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787 carb fuel line set up
- Thread starter porkncheese
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Here in the US we are almost mandated to use ethanol gasoline, there are a few exceptions. Ethanol breaks down the glue in the grey tempo fuel lines and causes a green goo to be distributed throughout the fuel system causing a lean condition which will literally burn up an engine. Therefore it is mandatory that we change out all of the fuel lines, most people including myself use black automotive type fuel lines.
I don't know about Australia, but if you all use ethanol in your gasoline you will also need to change out the fuel lines, clean the fuel system and at the minimum clean the carb. filters. Actually even if you don't use ethanol on an 18 year old ski it's not a bad ideal to do this. Here's a thread which has lots of information about the subject.
http://www.seadooforum.com/showthre...el-Delivery-Problems-low-revs-bogging-surging
Lou
Added:
I did notice in your second picture that the fuel lines are beginning to swell and are probably soft. If this is your ski the fuel lines definitely need to be replaced.
I don't know about Australia, but if you all use ethanol in your gasoline you will also need to change out the fuel lines, clean the fuel system and at the minimum clean the carb. filters. Actually even if you don't use ethanol on an 18 year old ski it's not a bad ideal to do this. Here's a thread which has lots of information about the subject.
http://www.seadooforum.com/showthre...el-Delivery-Problems-low-revs-bogging-surging
Lou
Added:
I did notice in your second picture that the fuel lines are beginning to swell and are probably soft. If this is your ski the fuel lines definitely need to be replaced.
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porkncheese
New Member
I changed my fuel lines but it wouldn't start when put in the new lines.
I tried everything. I cleaned and rebuilt the carbs and still the same.
So I called a mate to have a look. His a mechanic. He was saying that those hoses on the top of the carbs looked wrong.
I am convinced I put them how they where which is the same as the first diagram, black hoses.
Online we found pics showing both ways. These pics here are both from the internet.
When we changed the lines around to the way it is set up in the second picture it works and runs well. I was stunned.
Only problem is when I put in the water it runs like a pig. When I accelerate it bogs down badly.
Any suggestions???
I tried everything. I cleaned and rebuilt the carbs and still the same.
So I called a mate to have a look. His a mechanic. He was saying that those hoses on the top of the carbs looked wrong.
I am convinced I put them how they where which is the same as the first diagram, black hoses.
Online we found pics showing both ways. These pics here are both from the internet.
When we changed the lines around to the way it is set up in the second picture it works and runs well. I was stunned.
Only problem is when I put in the water it runs like a pig. When I accelerate it bogs down badly.
Any suggestions???
Well, the first picture looks correct. Did you change out the fuel control valve, personally I have not had much success cleaning them. Also when you rebuilt the carbs. did you use Mikuni kits?
Here's a picture of my spare set of carbs., I'm pretty sure they are set up the same as the first picture.
Lou
Here's a picture of my spare set of carbs., I'm pretty sure they are set up the same as the first picture.
Lou
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porkncheese
New Member
I didn't touch the fuel selector. I used Mikuni rebuild kits, made sure all gasket surfaces were clean, made sure all fuel passages were clear, etc.
How in the hell is it even running like that? Anyways like I said it seems to run great out of the water, its responsive and revs well. In the water its no good.
Mite just put those fuel lines back to how they were (1st picture), and see what happens.
Hey Lou what are those orange tubes that look to lead to jets up near the choke butterflies? Mine haven't got that
How in the hell is it even running like that? Anyways like I said it seems to run great out of the water, its responsive and revs well. In the water its no good.
Mite just put those fuel lines back to how they were (1st picture), and see what happens.
Hey Lou what are those orange tubes that look to lead to jets up near the choke butterflies? Mine haven't got that
Strizzo
Well-Known Member
Both pics appear to show the same thing. The line between the two carbs is the fuel feed for the pto carb, and the other that goes to the Y is the mag carb return line. The pto return comes out and connects to the other side of the Y.
Prokncheese, those lines are the accelerator pump lines.
Prokncheese, those lines are the accelerator pump lines.
You should at least clean the fuel selector valve, for testing you can just bypass it. Since it's running poorly in the water you may want to go back and start with the basics and check your compression, it should be in the 140-150psi range.
Sorry for the confusion with the second picture, this set of carbs. has an accelerator pump, I'll remove the picture.
Lou
Sorry for the confusion with the second picture, this set of carbs. has an accelerator pump, I'll remove the picture.
Lou
If you have the chokes removed and have a primer, you will need to open your high speed adjusters a little bit. Edit: reread, you were saying you didnt have an accel pump, not a choke.
I would do what Lou said and bypass the selector quick.
The other big question is did you replace the needle and seat in the carbs? Did you do a pop off test? The pop off isnt as important as making sure the N&S are sealing. If they leak off air, they will never run right.
I would do what Lou said and bypass the selector quick.
The other big question is did you replace the needle and seat in the carbs? Did you do a pop off test? The pop off isnt as important as making sure the N&S are sealing. If they leak off air, they will never run right.
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porkncheese
New Member
Strizzo, look closely at the pics because their not the same. The lines are crossed. Maybe it doesn't matter. Im not sure.
I do want to compression test it because it feels low.
Just have to borrow a compression test kit off one of my mates.
Thanks guys. I hope I get it going b4 the end of summer
I do want to compression test it because it feels low.
Just have to borrow a compression test kit off one of my mates.
Thanks guys. I hope I get it going b4 the end of summer
#1 is 100% correct. It would cause an issue most likely the other way. I am fairly sure with it crossed it would be trying to feed gas to the second carb via a tiny return fuel port. It would run, but not rev in the water.
Strizzo
Well-Known Member
Yeah you don't want them crossed, or you could probably starve the pto cylinder at high rpm.
porkncheese
New Member
Im in Tullamarine. Im taking it out to Pykes creek to test it on Friday.
porkncheese
New Member
Eildon hey. Its the worst when u drive that far only for something to let u down isn't it.
Paul
Paul
eildon !!
yep for sure , i have got it starting again , same deal , put some new fuel lines and a new select tap , but its 30+ for the next week and i have a beach lol
yep for sure , i have got it starting again , same deal , put some new fuel lines and a new select tap , but its 30+ for the next week and i have a beach lol
Jan> your description is classic leaky needle and seat, or the fuel tank vent isnt venting.
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