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Discussion Starter #101
Nothing should change the 1.2 will work just need to use correct spring for needle/seat you want to be about 70/80 psi for pop off. I have the chart home.
I think I am popping around 70/80 psi though it seems its on the higher end, nearing like 82-84 psi. I can hear a very small air leak before it pops. I need to find out where it is coming from and seal it to get a more accurate reading and a good 3x average. I had to use some pretty stiff fuel line from Autozone so that may be part of the issue. Where do I need to be with the overbore to 81mm and running the 1.2 needle valve with the 150 and 90 jets?
 

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Discussion Starter #102
Found the leak, not happy either. After tightening all of my hose clamps, I found the air leak (RED RECTANGLE) to be between the carb body and the fuel pump. Some WD40 started spitting bubbles when I sprayed it, it starts at about 40 PSI, very small leak but a leak nonetheless. I have dismantled the fuel pump twice, double checking the seals and looking for debris. Not sure what the issue is.

I may move on to the second carb to see if it has the same issue, maybe even swap the fuel pumps to see if that helps. Any ideas?
 

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Sounds like you're good on the pop off but you'll need to get the leak under control. Try laying the pump block on a flat surface with a sheet of very fine sand paper(400/600grit). Slide pump around then look to see if pump is showing even sand marks. ie, not warped. If only slightly warped try and clean it up on the sand paper.
I converted my carb body screws to Allan headed and used antisieze to get them a bit tighter. Also my screw heads were in sad shape.
 

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Discussion Starter #104
I though it could have been the pump blocks, I found a local store that had a listing for 2 of them so I purchased them. Lo and behold the carb is still leaking at the same exact spot. The 2nd block did fix the leak on the 2nd carb. So I guess there is some sort of warping on the carb face. I like the idea of switching screws, that I will do as well.

I may have attempted a jerry-rig being that I do not have a spare carb and I spread a thin layer of gasket marker on the carb face where it continues to leak. I know this is probably a disaster in the making but I kind of just want to see if this helps then I know what my exact issue is. Does not appear I will be in the water Friday like I had hoped.
 

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Discussion Starter #105
Have some pop off pressure results after the replacement carb blocks were installed.

Carb 1 (Problem Carb)
Sealed leak with GM and let sit for 3 hours
83 no leak
80 no leak
81 no leak
80 no leak

Carb 2
83
84
87
 

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Discussion Starter #106
Two steps forward, one step back. Started to rebuild carbs when I found a few fuel hoses that were cracking from replacement. I will pick up some 1/4" ID from a local place and replace the lines on the carbs.

With the pop off pressure set, do I need to mess with the high and low speed adjusters? I left them as is when rebuilding.
 

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"With the pop off pressure set, do I need to mess with the high and low speed adjusters? I left them as is when rebuilding."

Please tell me you removed them while cleaning and blew out the passages. Then put them back where they were. If not you may have issues if any debris got into the passages.
I'd mark and count turns in to lightly seated and remove and blast passages with carb cleaner and air. Then replace to original settings then back out as below.

back the high out a 1/4 to 3/8 turn. This should help with overbore. I'd back the low out about an 1/8.
 

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Discussion Starter #109
Yes, adjusters were pulled and cleaned, wasn't sure about adjustments moving forward but you answered that. Pulled an all-nighter and got the motor back together. These new powervalves do not seem to be "moving" very easily. I think the shaft and the new powervalve levers are binding a bit. What can I use in the YPVS system to help lubricate, can I slop some waterproof grease in there?
 

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powervalves do not seem to be "moving" very easily. I think the "shaft and the new powervalve levers are binding a bit. What can I use in the YPVS system to help lubricate, can I slop some waterproof grease in there?"

Lube the power valves and shafts with 2stroke oil. They should operate rather freely should have a little drag. If there real tight you'll want to find issue and address. Otherwise you'll burn up the servo motor or they won't operate properly.

I'm concerned with your ring gap. My manual shows .012/.018. your saying you have .0285 is twice what you should have. Did you have the ring square in the bore when you checked?
 

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Discussion Starter #111
Where were you when I needed you at 4 am this morning?!?!?!

j/k :lol2:

Well shit Dave, let me go back and look at my feeler gauge and recalculate, I know it was the first 3 on my gauge. I don't guess the overbore has anything to do with the difference in ring gap...this is more than likely user error. The guy who bored my cylinders knew what he was doing so I either measured incorrectly or in the unlikely event, wrong rings? I have never measured piston ring gap clearance, I'll take the blame.

Dave, I guess my only option is to pull everything off and measure again? I may have to dismantle the YPVS anyways to "smooth" it out.

I did pick up 10 feet of tygon fuel line for $60.00 from local Napa so I will start replacing the fuel lines that were splitting.
 

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Sorry, I was at work lastnight and saw your post but didn't have access to info. Ment to look when I got home, forgot and crashed.
easiest way to check gap is to use a piston top to push the ring in about 1/2 an inch and square to bore. Then measure out against the cyl at its closest gap.
 

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Discussion Starter #113
Well I didn't hit my deadline. We were on the water this weekend minus the skis. Might be a good thing so I don't end up rushing anything. I will be dismantling the cylinders to double check ring gap on both. I also need to replace an oil seal on the power valve system the tore during installation. Carbs have been rebuilt and gas lines replaced. Oil pump and lines are next. Then it's off to wrestle the rats nest in the electrical box.
 

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Discussion Starter #115
"Then it's off to wrestle the rats nest in the electrical box."

What's with the EBox?
I was following the SBT 800 engine removal PDF, when it stated to remove the connections and pull the connector through, all I needed to do was pull the stator off. I have to hook EVERYTHING back up in the box.
 

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Discussion Starter #117
Ok, I see now. I've done it both ways and prefer the stator removal best. It's a lot easier.
After removing all the connections, I noticed the connector inside the box is too big to remove from the box without hacking up the weatherproofing. I would have never undone everything.
 

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Discussion Starter #118
Got the cylinders off, measure gap again, still getting 0.025" on the gap reading, tried to snap a pic. Will the overbore to 81 affect ring gap? Did the cylinders get "overbored"? Do I need to look for a different set of rings?

Carbs are cleaned with new ear clamps and lines.
 

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I'd check you piston clearance as well with this as this may affect them. I'm thinking they sent STD rings with oversized pistons. But they could be STD also.

Get new rings from whoever you got kit from

Piston/cyl clearance .0039/.0041
Ring gap clearance. .012/.018
 
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