View Full Version : 27 HP liquid cooled kawasaki engine with no power

05-06-2007, 02:26 PM
i have 27 hp kawasaki motor on my 60" exmark and it gets bogged down very easily. even if i go up a hill w/o the pto engaged it slows down . and when cutting grass it could almost stall it out.
does anyone know what the problem could be?
it starts fine and revs up to speed fine, just no power.

Bill Kapaun
05-06-2007, 04:27 PM
How old are the spark plugs?
Fuel filter clogged?
Fuel pump weak?
Clogged fuel cap vent?

The mayor
05-06-2007, 04:35 PM
Maybe the air filter is dirty.

05-06-2007, 05:42 PM
What tha heck, May as well get my question out....

Are you sure it's running on both cylinders ?

05-07-2007, 05:42 AM
yes it is running both cylinders. as i said it seems to run and rev up fine.
just as soon as any load is put on the engine it kills the rpms. i mean i cannt go more then 1/2 speed cutting grass. and if its thick or up a hil maybe .5 mph. an air filter or plug could cause that much loss of power?

05-07-2007, 06:11 AM
i think i forgot to mention the engine has just been rebuilt,isthere something i am missing?

05-07-2007, 08:25 AM
Was this rebuild done by a shop ? If so take it back to them to worry with.

Or you can check the governor adjustment.


05-07-2007, 04:41 PM
it was not doneby a shop, so ineed to figure it out.

05-10-2007, 03:00 PM
well ichecked the plugs , vent cap, and everything else including the governer adjustment.
still runs the same. is it possible that the valves be out of adjustment enough that i would lose that much power but still be able to run?
if so , can anyone tell me howtoadjust them. i called all the shops in my areas and they are booked up for weeks.

05-10-2007, 06:57 PM
Here Ya go.....


05-10-2007, 08:10 PM
What tha heck, May as well get my question out....

Are you sure it's running on both cylinders ?

Exactly what i was going to ask :D

Otherwise yeah i'd bet a pretty penny that you don't have your valve lash right. I've seen several engines through here that would bog down easily or hunt real bad just because the valve lash wasn't right. It doesn't take much and you'll notice a big difference in performance.

What you describe sounds like a classic lack of compression - you could do a compression test or better yet a leak down test and determine where the loss of compression is occuring. Odds are its improper valve lash and its probably easier for a home shop just to pull the cover and stick a feeler on them per RestroRob's instructions.

05-10-2007, 10:59 PM
Loose valves likely isn't the issue. Engines will run better at full RPM with slightly "loose" valves.

What are your RPM's?

Both free load and blades engaged?

Spark plugs and fuel filter can certainly affect power.

05-10-2007, 11:18 PM
"Loose valves likely isn't the issue. Engines will run better at full RPM with slightly "loose" valves."

Hmmm? Incorrect valve lash can cause hunting and engine bogging because the valves are too "tight". With zero or negative lash one valve remains cracked and can cause burned valves, valve seats and lack of compression resulting in hunting and lack of power.

Also, incorrect valve lash in the "loose" end will hurt max rpm and high rpm power. A loose valve means the valve doesn't open as far and at high rpm this means that the engine isn't able to draw a sufficient charge into the combustion champer to keep up at that speed. Thats why race cars (built for high rpm power) have cams with enormous lift. The engines die at low speeds but can live at high rpm.

The correct valve lash is just enough to allow valves to expand without cracking open and decrease the effects of valve hop at high rpm.

05-11-2007, 03:12 AM
Who rebuilt it? Exactly what parts were replaced in the process? Why was it rebuilt in the first place?

How are you sure it is running on both cylinders. Most V-twins will run very well with no load on a single cylinder. Easiest way to check is use something to pull the plug wires while the engine is running.

05-11-2007, 09:23 AM
Yea....what pugs said......It sounds like it isn't running on both cylinders.

05-11-2007, 10:05 PM
ah you guys are right it seems to run fine but i pulledthe one plug still running, pull the other and it dies.

i havnt had time to try a differnt plug but it was new. could it be anything other than the coil, are there separate coils,(sorry i dont know much about v twins)?
and does anyone know where i could get one cheap . my closest exmark dealer is 2 hours away. and the kawasaki dealer icalled didnt even to bother getting back to me after i called.

05-11-2007, 10:47 PM
ah you guys are right it seems to run fine but i pulledthe one plug still running, pull the other and it dies.

Hmmm, Remove the flywheel cover then remove the small kill wire from the coil and check for spark again. This will eliminate a possible shorted wire, If still no spark replace the coil. Adjust air gap on the new one to 0.010-0.016

You can contact this place for a coil; http://www.rcpw.com/Oem_Parts.htm
But they don't have Kawasaki parts look-up listed. If you post your model and serial numbers off the engine one of us can look the proper part number up.

05-12-2007, 03:20 PM
well to my dis may i just pulled the plug and held it on the block and i do have spark. so it is not the coil. what else should i look for?

Bill Kapaun
05-12-2007, 04:21 PM
Just because you have spark, doesn't mean the cylinder is good.
If no/low compression on one cylinder, pulling the plug wire on one and/or the other just lets you identify the "weak" cylinder.
Check valve adjustment & compression on the weak cylinder.

05-15-2007, 03:49 PM
ok i cant be any happier. its valves are definately out of adjustment. reason being my number two cylinders intake value rocker arm was almost broke in two. push rod was not connected. anyone know where i can get the part number and where i can get it

05-15-2007, 07:36 PM
Post the exact model and spec. numbers and I can look up the part numbers then check a few on-line stores I have saved.

Do you need the valve cover gasket also ?

05-16-2007, 12:48 PM
i called an exmark dealer about 2 hours from me and they are able to drop ship the parts. ihope this is all thats wrongwith it. i cannt sayim too happy with the person i bought this mower from.
byt he waythanks for your help restrorob and others

05-16-2007, 09:25 PM
ok have not got the parts yet but i was turning over the engine to make sure everything was ok. the intake push rod did not seen to note at all when i crank the engine. does it just need pressure put on it? it is seated right