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Does 580 with a Westcoast pipe need jetting?
- Thread starter IDoSeaDoo
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Dr Honda
Well-Known Member
Yes. But, since WestCoast has been out of Biz since the early 90's... unless you have the original install instructions... you are on your own.
Also... be warned. If it's an old engine... the pipe could bring death on faster. If it's been rebuilt recently... then it's not an issue as long as you don't run it lean.
Also... be warned. If it's an old engine... the pipe could bring death on faster. If it's been rebuilt recently... then it's not an issue as long as you don't run it lean.
Dr Honda
Well-Known Member
Mains are 125, and the pilots are 67.5
If you have a mid hesitation, I would go up to a 70 or 72.5 pilot, (depending on how bad the stumble is) and make sure your pop-off is on the low side of spec. About 22 to 23 psi. (Assuming you have the stock air box)
Also, open your high screws about a 1/4 turn.
That should smooth you out. (assuming the carbs are clean)
Oh... with the bigger pilots, you will turn in the low screws about 1/8th of a turn.
If you have a mid hesitation, I would go up to a 70 or 72.5 pilot, (depending on how bad the stumble is) and make sure your pop-off is on the low side of spec. About 22 to 23 psi. (Assuming you have the stock air box)
Also, open your high screws about a 1/4 turn.
That should smooth you out. (assuming the carbs are clean)
Oh... with the bigger pilots, you will turn in the low screws about 1/8th of a turn.
IDoSeaDoo
Well-Known Member
I upgraded the impeller to a Solas. When I hit the primer, the RPM's do tend to stay up (but I don't keep them there for long as I'm still in the break-in phase of my new rings). You don't think I should change the high speed jet to like a 127, just the Pilot? And no, I have a K&N air filter sitting on a ported riser, all new Genuine Mikuni internals. N/S has new seat, but old needle (ordered wrong needle). Stock seat size, with pop-off around 22psi. Should I lower it to compensate for the aftermarket air filter?
Lowering pop off to adjust for that flame arrestor is for a "just off idle" hesitation. The Dr. was right to move your jets up a little and with the HS needle(s) at 1/4 it's gonna be plenty of fuel. Back then Westcoast had the contract for making Seadoo's pipes. The aftermarket pipes were a prelude to the upcoming models. Be sure not to lower pop off until you try his larger low speed jets cause that should be plenty.
Yes, he's right to tell you to up the high speed jets. The reason for this is that your leanest spot is 80 percent throttle. Opening your high speed needles will affect 80%-WOT. Of coarse theres a little overlap throughout. He was trying to target your lean spot. Did you try turning out your needles? But if the pipe is doing it's job as a performance add-on then it should be asking for more fuel. Is it louder? If so then you got flame arrestors letting air right in and the pipe letting air right out. DR. Honda was correct, put some more fuel with that.
Dr Honda
Well-Known Member
All of your jets will effect "Overall fuel" in the system. So, more pilot fuel will carry over to the high speed section.
Since you cant get from mid, to high RPM... that means you need more fuel in the pilot system. Basically, since you can't get into your "High" speed system.... there is no reason to change the high speed jets. (yet) When you tune a carb, there is no fast way to do it. You will need to have them a part a few times, and you don't want to change too much at one time. The nice thing with the high speed system, is that you can add more fuel with the high needle.
I can tell you right now that your dead spot is because of the filters, and not the new pipe. When you ask us for tuning help, you have to tell us EVERYTHING you have changed. I hate aftermarket filters as then can be a bastard to make run properly. Not to mention... if yo have the big plastic air box... it can support +130 HP without an issue.
As above... I wouldn't go too low on the pop-off, or you may have low RPM issues. BUT... I may get it between 20 to 22 psi.
Finally, when you get the carbs apart again... make sure that the check valve in front of the high speed jet is in good condition, and make sure that all the transition ports are clear. Use spray carb cleaner at the jet, and make sure you can see it coming out all the ports. Also, I would recommend using cleaner, and compressed air a few times just to make sure they are totally open.
Since you cant get from mid, to high RPM... that means you need more fuel in the pilot system. Basically, since you can't get into your "High" speed system.... there is no reason to change the high speed jets. (yet) When you tune a carb, there is no fast way to do it. You will need to have them a part a few times, and you don't want to change too much at one time. The nice thing with the high speed system, is that you can add more fuel with the high needle.
I can tell you right now that your dead spot is because of the filters, and not the new pipe. When you ask us for tuning help, you have to tell us EVERYTHING you have changed. I hate aftermarket filters as then can be a bastard to make run properly. Not to mention... if yo have the big plastic air box... it can support +130 HP without an issue.
As above... I wouldn't go too low on the pop-off, or you may have low RPM issues. BUT... I may get it between 20 to 22 psi.
Finally, when you get the carbs apart again... make sure that the check valve in front of the high speed jet is in good condition, and make sure that all the transition ports are clear. Use spray carb cleaner at the jet, and make sure you can see it coming out all the ports. Also, I would recommend using cleaner, and compressed air a few times just to make sure they are totally open.
Efficient? you gotta throw that out the window when you start modding. The question is "does it run better than stock?" And a properly running stock ski is pretty darn good. I say if you have no hesitation or soupy spots in any of the throttle range posistions and your wot plug test look good, then enjoy. I invested in a tto tach and a Garmin E-tech GPS so now I can see what mod does what and make shure I end up with some sort of advantage.
IDoSeaDoo
Well-Known Member
Okay, so I rejetted the main from 67.5 to a 70. I also replaced the N/S with new 2.0 one and lowered the Pop-off to about 19 or 20 (from 25 psi). It runs considerably better, but it still seems to accelerate slower than I expect. Am I just expecting too much from a puny 580 or is the mixture not right now? How do I know if it's too rich/lean in the middle range?
I think it's still a bit lean at WOT as squirting more fuel into the carb w/ primer makes rpms rise just a bit.
I think it's still a bit lean at WOT as squirting more fuel into the carb w/ primer makes rpms rise just a bit.
Dr Honda
Well-Known Member
Then, yes... you are still lean up top. I would open your high needles a 1/2 turn more, and try it.
As far "How do I know if it's too rich/lean in the middle range?"... that's where tuning experience comes in, and that's kind of why I recommend not taking on a project like this without the original install instructions. Learning to properly tune, and jet takes a long time... and unfortunately, you will probably loose an engine along the way, if you try to teach yourself.
Personally... I would remove the K&N filters. They aren't doing anything for you, and they make tuning harder. Also... they offer ZERO protection for water ingestion if you roll over.
Now... as far as "Am I just expecting too much from a puny 580?" Yes you are. Assuming it was in perfect running order... it was only a 55~60 hp engine. The pipe, properly tuned will give you an extra 10 hp. (maybe 15) So... you can't expect it to run with a stock 720 or 800 ski.
My personal Si... I worked the engine over, and I got it to run into the low 40's... and that was fun with that ski... but it's a far cry from almost 60 mph with a stock 800 XP.
As far "How do I know if it's too rich/lean in the middle range?"... that's where tuning experience comes in, and that's kind of why I recommend not taking on a project like this without the original install instructions. Learning to properly tune, and jet takes a long time... and unfortunately, you will probably loose an engine along the way, if you try to teach yourself.
Personally... I would remove the K&N filters. They aren't doing anything for you, and they make tuning harder. Also... they offer ZERO protection for water ingestion if you roll over.
Now... as far as "Am I just expecting too much from a puny 580?" Yes you are. Assuming it was in perfect running order... it was only a 55~60 hp engine. The pipe, properly tuned will give you an extra 10 hp. (maybe 15) So... you can't expect it to run with a stock 720 or 800 ski.
My personal Si... I worked the engine over, and I got it to run into the low 40's... and that was fun with that ski... but it's a far cry from almost 60 mph with a stock 800 XP.
Dr Honda
Well-Known Member
At this point no. You can simply open the high needles to add fuel If you need them open more than 1 turn to make it run right... then you go back and put in bigger mains, and close the high needles back down.
You can... but it's not needed. (and hard to read) I recommend riding around at about 1/4 throttle for a minute or two... then pop it open to full. If it sputters, and stumbles... it's rich. If if feels flat, or dies... it's lean.
Where there is too much fuel, and it won't go. (and clear out) In a properly running ski... this is normally felt when it's cold. You start it with a choke, or primer... then idle out, and when you open the throttle the first time... it will stutter, and then clear out, and run smooth. Once warmed up, that should no longer happen. If it does, your low needle needs closed a little.
IDoSeaDoo
Well-Known Member
Well, I made it out to the lake this weekend and played with the tuning (a lot). I put in the low jet with the 70, and 127.5 on the high jet. This worked okay, but it still felt like it was cutting out before it would reach top speed. Like from half throttle to full still felt lean and hesitant. The backfires at WOT finally convinced me to install the 130 jet. The 130 with about .5 turns out on the high made it run seemingly well on at full throttle, however I still have a disturbing problem:
At all throttle positions, the ski has this thing where it feels like it won't maintain RPMs. It seems to fluctuate a little, as if it wants to run "stronger", but something is preventing it. Even at 80-100% throttle, where it feels like it runs best, it still does this. I did check to make sure I didn't have air leaks in my pickup line by plugging a new hose on my carb and sticking the other end into a gas can and riding it. Anyone have this before?
At all throttle positions, the ski has this thing where it feels like it won't maintain RPMs. It seems to fluctuate a little, as if it wants to run "stronger", but something is preventing it. Even at 80-100% throttle, where it feels like it runs best, it still does this. I did check to make sure I didn't have air leaks in my pickup line by plugging a new hose on my carb and sticking the other end into a gas can and riding it. Anyone have this before?
IDoSeaDoo
Well-Known Member
BTW the plug test is inconclusive. I bought new NGK's but the bottom of the rim has a variation of color. Right by the electrode, there is a black chunk of carbon, but in other parts of the rim, it's still shiny. There seem to be smudges on the rim that I can wipe off down to new metal. Not sure how to read this. The motor itself feels rather HOT! i can put my hand on it, but not for very long. The overheat buzzer has never come on.
Dr Honda
Well-Known Member
That surging you are feeling is an indication of a supply issue. Your pump may not be happy (internal of the carb) or there is still an air leak in the feed end. I know you said you went directly to a fuel can... but the leak could be at the fitting, at the carb.
Since it's surging in the low to mid RPM's more... then I would say to you need to go up one more pilot size. (They go 2.5 at a time) AND... veryify your pop-off. It may be a little high for the aftermarket filters. This is exactly the kind of tuning issues you can get with aftermarket filters.
Since it's surging in the low to mid RPM's more... then I would say to you need to go up one more pilot size. (They go 2.5 at a time) AND... veryify your pop-off. It may be a little high for the aftermarket filters. This is exactly the kind of tuning issues you can get with aftermarket filters.
IDoSeaDoo
Well-Known Member
Well, I took the ski out on Monday, and I felt like it ran great at 80% throttle. I haven't changed anything, but didn't notice any surging (at 80%). Any wider though, and I felt like it lost a bit of power. Also, at the lower throttle position (30-70%) there still exists this weird surging. I can't tell if it's hesitating or getting too much fuel. Is there anyone in the North Carolina triangle area that wouldn't mind coming out to give me a hint? I'll buy you drinks, dinner, w/e you want 
I'm always down to meet a die hard seadoo fan like me.
I'm always down to meet a die hard seadoo fan like me.
Dr Honda
Well-Known Member
For the low/mid: If it's too much fuel... it will be sputtering. (feels like an ignition miss) If it's surging, but is running smooth... that's a lean condition.
For the high: if 80% throttle is max power (by feel) you are lean up top. Can be supply or jetting.
Since I'm seeing 2 possible lean conditions... BE VERY CAREFUL !! this is exactly how people burn out engines. This will be the last time I will say this, since I don't want to sound like I'm preaching... but get rid of the aftermarket filters !!!! They completely change the vacuum signal in the carbs... and make it very hard to tune. The stock black air box is good to about 130~140 hp SO... I don't think it will take anything away from your engine/pipe combo.
Once you get it running right... then you can put the filters back on, and start tuning again.
Last thing... do you have the water in the pipe set right? The water int he pipe makes a big difference in the tuning.
For the high: if 80% throttle is max power (by feel) you are lean up top. Can be supply or jetting.
Since I'm seeing 2 possible lean conditions... BE VERY CAREFUL !! this is exactly how people burn out engines. This will be the last time I will say this, since I don't want to sound like I'm preaching... but get rid of the aftermarket filters !!!! They completely change the vacuum signal in the carbs... and make it very hard to tune. The stock black air box is good to about 130~140 hp SO... I don't think it will take anything away from your engine/pipe combo.
Once you get it running right... then you can put the filters back on, and start tuning again.
Last thing... do you have the water in the pipe set right? The water int he pipe makes a big difference in the tuning.
IDoSeaDoo
Well-Known Member
Doc, you have convinced me, my next step will be to put the old intake back on. I took my flame arrestor apart and removed some of the screens, should I re-insert them back in?
As far as the pipe goes, I have it hooked up like stock, with the exception that I took one of the outlet lines (that pee off the back of the boat) and plugged it into the outlet stinger, just before the rubber flex hose. I could not find any other diagrams as to how to hook up the water and do not have water injection for this ski. I think there is another port on the pipe that has just a pipe plug in it... but again, I'm not sure what to do with it. I was hoping the answers would precipitate through the grape-vine after I got the pipe.
As far as the pipe goes, I have it hooked up like stock, with the exception that I took one of the outlet lines (that pee off the back of the boat) and plugged it into the outlet stinger, just before the rubber flex hose. I could not find any other diagrams as to how to hook up the water and do not have water injection for this ski. I think there is another port on the pipe that has just a pipe plug in it... but again, I'm not sure what to do with it. I was hoping the answers would precipitate through the grape-vine after I got the pipe.
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