1997 Johnson 225 Venom

[bobecke]

Can anyone tell me if this is considered a good engine for a bass boat??

Thx

[Cobalti]

The biggest thing to watch out, is that model had problems with the locating pin dissappearing on the pistons. This happened at about 100 hours use. The result was anything from a disintegrated piston, to a hole in the block. A whole bunch of os had them, and they all did it.

Having said that, I have one that has been modified slightly, it will turn a 29 SRX chpooer to 6800rpm(engine speed). The motor is 20kg lighter than a Mercury 225 (3.0l). I opened up the exauste above the propeller, and it was the sweetest sounding motor I've had so far.

You will need to pay some attention to the tilt trim mechanisem, as in stock form it has far too much play in it and will effect handelling. I can give you all the details you want and photos.

[Michael Martin]

If you keep it below 5900 rpm you shouldnt have any problems.
Above that Cobalti's is right. It was a problem on the 96 & 97 models.

Mike

[bobecke]

Thanks guys. I appreciate the info!

[Markus]

I once had the complete list of issues with the late 90s OMC loopers, but I have lost it. I got it from some very frustrated OMC mechanic off some bass board.

Anyway, the locator pin coming out was certainly a problem on those engines, especially if run for prolonged periods in the mid-range.

In addition, for about the same year models, the top bearing holder bolts had the habit of vibrating out.

[bobecke]

Well can this engine be rebuilt using upgraded locaters so this won't happen? If staying under 5900 RPM will minimize the possibility- that might be alright. How fast would this motor rev on a 20' Bullet with a 25" pitch anyway?

[Markus]

I am sure the OMC gurus can pitch in and give you a way better answer than this, but my understanding is that the locator pin problem was due to some shortcut in the production process. Changing to new pistons will certainly fix the problem, but I do not know if there are any cheap fixes.

[ON THE HUNT]

Pull the water blow of valve and make sure they drilled the passageway through to the exhuast water cavity

[Cobalti]

I replaced all pistons, one conrod, and had to resleave one bore. It is not too difficult to do. With a lot of care and a work shop manual, any body could do it. The only specialized tool you need to borrow or steal, is a special clamp used to hold the big end of the conrod while tighting the bolts.

I found the current product to be of far better quality, the con rod was actually visibly different and stronger than the original. The motor has been fine ever since. I know how this person drives! He has a mod vp and only knows two speeds....stop and flat stick! Much like every body alse on this sight. The problem can definitely be fixed.

A cool mod is to fit a V4 OMC fly wheel. It increases your spark, recreases the weight as it is smaller, and the only set back is you now have a 9 amp alternator. There are more subtle mods that will make it scream and fly.

I found the best prop by far for an OMC is the SRX. Do into their web sight to find out the sizes. Also take a look at www.montyracing.com.

[baja200merk]

its debateable
run good oil and fuel like any motor will help it last

just when you r trying to turn it at 6500 with bad oil this is what happens

[baja200merk]

this is the head

[baja200merk]

it had plenty of torque and jumped outa the whole just ran it wit 19 pitch prop so it spun almost 6600 trim down higher trim up but i avioded that

[Roddles]

You should consider running with a 23 pitch prop as the 19 is far too small and will over rev your engine.The 23 will give you plenty of pull out of the hole and improve your top end without over revving

[baja200merk]

yea thanks man

the sad thing is that the 25'tempest plus was in the mail!!

[bobecke]

Thanks for all the replies on this. I just bought a Bullet 20 with this engine and am trying to learn what I can. I've got a manual ordered but in the mean time, does anyone know what the compression should be on this engine? Best oil to use? Should you put a little oil in the fuel as well to augment the oil injection?
It has a rapid jack jack plate which I don't know anything about either.

Thanks
Bob

[baja200merk]

run enough pitch to keep the rpms under 6k and it will last i would add a bit of oil to the fuel cant hurt

i had no vro on mine so i just stupidly mix it wrong or at the wrong ratio (altho i used 50:1 like the book says) well hope this helps have fun with the boat good luck