adding another pick up. Not a lot of access to it.

 

[guy74]

Re: Twin 70 Evinrudes, how may primer bulbs?

Well, I guess you might have a dead cylinder on the starboard engine, you need to make sure it is running on all 3 cylinders. If it is running on 2 cylinders, it certainly would not idle well. Pull the plug wires one at a time to check if all cylinders make the same difference. I guess you need to do the basics, check compression and spark and go from there.