kawasaki 15 trouble

[arosewag]

I have an exmark 48 hydro walk behind. Not very many hours on it. I can't seem to get full hp out of the engine. Not sure what happened, but at full throtle it seems to be at maybe 2/3 power. Really bogs down. I thought it may be the plugs, but I changed them and it still does the same thing. It starts up fine, idles fine, doesn't make any strange noises. I checked the linkage and there is full travel in the throttle. Any ideas?

[lucforce]

You need to get access to a tachometer and verify the top no load rpm's. Check the air filter also.

[Restrorob]

If you post the model and spec. numbers off the engine I will post the high speed adjustment procedure, But as lucforce said you need a tach. to set it properly. You can order one here; http://www.tinytach.com/tinytach/gasoline.php Or purchase the same one at any Briggs & Stratton dealership.

[6'7 330]

Get a tach and see what the rpms are.It is an easy procedure to adjust the RPMS,if it is a V-Twin 15.Under the air cleaner houseing, there is plate,loosen two 10 mm bolts on each side of the plate, take a long screw driver or wrench, and lift up on the plate to raise the RPMS.We put tach's on all the walkbehinds, and Z-Turns. If the air filter and RPMS are ok, it could be a coil going bad, or the thottle linkage messed up.

[Mowingman]

If it is the v twin, I would guess it is likely you have one coil going bad.

[arosewag]

Thanks for the replies guys. Restrorob....can I get just the standard tach? Also, I found an earlier reply of yours to another post that had the schematic for the linkage. I'm going to check and make sure the choke linkage is ok. The diagram will be most helpful, thanks. I did check the air filter and it was certainly dusty. I banged out as much of the soot as I could, but it doesnt seem to be the problem. I started it up without the filter and it doesn't affect the rpms.

[arosewag]

Is there a good online parts supply for coils? Are they easy to replace? I am mechanically inclined and not afraid to take something apart.....only sometimes do I have parts left over after putting it back together.

[oldrustycars]

you guts should listen to Restrorob. you can get the Briggs vibratach for about 15 bucks, they work great, and reasonably accurate. its all ive ever used. but on a machine you make your living with, get that tinytach and you get an hour meter as well. installs in seconds, just wrap the wire around the spark plug lead. now you can watch the rpm's all the time, and maybe adjust the ground speed accordingly. plus the hour meter...you might be surprised how many service intervals you've missed.

[Restrorob]

The diagram will be most helpful

Well I need your model numbers to look it up because there are a couple different 15's and I don't want to misinform you. changing a coil is not that hard of a job but I don't know of a on-line place to get them for Kaw. right off hand. Any tach. will do but the tiny tack is the best bang for the buck as oldrustycars said.

[lucforce]

"It starts up fine, idles fine, doesn't make any strange noises."

Before you start ordering pricey ignition coils, I would verify the rpm's if the above is still true.

[J&R Landscaping]

I know the fb460 and the fc 420 kawasaki engines had iginitors on them that would go bad. I'm not sure if the twin cylinder kawasaki engines have them but that maybe something to check into.

[arosewag]

I ordered a tiny tach. Hopefully I will get it tomorrow. The question is what do I do with it, and what will it tell me. The guy at tinytach said that it will hook up to one of the spark plugs. I imagine I will get a reading for the rpm w/ no load. What will this information then tell me? Before anyone answers maybe it would be best if I first get the results. Thanks for all your replies.

[6'7 330]

I ordered a tiny tach. Hopefully I will get it tomorrow. The question is what do I do with it, and what will it tell me. The guy at tinytach said that it will hook up to one of the spark plugs. I imagine I will get a reading for the rpm w/ no load. What will this information then tell me? Before anyone answers maybe it would be best if I first get the results. Thanks for all your replies.


Check the RPM'S without the blades spinning, then with the blades engaged. If the RPM'S drop off significantly with the blades engaged, it probably is a coil.

[arosewag]

I put a tach on it and it was running around 3200 rpm no load. I called a local gravely dealer who happened to have a few of the coils there. While there I had his mechanic take a look at it. He found that one side had no compression......doh!!! The adjustments for the valves had backed out and one of the rods was just laying there. Luckily no damage, rod wasn't even bent. I lucked out bigtime. I didn't realize it, but the kaw. manual says to adjust the valves for clearance after 300 hours. I figure the mower has between 300 and 400 hours. Anyhow, all is well. I only mow one day per week. This mower went down the previous week, so I was mowing half speed this past friday. To make matters worse, the rear hydro motor mount on my stander completely fractured on friday. So, I was down to one half speed mower on the only day I mow. Got em all fixed now, gotta go mow.