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Update! -No compression in either cylinder. Guessing head gasket? Worth repair or get new motor?

Hi. I have a Husqvarna mzt61. Fired it up, engaged pto. Blades spun. Through earmuffs sounded rough\racket and maybe weak. I shut it down. After looking things over, it will not start. Cranks strong. Would bad pro clutch keep it from starting? Fuses good. Blades don't spin when cranking.

Your PTO clutch is not in play at start up, there are safeties involved to keep it from even spinning over if the clutch is engaged

Doesn't sound good...those Kawasaki's are decent engines...is the oil level okay? I would do a compression test first. Not sure what type of noise you heard but engine noises are generally not a good thing. How many hours on it? How long did it run before the noise?

kbowley said:

Doesn't sound good...those Kawasaki's are decent engines...is the oil level okay? I would do a compression test first. Not sure what type of noise you heard but engine noises are generally not a good thing. How many hours on it? How long did it run before the noise?

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What crystal ball are you using? M-ZT61 came with both Briggs and Kawasaki depending which version the OP has. Just can't assume they only have Kawasaki engines.

And what difference does that make regarding the issue?

Bertrrr said:

Your PTO clutch is not in play at start up, there are safeties involved to keep it from even spinning over if the clutch is engaged

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Right. I was just giving any details I could think of. I didn’t know if they ever ceased up in engaged position. Thanks

kbowley said:

Doesn't sound good...those Kawasaki's are decent engines...is the oil level okay? I would do a compression test first. Not sure what type of noise you heard but engine noises are generally not a good thing. How many hours on it? How long did it run before the noise?

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Briggs motor. Oil is good. Sound from what i recall was a clunking or grinding. I noticed right before that it seemed weak. I only made it about 50 feet, engaged the pto, heard problems then shut it down. High hours. I just got it used. Thanks

kbowley said:

Doesn't sound good...those Kawasaki's are decent engines...is the oil level okay? I would do a compression test first. Not sure what type of noise you heard but engine noises are generally not a good thing. How many hours on it? How long did it run before the noise?

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Just did test. No compression in either cylinder. Yikes. Guessing culprit has to be head gasket? Would you consider that worth the repair or get new motor?

Not a head gasket, pull the valve cover off and take a look at the rocker arms while rotating the engine by hand to ensure they are moving as you rotate. Sounds like a failed camshaft. What year is the machine? Please post the Husqvarna model number and serial number of the unit.

kbowley said:

Not a head gasket, pull the valve cover off and take a look at the rocker arms while rotating the engine by hand. Sounds like a failed camshaft. Quite common on the older Kawasaki engines that used a plastic cam gear. Not sure what year they changed to a new cam. What year is the machine? please post the Husqvarna model number of the unit.

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Thanks. Will do. Watching yt videos. Its a briggs. See what i find when i open it up.

kbowley said:

Not a head gasket, pull the valve cover off and take a look at the rocker arms while rotating the engine by hand to ensure they are moving as you rotate. Sounds like a failed camshaft. What year is the machine? Please post the Husqvarna model number and serial number of the unit.

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Covers off. One exhaust push rod out of place, but it appears in good shape. Lot of play in rockers but idk what’s normal. Other rockers intact and valves move. Researching.

jeffro79 said:

Covers off. One exhaust push rod out of place, but it appears in good shape. Lot of play in rockers but idk what’s normal. Other rockers intact and valves move. Researching.

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Did you check both cylinders? The valves need to be adjusted while you have the cover off. Valve clearance is about .003 for intake and .005 for exhaust. This needs to be checked on the compression stroke. You can use a small screwdriver through the spark plug hole to feel the top of the piston movement as you rotate engine. When the piston comes up to the top of travel and just as you very slowly rotate the engine until the piston begins to go down VERY slightly. Feel both rockers to be sure they are loose then set the clearance with a feeler gauge. it may take multiple times to get them right. You can find YouTube videos to show you how to do it. If you are unsure, bring it to a shop and have it done. However, the rocker falling off will not cause low or no compression since the valve stays closed with the rocker arm off. Are you sure your gauge is working correctly?

No compression means your pistons are no moving up and down. Broken rods

hlw49 said:

No compression means your pistons are no moving up and down. Broken rods

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The OP stated that one of the rockers popped off the pushrod. However, that would mean that the compression should be okay since the valve remains closed. So, you have a good point HLW49, it could be both rods. However, in most cases, the engine will not rotate smoothly if the rod(s) have failed, or it will make a noise while doing so. We shall see when he adjusts the valves using a screwdriver on top of the piston to get TDC.

hlw49 said:

No compression means your pistons are no moving up and down. Broken rods

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You were right unfortunately. Both rods gone. Bent camshaft. Scarred crank.

kbowley said:

The OP stated that one of the rockers popped off the pushrod. However, that would mean that the compression should be okay since the valve remains closed. So, you have a good point HLW49, it could be both rods. However, in most cases, the engine will not rotate smoothly if the rod(s) have failed, or it will make a noise while doing so. We shall see when he adjusts the valves using a screwdriver on top of the piston to get TDC.

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Thanks for all the feedback. I got it all opened up because pistons weren’t moving. Both rods gone, bent camshaft, scarred crank. It ran fine till it didn’t. Had high hours and probably hot because covered with more crud than it should’ve been. I got it used this year. Did not get my money's worth. Gonna llook up part costs, motors, etc.

Probably was only running on one cylinder and then the second rod failed. I even one engine with one broken rod and a large hole in the crankcase the customer was still using but brought it in complaining of low power.

If it is in decent shape otherwise, I would try to source a replacement engine. Those are pricey machines new. A new Briggs twin will run you roughly 1k with shipping...your local husky dealer may save you some after all told, maybe not. Be sure to get a 16-amp alternator and fuel pump. It would be okay with a 9-amp alternator as well. There is a gent local to me that has tons of used engines but if you can swing, I would go new if the machine is in decent shape, otherwise, try to source a used I/C series or Endurance series. The decision is yours as to weighing the options. A new engine is still cheaper than buying a used MZT. You can try Smallenginewarehouse.com and they can sell a drop in, not sure of the price, give um a call. A 40 or 44 cubic inch is plenty of power to run it well.

Sounds like broken cam?

StarTech said:

Probably was only running on one cylinder and then the second rod failed. I even one engine with one broken rod and a large hole in the crankcase the customer was still using but brought it in complaining of low power.

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I have an engine in the workshop that only had 1 rod in it from new
Customer brought it in for a service complaining that his 18Hp twin had less poke than his on 10Hp single .

kbowley said:

And what difference does that make regarding the issue?

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Duh...

kjonxx said:

Sounds like broken cam?

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jeffro79 said:

Briggs motor. Oil is good. Sound from what i recall was a clunking or grinding. I noticed right before that it seemed weak. I only made it about 50 feet, engaged the pto, heard problems then shut it down. High hours. I just got it used. Thanks

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I swapped a 22HP Kawasaki twin for a Briggs 21 HP single on a Cub Cadet RZT50. Wiring harness plugged in all correct, Shaft length and diameter all matched up. Plug and play. Kawasaki had hole in block. Push rods are Puny compared to the Briggs. Gotta keep these motors clean and full of oil or else...