Project Doos

[needforspeed]

Ok, as some of you have been following my project posts, I am finaly done and was riding them on sat. I restored two SeaDoos a 1989sp and a 1990 sp. I took them both out for the break in on sat. They both ran well. At the end of the day when I got back to the ramp, my 89 sp died. couldn't get it started again. When I got home, I noticed my fuel valve was shut off. Now I had my 6 year old daughter on my ski with me and as any 6 year old will do she wanted to push buttons and turn knobs. Before I realized the knob was shut off, I started messing with my mixture screws on the carb. Then I realized the fuel knob was shut off. So I put everything back to where it was which was L/S screw to 1 1/2 turns and the H/S to 0 changed plugs as I thought that maybe with pre mixing and extra break in oil that it was a very good probability that I had fouled the plugs. Turned the fuel back on and it fired right up and idled nice. So I go back to the ramp to put it back in and make sure it was good to go. It fires on the trailer. I shut it off and put it in the water and it won't start. Mess around a little more and it finally starts and runs good then just died and I had to start it up and swim it back to the ramp (about a 1/4 mile). I get it home and it fires right off and idles great on the hose. So now I think it is good to go as I tried it several times and it fires right up and idles great. Now Sunday I go out again, once again at the ramp I fire it up to make sure it is going to run. Fires right off. I put it in the water it starts and then shuts down and won't fire. I start checking everything, Pulse tube, fuel lines, fuel filter looking for leaks....Finally I find a cacoon like substance in the fuel tank vent. Now I try to start it and the battery is dead from all the cranking trying to get it started. This may have been the problem. But it was there all day sat and the thing ran maybe during the riding sat it pushed/ pulled the cacoon until it got bunched up till it was trotally clogged? My question is this: if you were having venting issues, could it damage the fuel pump on a 38 super BN mikuni carb? Why would it run out of the water and have problems in the water? The carbs have been rebuilt with pop off within the propper specs. It ran good for a day and now it is crapping out on me...I didn't even get to run a whole tank of fuel through this thing yet. The 90 sp has been set up exactly the same way and it is running flawlessly. Starts right up idles great and has nice throttle response. It is really baffling me. The only thing I can think of is rotary valve cover clearence might be too much. It is 20 years old after all. But I want to eliminate all possabilities before I got to take that off to get another. Any ideas or input would surely help...Thank in advance:willy_nilly:

 

[Dr Honda]

If the tank wasn't venting... then when you build a vacuum, it will stop running. As far as damaging the pump... nope... not a chance. It's a diaphragm pump, with rubber or plastic valves. It will safely pass anything that can fit in it... and it just won't pump if it's plugged up.

I would think you have an air leak in the fuel valve, or the pick-up tubes, in the tank are plugged.

Just thinking out loud here. Did it sputter, and die, or did it just shut off? If it just shut off... it's an electrical problem. It could be a second bad rev-limiter, or kill switch.

 

[needforspeed]

If the tank wasn't venting... then when you build a vacuum, it will stop running. As far as damaging the pump... nope... not a chance. It's a diaphragm pump, with rubber or plastic valves. It will safely pass anything that can fit in it... and it just won't pump if it's plugged up.

I would think you have an air leak in the fuel valve, or the pick-up tubes, in the tank are plugged.

Just thinking out loud here. Did it sputter, and die, or did it just shut off? If it just shut off... it's an electrical problem. It could be a second bad rev-limiter, or kill switch.

It sputtered and died. It didn't want to idle most of the day..I just figured I would adjust the idle later as my daughter was riding with me and it would have been a huge PITA to get her off and lift the seat and all that jazz. I was also figuring with the added oil and all the no wake zones we were in that maybe the pluggs were fouling. So when we were approaching the ramp it just king of sputtered and quit. Then it restarted and sputtered and quit. Then wouldn't restart.

Oh, the plugs are a nice carbon color looks like it was running rich but that is to be expected due to the extra break in oil. But they look awfully dry. If that makes sense. That is why I think it is a fuel delivery problem.

 

[Dr Honda]

Dark and dry is OK. Dark is from the extra oil. dry is because it wasn't too rich. (fuel) In a 4-stroke engine... oil fouled is from crank case oil... and it doesn't burn too good. If you have wet oil fouled plugs in a 2-stroke... something is very wrong... or you mixed it up at 20:1. (way too much oil)

From what you are saying... yep... it's a fuel problem. I would just double check everything. Pull off each hose, and make sure they are clear. Make sure the O-ring on the fuel bowl is good, and check the filter in the carb. (may be plugged)

FYI... after this weekend, I leaned out my low needed to 1-1/4 turns out. (If you are using my jetting for an SBN on a yellow engine)

 

[needforspeed]

Dark and dry is OK. Dark is from the extra oil. dry is because it wasn't too rich. (fuel) In a 4-stroke engine... oil fouled is from crank case oil... and it doesn't burn too good. If you have wet oil fouled plugs in a 2-stroke... something is very wrong... or you mixed it up at 20:1. (way too much oil)

From what you are saying... yep... it's a fuel problem. I would just double check everything. Pull off each hose, and make sure they are clear. Make sure the O-ring on the fuel bowl is good, and check the filter in the carb. (may be plugged)

FYI... after this weekend, I leaned out my low needed to 1-1/4 turns out. (If you are using my jetting for an SBN on a yellow engine)

As a matter of fact I am using your settings. But the other one is running perfect. It is idling kind of high and when I slowed down the idle it was kind of vibrating pretty rough so I found a happy medium. I put the trickle charger on the other one (problem ski) and it took two days to get it charged back up. So I haven't tried it again since I unclogged the vent line. Maybe after work today . I am thinking of bringing them to the shop to get them dialed in to 100 % so I don't have to keep messing with them. I have done all the major expensive chit so I figure it couldn't be to bad to just get a trained pro to dial them in so they are reliable. I hate to do it after doing everything else by myself but if I want them to be done for my vacation then I need to do it. I am running out of time and I still have to get the boat ready for vacation. 1989 22' Sea Ray Pachanga with a 454 that was sent out to a boat racing place and blueprinted and mild cam. 70 MPH boat. It is a whole lot of fun on the lake.

 

[needforspeed]

If the tank wasn't venting... then when you build a vacuum, it will stop running. As far as damaging the pump... nope... not a chance. It's a diaphragm pump, with rubber or plastic valves. It will safely pass anything that can fit in it... and it just won't pump if it's plugged up.

I would think you have an air leak in the fuel valve, or the pick-up tubes, in the tank are plugged.

Just thinking out loud here. Did it sputter, and die, or did it just shut off? If it just shut off... it's an electrical problem. It could be a second bad rev-limiter, or kill switch.

Well when building my pop off tester I hooked it up to the pulse line and pumped it up to maybe 10-12 lbs. to see if the tester was holding air. Then AFTER I read the pop off procedure and fuel pump test procedure it said to pump the fuel pump to 4 psi not over or it could damage the diaghram. That is why I thought mayb I messed something up. But what is throwing me off is that is ran all day sat.

 

[Dr Honda]

The pump diaphragm is kind of rigid. If you popped it... you would know. But, doesn't hurt to check.


One thing... I really would think twice before taking it to a "Pro." First... this is the peak of summer, and they may tell you it will be 3 weeks before they can look at it. Second... they don't like to spend much time troubleshooting a problem. (they may do it half ass'ed) and third, they may start it on the trailer, and say... "It's fine."

I can't tell you how many times on this board Ive seen posts where the mechanic said it was "good to go" but then when it hit the water... it wouldn't go. Mechanics don't have time to test ride your ski, and most shops don't have the proper test tanks because the EPA regulates them. (oil in the water)

I spent 8 years in college, and I now turn a wench because I don't trust people. Shops like mine, or snipe... or Chester's are few, and far in between.

You are better off doing it yourself. (or taking one ski on vacation)

If you were closer... I'd help you out.

 

[needforspeed]

took it out after work today

I wasn't going to but I walked by and pushed the button and it fired right up. I put it on the hose and it ran good. I drag it to the ramp and it fired right up in the water on the trailer for like 10 minutes al through the RPM range. So I think ok I am going for a ride. I shut it down, take it off the trailer, park the truck put on my life vest and it won't start.........Finally I get it started. I take it for a ride it idles ok and whe I give give it gas it kind of bogs..but if I feather the throttle it gets right up on plane up till about half throttle. On a hunch (because I am suspecting the fuel pump) I give it a shot from the primer and she leaps out of the water( I was holding the throttle 3/4 open when I gave it the primer shot. So it I am thinking it is a fuel delivery problem. I have two fuel filters before the carb a see thru one and a sealed closed automobile type (white plastic) the see thru one is before the one I can't see. I have a new fuel selecter valve and all new fuel lines and I am running the marine Stabil in my premix. I am pretty sure the carb filter (which is also new) is clean as that is the last one in the line. It surges like it is running out of fuel I hit the primer and she gets right up and goes.

 

[needforspeed]

Pop off pressure is between 26 & 28 psi

Dr. Honda, Do you think my pop off pressure is too high? Would that cause some of my issues?

 

[Dr Honda]

28 psi on a super BN should be fine... BUT... what size needle and seat?


Honestly... it sounds like your check valve is leaking, or you have a partly plugged main jet.

I would take that carb apart again, and verify every passage is clear. I can't tell you how many carbs I've done over the years... but on more than one occasion, I have missed things. I remember a Yamaha XT350 back in the 90's that I had the carbs off of it 4 times before I found the plug. It wound up being a clogged pilot air passage. I could get cleaner thought it (I could see it bubble) but it was half plugged. And since it was an air passege... it would effect the mid throttle. I finally got desperate, and did something that you shouldn't do. I used fine stainless gauge wire... and pushed it thought the passages.


BUT... that's why I test ride stuff before giving it back.

 

[needforspeed]

28 psi on a super BN should be fine... BUT... what size needle and seat?


Honestly... it sounds like your check valve is leaking, or you have a partly plugged main jet.

I would take that carb apart again, and verify every passage is clear. I can't tell you how many carbs I've done over the years... but on more than one occasion, I have missed things. I remember a Yamaha XT350 back in the 90's that I had the carbs off of it 4 times before I found the plug. It wound up being a clogged pilot air passage. I could get cleaner thought it (I could see it bubble) but it was half plugged. And since it was an air passege... it would effect the mid throttle. I finally got desperate, and did something that you shouldn't do. I used fine stainless gauge wire... and pushed it thought the passages.


BUT... that's why I test ride stuff before giving it back.

N/S is a 2.0 It was a new check valve when I rebuilt the carb but it could be bad and I could have a clogged jet. It is such a PITA to get that carb on and off that I was trying to eliminate everything before I had to remove the carb. I think it ran ok on Sat because I didn't really get on the throttle due to:
1.) My daughter was on the ski with me.
2.) I was taking it easy for break in so maybe it was actually running pretty bad the whole day but I never got it to the point of the problem.
But I am pretty happy it isn't anything really ball busting like the spark again. I have now narrowed it down to a fuel delivery problem weather carb or fuel pump.

 

[needforspeed]

The pump diaphragm is kind of rigid. If you popped it... you would know. But, doesn't hurt to check.


One thing... I really would think twice before taking it to a "Pro." First... this is the peak of summer, and they may tell you it will be 3 weeks before they can look at it. Second... they don't like to spend much time troubleshooting a problem. (they may do it half ass'ed) and third, they may start it on the trailer, and say... "It's fine."

I can't tell you how many times on this board Ive seen posts where the mechanic said it was "good to go" but then when it hit the water... it wouldn't go. Mechanics don't have time to test ride your ski, and most shops don't have the proper test tanks because the EPA regulates them. (oil in the water)

I spent 8 years in college, and I now turn a wench because I don't trust people. Shops like mine, or snipe... or Chester's are few, and far in between.

You are better off doing it yourself. (or taking one ski on vacation)

If you were closer... I'd help you out.

This guy lives near the water and test rides everything before he gives them back. He was refferred to me by a friend. I just don't have the time to mess with it anymore. I figured I did all the hard stuff the rest is pretty easy and should not be too expensive. Now I could be wrong too. This guy has a shop out of his house so there is no overhead. He races skis and services them so I am hoping he is as good as advertised. I thought more than twice probably about 6 times. I am also worried that If I have a mixture screw wrong and am lean I don't want to ruin a new engine. I think they are good...( I am 95 % sure they are good) but I like to have piece of mind if that makes sense. I should have them back by Friday. I am dropping them off tonight. I will want to know what he found was ailing my 89 sp because it is driving me insane.

 

[needforspeed]

Bump:biggrinjester::banghead:

 

[needforspeed]

Dr.Honda,
On your old yellow sea poo, with the carb settings and jets do you still have the whole stock air baffle / flame arrestor or whatever you call that big black plastic tube thing? When I got these two dinosaurs, the stock air boxes were gone, as well as the oil pumps. So I am wondering if I am using your jetting and H/S L/S if maybe this is part of my issue. I had it out yesterday it ran great on the trailer in the water, I put my hand half way over the hole on the flame arrestor and it cleaned up and ran pretty decent. So I made a restriction that I coud clamp on and fired it up and ran it on the trailer again. It ran really well once I got it dialed in. I ran it for ten minutes.nice crisp throttle response all the throught the throttle range....So I left it idle, put on my life jacket and pushed it off the trailer and hopped on while it was still running. I go to give it throttle and bla stalls. Now I am adrift and it won't start!:cuss::bs: This thing is possesed. It will only run on the damn trailer !!!!!!!! I am going to go into the fuel tank and check out all the fuel pickups again I just don't know what else to do.. I am thinking crank seals now even though the crank is supposedly rebuilt.....

 

[Dr Honda]

Yep... I have the stock flame arrestor on it. For a single carb, on a stock engine... they flow plenty of air.

I don't think a problem as bad as you are describing is because of an aftermarket flame arrestor. Sounds like you have a fuel issue. When I first start my Si... it will be fine, and I can idle out past the no wake zone... but when I hit the throttle the first time... there is a 50/50 chance that the engine will stall. This is because the high circuit is empty. But... after I restart... it will be fine. (and be fine the rest of the day)

If yours is stalling all the time... then the carb(s) are messed up. It could be an air leak, or plugged passage.

If the problem was just the aftermarket air filter... then dropping the pop-off will normally take care of it.

 

[needforspeed]

Yep... I have the stock flame arrestor on it. For a single carb, on a stock engine... they flow plenty of air.

I don't think a problem as bad as you are describing is because of an aftermarket flame arrestor. Sounds like you have a fuel issue. When I first start my Si... it will be fine, and I can idle out past the no wake zone... but when I hit the throttle the first time... there is a 50/50 chance that the engine will stall. This is because the high circuit is empty. But... after I restart... it will be fine. (and be fine the rest of the day)

If yours is stalling all the time... then the carb(s) are messed up. It could be an air leak, or plugged passage.

If the problem was just the aftermarket air filter... then dropping the pop-off will normally take care of it.

Ok I have no anything on it. just the metal part that says bombardier that sits on top of the brand new carb with brand new n/s, brand new 67.5 pilot, and brand new 130 main. There is the flame arrestor but the big plastic tube and baffle thing is long gone. So I guess I will either start scouring Ebay for one or make something that will restrict the air flow. The plugs look good. Not too lean... nice chocolate brown color. Why would it run good on the trailer and once it is off the trailer start acting up? I am going to go through the fuel pick ups after work tomorrow. I am stumped. The only thing I can think of is it is sitting on the trailer, on the ramp it is on and angle and maybe the fuel tank pick up has a crack and when it is on an angle the crack is covered but once in the water floating on its own level, it stops picking up fuel???? I am grasping at straws here.....If I have to make this air baffle I guess I could get a 2" piece if pvc and drill some holes in it..I don't know

 

[Dr Honda]

The big plastic thing shouldn't change it enough to cure what you are telling me is wrong.

You can't tell anything on the trailer. When on the trailer... there is no load on the engine... and an engine that is ready to blow up will run fine. When you put a load on the engine... the fuel must flow perfect to get it to go. Basically... what you are telling me, is that your ski is running out of fuel. SO.........

1) The arm on the needle is bent too far from flat, and fuel isn't flowing.
2) The high circuit is plugged up.
3) The pop-off is too high, and you can't get a transition to high RPM's. (that's why the little restrictor helps)
4) The upper 2 transition orifices are plugged, and it won't allow you to transition.

 

[needforspeed]

The big plastic thing shouldn't change it enough to cure what you are telling me is wrong.

You can't tell anything on the trailer. When on the trailer... there is no load on the engine... and an engine that is ready to blow up will run fine. When you put a load on the engine... the fuel must flow perfect to get it to go. Basically... what you are telling me, is that your ski is running out of fuel. SO.........

1) The arm on the needle is bent too far from flat, and fuel isn't flowing.
2) The high circuit is plugged up.
3) The pop-off is too high, and you can't get a transition to high RPM's. (that's why the little restrictor helps)
4) The upper 2 transition orifices are plugged, and it won't allow you to transition.

Thanks for the response. I guess I will start withe the pop off pressure because everything else is good. Pop off is 26 psi the same as my other one. I set them up exactly the same. Why one runs and the other doesn't is what is confusing me.

 

[needforspeed]

Dr.Honda, ....so are you saying that without that air baffle thing that the pop off pressure needs to be lower? I could make my own baffle out of PVC pipe if I had the measurements of one. Or I could lower the pop off pressure since there is no baffle there. I just need to be led in the right direction. I used your settings right to the jetting and pop off pressure and needle and seat size.

 

[Dr Honda]

Really, at 25 ~ 28 psi... it could run without an airbox.

Could the pressure from your fuel pump be low? Have you rechecked the pump to make sure that the check valves are seating?

OK... I know this is a PIA... but you could try swapping carbs. If the problem follows the carb then you will know.

 

[needforspeed]

Really, at 25 ~ 28 psi... it could run without an airbox.

Could the pressure from your fuel pump be low? Have you rechecked the pump to make sure that the check valves are seating?

OK... I know this is a PIA... but you could try swapping carbs. If the problem follows the carb then you will know.

I was laying in bed trying to go to sleep last night and was going through the fuel system in my head.....why would it run on a trailer and not in the water?....The only thing different when the trailer is in the water is the angle from the ramp.....the pump is loaded and in the water so I didn't think it was that....It has to be the angle.....so I said to myself....self, if there was a crack in the fuel pickup up high maybe when it is on the ramp on an angle it is covered with fuel and when the ski is flat on the water then the fuel is below the crack and it is sucking air.....well after work today I stopped by Lowes and picked up some fuel line...$4.00...lol.... when I pull the fuel pickup lines what did I find? a just about broken all the way around old brittle cracked fuel pick up......so I changed out both the on and the reserve on both machines.....even the one that had been running they were broken and brittle...just down further so they were probably always below the fuel level...Anyway....tomorrow after work we shall see if I finally figured this out. I will be happy but pissed at the same time if a 1 dollar piece of rubber hose cost me a riding season last summer. Happy that I figured it out this early for this summer. I hope this was it. It seems logical and it makes sense but this thing has been driving me out of my mind...I am feeling confident but I don't want to be cocky... Last year it would run if I kept pumping the primer.....I am crossing my fingers....lol

 

[IDoSeaDoo]

When I started reading this thread, this instantly popped into my head. I'll bet $20 that that was the problem. I had a similar problem, except my pickup lines broke after we flipped my 92 GTS. It wouldln't start b/c the little strainers broke the line when it turned over. We were two miles out and swam/paddled back 1 before someone finally pulled us back in. Curious to know if that was indeed the problem

 

[needforspeed]

bump :thumbsup::cheers:

 

[B_PWC]

Glad to hear you got it fixed!!! I had the same issue with the pickup lines breaking but it would not run at all because they broke high.

 

[needforspeed]

When I started reading this thread, this instantly popped into my head. I'll bet $20 that that was the problem. I had a similar problem, except my pickup lines broke after we flipped my 92 GTS. It wouldln't start b/c the little strainers broke the line when it turned over. We were two miles out and swam/paddled back 1 before someone finally pulled us back in. Curious to know if that was indeed the problem

Well, I will find out in a few hours as I already have the trailer hooked up so as soon as I get done work I am going home and getting in the truck to tug them to the ramp for some testing. I hope that is all it was.