1995 Sl750 not firing on all 3.. Help

[madrani]

The ski has not been started since last season. Also the display was shorted and the battery would run down in hours maybe minutes. I have disconnected the display and the battery stays charged. I started the ski and it will not rev. and has no power. It is getting fuel on all three plugs. I replaced the plugs and took it to the lake. It would not run right. While it was idleing I pulled the plug wires off one at a time. The two towards the back of the ski made no difference when pulled but when I pulled the front one it would die. The only plug that was hot was the front one. Its like its only running on one cylinder. Can anyone help me with this. Thanks in advance. It was not running like this when it was put in the garage last season....

[Wet Wolf]

just for **** and giggles, ck comp. insert guage, hold throttle WOT and crank over to get a good reading, guage in one, plugs in the other 2. If comp is good ( in TX, that motor should crank over 125 - 140 per cyl, and that should be good to go. Put in new spark plugs (cheeep) if ou have any doubts as to the condition of the battery, replace it. nothing sux more than sitting on the lake with a dead batt. beside, to get a good comp reading, you ned a good batt. Good luck

[madrani]

well ive tried everthing I can think of and what I have been told to do. I checked the compression, new plugs, new plug boots, new battery and it still does not run right. It shows fire when holding the plug against the head on all cylinders. It seems like it is running on only the #1 cylinder. Its the only one that will cause the ski to die when the plug wire is removed while running. The ski will even run with the #2 and #3 plugs out. It runs the same as if they were all in. Does anyone have any suggestions. The ski ran fine when put up for the winter. The only other problem I have had is with the display burning up and causing my battery to short out. That is all better now since I have disconnected the display. Please help....

[Bryan Glynn]

Well, you could have a bad CDI or stator...

[Wet Wolf]

are the plugs on 2 and 3 wet or dry when you pull them out?

[madrani]

I think I have figured it out. The #1 plug is the only one getting fuel. I pulled the top cover off of the carbs and started it up. The only one spraying fuel was #1. I have pulled the carbs off but haven't opened them up yet. I did gently blow some air into the fuel line and air only came out of the #1 carb. I hope after I go through the carbs that this fixes it. Whie it was running I sprayed some carb. cleaner in the #2 And #3 and the rpms picked up. This is what led me to check the carbs. I will let you know how it turns out. Thanks

[Wet Wolf]

bingo. :D When you pull the carbs apart, look carefully for brown slimy lookin stuff. when you pull the diaphragm covers off, it will be hanging around on the bottom side of the carb "bowl" if it is there, check your fuel seperator/water trap for signs of the same stuff. if it is there too, then you've got the grunge, it is an algae that lives in gas, you will need a biocide to kill it. let me know what you find.. been there.

[SeaLion]

There's actually something that grows in gas? I bet it's some nasty s**t.

[madrani]

Well there was nothing growing in my carbs. The needle and seats in the #2 and #3 carbs were stuck with bad gas. I cleaned them up and everything looked great. I put it back together and it started right up and seemed to run great. Off to the lake today and it starts out ok. It will run real sluggish on take-off and will eventually pick up and run ok, until I stop or take quick turns and it goes back to not revving again. I check the plugs and they seem ok except the #3 seems too wet. I did not mess with the air screws while I had the carbs out. Should I start fresh with the air screws? If so what should I start with. I have bpr7es plugs, are they ok? I will probably take a new set out with me next time. Any suggestions? Thanks in advance...

[Wet Wolf]

first and foremost. did you remove the jet block to verify that the jets were clear? gum on the needle valve could mean stuff plugging up the jets. ?#2: which way were you turning when it bogged? if it bogs turning right, then its too rich. if it bogs turning left, then its too lean. if its too lean. that might signify partially plugged jets. most of the time, you can see through the hole in a jet and you assume that its clear, when it really has a ring of varnish built up on the inside that effectively restricts fuel flow and is just like putting in a smaller jet. I have seen jets that were restricted up to 50%, that the customer thought were OK becuse they could see through them. when i showed them thier jet and a new jet side by side, they were totally amazed. they could plainly see the difference, even with such a small hole.
Point is: if i made you doubt the fuel flow qualities of the jets in your carb, pull them off again and verify thier condition. while you are there, sounds like #3 might have a bad needle valve(leaking). or less compression in the cylinder leading to inefficient burning of fuel and a fouled plug.
Good luck on your carb quest. hint, next time you have them off, clean off the sealant that polaris puts on the threads that hold the carbs on. it makes it a cakewalk to take the carbs off. once you loosen the nut, you can spin it off by hand easily. [img]/graemlins/winkanim.gif[/img]

[arhaney]

If enough varnish has built up inside the carb, you may find it necessary to soak in carb cleaner (Berryman etc.) Sometimes this is the only way to clean all the passages. Word of caution: all
rubber/plastic parts must be removed from caarb before soaking!