1990 Johnson 90 VRO xflow

[generalleeuk]

Hi all, thanks for having a look.
I have a xflow 1990 90hp V4, running on 50:1 premix. The bores/pistons are worn and if you crank the engine over cold you can hear 1 of the pistons slapping loudly. I have removed the exaust cover plate and the left hand cylinder head and you can press/move the pistons sideways! I first heard this sound last year and I have reassembled the engine and put about 30 hours on since, she was ( 50 hours ago ) doing 95 psi per cylinder with 1 psi variation between cylinders when cold. When she runs cold shes a bit clattery on start up, but when warm pulls well is responsive and sounds sweet as a not!
The questions I have are; Are these V4's worth reboring ect be about ?650 to do it my self, or should I run her till she blows, or sell her on and be honest to the buyer (I would be up front about whats wrong)?

I do like the engine, its been very good in the 3 seasons I have had her. Quite trouble free and has loads of power and torque.

Thanks in advance for any input!

 

[emdsapmgr]

Re: 1990 Johnson 90 VRO xflow

It's normal for the pistons to have some movement, even when new. The compression is fine. These crossflow engines will develop an internal piston slap noise when they get high hours on them and the internal powerhead clearances open up with wear. The slapping noise is not an imminent prelude to failure, but does give an indication of repairs needed at the next teardown. You may find the piston to cylinder clearances over factory spec, meaning you will have to overbore it and install new oversize pistons. During any overhaul you will want to also change the impeller, new thermostats and overhaul the carbs. That said, a shop can give you an estimate on these repairs. Check the total repair cost vs. that of replacing the engine then decide.