95 seadoo hx pop off help.

[d6rr3n]

Hi guys, im fairly new to the forum as well as jetskis in general. so far this site has been a blessing, thanks for all the info.

my question is... i have a 95 seadoo hx, stock 717.

ive rebuilt the carbs using genuine mikuni kits, new needle and seats (1.2) genuine mikuni and changed the springs as they ones in there didnt match and given its a 21 year old ski thought best.

ive done some research, and a few sources on the net as well as this forum have stated the pop off should be in the 40-56psi range yet my manual that came with the ski says 20-33 psi?

im literally going through this ski piece by piece and would like a fighting chance to make this beast fly again how it should so could anyone please point me in the right area as to which psi range is correct? ive messaged racerxx and 96spxpos whos been helpful (thanks) but would like some advice from the masses

cheers look forward to your ideas.

 

[mikidymac]

First off let me say that paint job is amazing. Probably one of the best HX's I have seen.

Pop off should be 40-56 with the Black 80gm spring.

 

[d6rr3n]

haha thanks mikdymac [emoji106]

theres a bit if a storey behind it lol.

funny.. theres a guy over here local to me that calls himself a seadoo specialist, been fixing them for about 12 years or more. when i said i had set it to that range he said suggested that anyone could write any old crap on the internet and that i shouldnt listen... this is also the guy that told me freezing my wear ring wouldnt work but guess what.... it slipped straight out lol

 

[mikidymac]

Stay away from those kinds of "Experts".

If it is a stock ski it should run perfect at stock carb settings.

Must be a good story, I see the "CF" or California registration numbers. LOL.

 

[d6rr3n]

haha good eyes.

so a guy was in the raf, and was overseas and bought the hx.. had the paint job done by mike taylor designs.
when he retired he imported this ski and another he had back to the uk with him.

he has trouble mounting the ski and because of this barely got to ride it so sold it to the guy i bought it from. he had it for 10 years, never raced it, looked after it and regretted selling it to me as afterwards he bought a beasty 1500 supercharged kawasaki, but didnt enjoy it as he was constantly watching his fuel gauge drop the whole time.

the guy up the lake where i go keeps going on at me to buy a stand up to be like the other lads.. even if i did i wouldnt sell this! its a one off!

so the guy i bought it from was approached by a tv show called posh pawn to go on the show and ask if he was interested, and if they made him an offer would he be up for it. he said yes but they never got back to him [emoji6] theyre loss is my gain[emoji23]

 

[mikidymac]

Is the engine stock?

 

[d6rr3n]

yeah. i compression tested it and im gettin 180 on both

 

[mikidymac]

180 psi?
150 is fresh stock. 180 is race gas territory.

Can you post some pictures of the engine?

 

[Sportster-2001-951C-Stock]

Pop off is 48 psi on that carb. Please, I don't know why I see a range given every time as none of the factory spec I know of give a range, WUWT? If I look at the range given many times I can select one of two or three springs and that isn't correct so why bother checking pop?

The lever arm should be flush with the surrounding surface, I drag a razor blade across and look for a slight snag.

See the last post here, it's correct:
http://www.seadooforum.com/showthread.php?47468-95-HX-pop-off-pressure-questions

 

[mikidymac]

The range is given because that is what the 1996 Seadoo shop manual says on page 06-03-6. Also on Seadoo source which is a quick and easy reference.

It's also the range given by Dr. Honda in thread #2 in the post you linked to.

 

[Sportster-2001-951C-Stock]

Fine with me, do what you want. I'm just pointing out I can hit some of those ranges using 2 or 3 different weight springs so there's no point measuring pop or using the correct spring.

You might say with the wide ranges we can no longer claim the springs in the kits are necessarily incorrect?

For instance, I could use the black, silver or gold spring in a 1.5 seat to make that 40~56 spec for the GTI and if I have the correct spring there's practically no way I'm out of that spec so why measure?

LOL, I'm not trying to be an ass, it just doesn't make sense.

 

[Sportster-2001-951C-Stock]

180 psi?
150 is fresh stock. 180 is race gas territory.

Can you post some pictures of the engine?

Yep that's going to need the good fuel. Might want to check the calibration of the compression gauge, maybe someone dropped it or something.

This ski looks great in the water, so unusual. Wondering if it's proved to be a chick magnet or just not enough of the right stuff?

 

[mikidymac]

I understand what you are saying but trust me you need to use the correct spring and verify that it is popping in the correct range. I agree that they should all pop at the exact pressure but they don't always and I can explain why but I think that is why seadoo gives you a range. Also keep in mind that popoff pressure is just a test, it is not actually how the carbs operate when running because the diaphragm actually opens the needle not pressure behind it like with the pop off gauge connected.

In the end, use the correct spring and make sure yours pops within the specified range and the closer to sportster's chart the better.

 

[Sportster-2001-951C-Stock]

I understand what you are saying but trust me you need to use the correct spring and verify that it is popping in the correct range. I agree that they should all pop at the exact pressure but they don't always and I can explain why but I think that is why seadoo gives you a range. Also keep in mind that popoff pressure is just a test, it is not actually how the carbs operate when running because the diaphragm actually opens the needle not pressure behind it like with the pop off gauge connected.

In the end, use the correct spring and make sure yours pops within the specified range and the closer to sportster's chart the better.

All exactly correct. Yep, pop is just a test but if it's correct the carb works correctly. Honestly, you can even fudge a little as long as the geometry of the lever makes sense.

Balance the two carbs winthin 1~2psi if possible, closer is better, make sure fuel isn't peeing down the throat with engine off, make sure arm can lift needle off the seat with authority. Using the correct spring is your friend.

Done with the pop thing, good conversation thanks. Maybe OP can soak it all in.

Now be sure to clean those pilot port holes everyone always fights with. I like the cleaning rod idea in the case of these Mikunis (warning: beware of where you're sticking your rod) or acid carb dip but cleaning rod is mucho faster good idea.

The mylar plastic film high speed venturi check valve must lay flat over the hole in the metering plate (kidney shaped plate held by one screw inside the fuel chamber) and should be original Mikuni b/c aftermarket piece might be too thick thus open too late, causing a lean high speed transition dead spot. If it looks good then leave it alone, no need to fix if it's not broken Clean those pilot holes again, instead.

Look over the fuel pump check valves, make sure they're not cracked or bent so the two check valves should seal, the fuel only should move in one direction through them as the diaphragm moves, that's how fuel is pumped. No holes in your pump diaphragm, this can get you into trouble. Reclean those pilot holes again.

Those carburetor base gaskets can slip out of place while bolting up the carbs, I stick them on the intake with some grease. Reclean those pilot holes again.

Final step, don't forget to recheck/adjust the oil injection pump cable again after the carbs and idle speed are final adjusted.

No air leaks in fuel lines, engine won't run right if it's sucking air instead of fuel. Reclean those pilot holes.

Some of the older skis had a rubber pickup hose in the fuel tank, my '95 didn't so this one probably doesn't either

 

[d6rr3n]

hey guys, sorry i didnt reply sooner been working away which is good as was waiting for parts.

thanks for all the advice, i just got to remember how it all goes back together now.
i set them at 45ish psi so will update you once i have it up and running. have to align engine now too. that sbt alignment tool is some piece of kit. smart as!

will be in touch. thanks again! [emoji106]