Suzuki DF90A Low Compression

[wkwarrior]

Looking at buying a 09 DF90A with low compression on #4. The dealer said that it may need to be bored out and new piston. Hours unknown and it has a 2 month old lower unit.

Question - it is possible to have the motor strike something hard that damage the lower unit (hence new lower) unit and bend the crankshaft/connecting rod that eventually cause the low compression?

[artdf175]

I would think that the two are completely separate problems
the most likely problem hitting an underwater object with the prop is obviously taking out the prop.. and some of the damage may depend on if the engine was running an aluminum prop over stainless.. aluminum the prop is going to take a lot of the impact..
after the prop, the next impact is the lower drive shaft the prop is mounted on.
I touched a submerged piling and slightly bent the stainless prop, not repairable, with a slight deflection in the lower drive shaft.

--that would not translate to low compression in the #4 cylinder.
if an impact was bad enough for damage to go further up into the engine, it most likely impact drive shaft or the connecting rods..

The dealer should have the ability to plug in and find the engine diagnostics which would have the number of hours on the engine..

and IF you are going to go as far as tear the motor down to rebuild the cylinders,, get a good quote .. it is probably more expensive than you might think
and lastly, my .02 cents worth is not to buy a problem from the start..
Art

[wkwarrior]

yes, agree. the dealer selling the motor is not forth coming. seems like they have something to hide. they did compression and it was around 125 psi on 1 to 3 and 0 psi on 4. price is too high and too risky. your 0.02 C is spot on.

[18pontoon]

0 psi to me seems like a much worse problem than just bad compression. A head gasket will not fix it. Sounds like a hole in the cylinder, or a severe valve/cam issue. Have them pull the head at their expense and figure out what the problem really is before doing anything else, or find another motor.

[catacom225]

compression

Pure a little engine oil down the bad cylinder then test, If still no compression could just be a bad valve

[artdf175]

WKWarrior
you were correct.. it is too risky..
The dealer should be black balled for trying to unload a really bad engine on unsuspecting customers.. at any price..
if they took it in on a trade and didn't do their homework first.. that is their mistake
I can only suggest finding another dealer t work with that has some ethics.
Art