1999 Yamaha Ls2000 (HELP NEEDED)

[Jesujsol12]

Hello forum Iam new to the forum as well as new to the jet boat world, I recently bought a 1999 Yamaha Ls2000. My first issue was that out of the water both engines fired right up no issues, but while in the water my driver side engine wouldn’t take the load(idle increase) and it would stall. My passenger side engine runs great I don’t think there is any issues with it( compression read 120/120/120)last time I checked. I also should mention the fact that my driver side engine smoked heavily (I know they will smoke some since they are 2 stroke) i also have to add the fact that my oil pump has been removed, I’m doing premix( what’s the right way to premix, if any?) so to not confuse anybody I will list the questions separately I apologize ahead of time for any confusion
1.Can the idle be adjusted, mine reved about 3k at least on bad engine gauge, my other gauge doesn’t even move(any suggestions on repair that issue)
2.Whats the right way to premix?
3. what should be done after the boat sits for a while And I want to start it back up( sea foam, draining tank?)
4.My driver side engine is currently being rebuild byPWC Engine,are these engines ran in sequence, can i at least do another compression test on my good one even though my other engine is out?
5. One of my clean out plugs is stuck, any suggestion on how to release?
6.My three bolts on my cone impeller are missing, where could I buy these? Any idea of why they might even be missing? I have the cobra jet steering by the way
7.when I put back my carburetor should I replace all the reeds or what suggestions can I get for when I put everything back together?
Thank you all so much for taking the time and reading my post, any help would be VERY MUCH APPRECIATED.

 

[tdonoughue]

Hello and welcome! Great to have you here.

I don't have a 1999 LS, so I can provide some limited help...

3. This is pretty universal. I would recommend a) take the battery(ies) out and take to the local auto parts store to confirm they are good and charged, b) as to the fuel, I'm a cheap @##$%, but if it has been sitting a long time (>1 yr), get rid of whatever is in the tank and replace with fresh fuel (treated with Stabil 360, because I always do). You may have issues still, but start with that and let us know what you get...
4. Yep. On mine, the two engine systems are almost completely independent. Regardless, nothing on one engine should affect the compression readings on the other.
5. It is a pull-out one, right? Not a screw-out one?
6. Stupidity? CJS steering should not have anything to do with it. But I can think of no valid reason why the cone bolts would not be there. Seek out some new ones. Parts vendors are in the FAQ.
7. In doing carb work in general, replacing fine parts (ports, reeds, jets) is always the best, especially if you can't effectively clean them. If that is not possible (lack of parts, parts too fragile, etc.) you clean them as best you can and put them back and hope for the best. At least that is how I have always done it, with pretty good results.

Good luck. May be several other folks who can fill in the blanks and/or disagree with the above. It is all good. We will get you there.

 

[the MfM]

There’s a throttle adjustment screw on the front of the carb racks... adjust to ~1200rpm in the water.

The ‘99 ls has the original (threaded) cleanout plugs. Whatever you do don’t damage them as they are $$$$ to replace if you can even find one. Model year 2000 and newer boats have the second (common) pull out plug design...which were then replaced with third design (threaded again) a couple years ago.

You can look at the reeds when you do the carbs and replace them if needed. Generally on the boats they don’t need replacement. Always go with OEM (mikuni) carb kits.

I’d take one of the cone impeller bolts from the other side to a fastenal to find replacements.

 

[Jesujsol12]

Thank you all so much for the info that has been posted regarding my questions. I have had a busy day at work and I just now got some time to login and view the answers.
tdonoughue: Response 5. my plug is a screw out one unfortunately
6. Yes stupidity is probably the answer because nothing looks scratched or even bent, simply looks like they were never installed back into place tbh
7.sounds good I’ll definitely consider looking closely into all the parts and I’ll clean everything that I can. I will deff update the post with all my progress once my engine comes back this coming week I’m excited.

TheMfM: I Will definitely adjust the throttle In the water For both my engines. I have to put my driver side engine back in once it comes back from being rebuilt.
These plugs are truly something else, I think there should be a better upgraded kit for these since I have heard several people say they’ve had issues with them.
I will certainly use ONLY mikuni carb kit if needed I will get to work on the cone bolt and everything else next week upon arrival of my new engine. I will be posting pics and info very soon.

Again I truly appreciate yalls info and taking the time to read/reply to my post, I can’t stress enough how awesome these forums are with tons of knowledgeable jet boat owners. God bless you all.

 

[tdonoughue]

So, then, on the plugs, as they are screw out ones, I think the only two tricks of which I know are a) the ice trick--fill the hole with ice, let it sit there for an hour or so, then dig out the ice and try to remove, and b) trying some penetrating oil around the edge of the plug in the hole--let that sit for an hour or so and try to remove.

I guess the only other thing I would offer on the carb is always adjust before you decide you need to rebuild... So certainly try @the MfM 's throttle adjust before breaking things down.

Update us! We like pics, too.