Low end power loss?

[Legdragger]

My 820 Kawi motor which has always been a stump puller has been loosing more and more low end power over the last few rides. It also started to load up on the slow ride out to the surf as well. I have a stock 46 mikuni on it with Delta V Force 2's. I am thinkng I have a reed problem but haven't taken anything apart yet. I am going to check my compression before I get it apart just to be sure everything is tight. It is at the point that it can barely get out of it own way until it gets the RPM's up and then it is a rocket like it always was. Anyone have any other thought's or experiences with loss of low end power? It starts and runs good still just really soft power at low RPM's.

 

[DAG]

maby your low end jet is clogged????

 

[waxhead]

i would guess your n/s are starting to wear
dropping pop off and making it dribble down low (like an old man)

this is causing your rich loading boggy feel

 

[Flash-FX]

Check the butterfly for wear. I also run a single 46 and have had similar issues. That little "e" retaining clip on the butterfly shaft broke off and let the shaft walk back and forth. It wore out the ends of the butterfly pretty quick. Meanwhile,I was compensating for the little hesitation with the LS adjuster...I didn't realize it was broken until I found the broken clip inside the hull. I'm on my 2nd shaft/butterfly kit, With a barrel sleeve (not using the "e" clip anymore)from a dual carb coupler setup to keep things in place.
......Just a guess.

 

[nikad58]

i will bet on reeds.. does it shoot a lil gas back up the carb when you blip the throttle ?

heres a picture of what happened last weekend.. it was running fine then poof.. real boggy.. (we were 20 miles from the ramp, (huntington pier from long beach) it almost made it back before the other one let loose.. no damage was done and both peddles were knocked back into and threw the reed cages.. this ski has skills !!

 

[Matt_E]

I lost a bunch of low end when my motor hydrolocked and bent a rod. It ran great for another couple of hours, but it lost some grunt.
Compression in one hole went from 170 to 120.

 

[93SJ760]

What Waxhead said. I had really spongy bottom end and my machine was loading up when going slow. The issue was N&S leaking by.

 

[Mile9c1]

no damage was done and both peddles were knocked back into and threw the reed cages.. this ski has skills !!

Nice!

The only time I've noticed power loss was with a low compression top end (120psi). Once it would warm up, it just didn't have the same snap as when it was cold.

 

[Legdragger]

I worked on it last night and the reeds are perfect. The carb looked good but it was hard to tell if the needle was good or not. Then after it sat around a few hours it almost looked like the tip of the needle shrunk. I put in a different needle and checked pop off. It is 15.5 pounds with the 2.5 n/s and the silver spring. Checked another carb witht he same setup and it is the same with the old needle. So the needle and reeds have been eliminated. Also checked compression which is 165 in both cylinders so that is eliminated as well. Then I noticed the screen in the Yamaha SJ style spark arrestor had popped up a little which made me wonder if the one screen affects the carburation that much. I popped it back down nice and snug so that is good now. I am going for a ride tonight and I will see if we figured it out.

 

[WAB]

If that does not do it, maybe check the stator to see if it loosened up and rotated clockwise.
Nothing worse than pulling the front cover in an x2. :banghead:
Is your SS gastank as hard to get in & out as the stocker?

 

[Idok]

If that does not do it, maybe check the stator to see if it loosened up and rotated clockwise.
Nothing worse than pulling the front cover in an x2. :banghead:
Is your SS gastank as hard to get in & out as the stocker?

x2

 

[Legdragger]

Just to update my results: I cleaned the carb, swapped the needle, tested it for pop off which was 15.5 pounds with both needles. I also cleaned the top screw on the headpipewith a small drill bit since the pipe looked like it was getting hot. It started looking dry and salty after I ride rather than wet and clean.

Results were AWSOME! It is running stronger than ever. Must have been a little snot on the needle and the clogged headpipe sucking low end power out of it.

Thanks for the help guys!

 

[FL-cracker]

^^^^^Good to hear!

 

[Legdragger]

If that does not do it, maybe check the stator to see if it loosened up and rotated clockwise.
Nothing worse than pulling the front cover in an x2. :banghead:
Is your SS gastank as hard to get in & out as the stocker?

The Aluminum tank comes out in less than a minute with no tools. I can pull it out on the beach if I need to and plug the quick connects into each other and it is sealed tight enough to let float around.

Believe it or not I have been working on the Kawi so much that I have come to appreciate it. I actually like the way they did most of the stuff on it better than my superjet. He electrical connection are superior to my sj and the rest is on par with it. I thijk once you get rid of all the old corroded hose clamps and junk that was made in the 80's that wears out it is a solid setup.