Hi there,

I don't know if anyone can help me.

I have been offered a sports boat which has a Johnson 235hp outboard.

I think the date is mid 1980's, and it appears to be in reasonable condition for the age.

I was wondering whether anyone knows whether there is anything to watch out for with this engine, any particular traits etc.

I can not remember the name of the make of the boat though, but it is about 22ft, very narrow.

Cheers for any help,

Matt

http://www.screamandfly.com would be the best place to ask.

powerpacks fail regularly,they suck some gas,hence the two thirsty five nickname,other than that a decent old crossflow!

If it has VRO's (variable ratio oiling) disconnect them and mix the oil with the gas. The VRO's work via vacumm pulses from the engine. Hence a broken, cracked, or disconnected, vacuum hose can destroy an engine.
Other than the VRO's the old Johnsons are pretty good engines.

BTW:Mercury uses gear driven oil pumps for the injection of 2 cycle oil. Much more reliable.

Offshore Addiction beat me to the "two thirsty five". I had a johnnyrude with VRO. It was refered to by the mechs as very rarely operates, or very risky oiling. I disconected mine and mixed it with the gas.

Rapair out of Texas, I believe, makes upgraded power packs for a reasonable price. At onetime, they warrantied theirs forever, but quickly reduced that to a shorter timespan. Course it is hard to beat Ebay prices on power packs if you feel lucky.

Ummm, not to be disagreeable here, but I disagree. The VRO pump is almost foolproof. It does run off vacuum but it is attached to the same diaphragm as the fuel pump. If the line gets disconnected then it stops pumping fuel and oil-you stall and wonder what happened???? Most of the "VRO" failures occurr because someone forgets to fill the tank or never cleans the tank and the lines get clogged up. I have never seen a powerhead failure that could be conclusively blamed on the VRO, but outboard techs have always heard they suck so that is what all OMC failures are blamed on.

If the engine has an older style pump without the three wires coming from it (low oil sensor) and you decide to keep the VRO, just buy the new style pump and harness and you then have an alarm that will activate if oil is not reaching the pump.

I have 2-235's that run great (for sale BTW-with a boat ) but they are kind of thirsty (1 MPG on a 26 foot boat).

Those old cross flow motors require the best fuel you can find. They have a very heavy piston that holds lots of heat causing coking and ring sticking and blown power heads

I ran my VRO low on oil one time and the alarm went off. I refilled the resevoir and it still wouldn't go off. It made me nervous, so I went ahead and swapped the oil pump for a new one. I took the old one apart to see what was wrong. As far as I could tell, there was no way for the pump to reset itself to turn the alarm off. The new pump was pumping WAY too much oil, do I disconnected it and mixed the oil with the gas.