1998 Johnson 225 Rebuild

[Blakek25]

I am currently working on rebuilding my 1998 Johnson 225 that lost a locator pin in the #2 piston. During the teardown process, I found a few things that I was not sure if they were normal or not.

The first of these was that there was fuel present in the hose connecting the fuel pump to the pulse limiter on the block. Is this normal? I thought this may be a sign that I need to rebuild the fuel pump?

The other issue was that the bottom of the crankcase had a decent amount of oil built up in it (I will post a picture later). I thought this may be caused by a problem with the recirculatory system, but the one-way valve seems to operate properly.

Also, please tell me if this is correct. If the locator pin came out of the piston, this means that cylinder was running hot. I have plenty of water pressure. My water pressure gauge maxes out at 30, and it is usually pinned all the way around past 30, pushing against the pin. Therefore, the heat problem is probably caused by running lean? I am planning to rebuild that carburetor and put a clear line and fuel pressure gauge in the system to check that there is no air in the fuel. Is there anything else I should check that would cause it to run lean? I thought this might also be related to the fuel pump question above.

A little history on the motor. I had a previous problem with the fuel pump sucking air, that I believe caused the motor to blow up last time. I had some trouble finding this problem, and had maybe 15 hours on the rebuilt powerhead before I was able to find it. I had around 130 hours on the rebuilt powerhead before it blew.

Thanks for the help!

 

[Bosunsmate]

Are you running premix? or VrO?
Perhaps the locator hadnt being installed securely the first rebuild.
Id be very careful resealing the two crankhalves, make sure you use a good sealant and liberal amounts.
Also check any water deflectors in the head, if there are some

 

[Blakek25]

I have attached a picture of the excess oil buildup in the bottom of the crankcase.
I realized I didn't describe the failure very well. It was the piston ring locator pin that failed on the #2 cylinder.

I am running the VRO.
I used loctite 518 to seal the crankcase last time.
By water deflectors, are you referring to the thermostats?

 

[racerone]

No water deflectors on your motor.-----Water deflectors are found on CROSSFLOW motors and not the LOOPER models.---Loctite 518 is the correct stuff.----You just need a thin bead ( 1/8" ) as most off it should squeeze out of the joint.------Look into the " shelf life " of the 518 as it should not be used if too old.-----There should not be a large quantity of fuel in the VRO pulse hose.-----Take the VRO apart for inspection.

 

[Faztbullet]

Well 1st off you need to check the plastic restrictors/deflectors in port/starboard cylinders. Also replace ALL pistons as if one pin has come loose the others will follow soon. (Use cast pistons!!!!) This is a cooling issue design problem and is mandatory that you change impeller every 2 year no matter what flow looks like. I highly recommend that the water mod be done to block as I have all my customers blocks done. Make sure you used primer to set the gel-seal or wait 48 hrs to allow a good set. You need to drill and vent the bottom bearing like the later motors as this prevents the build up and increases lube to upper bearing. View attachment MarFab_Tech_Bulletins_D9579.pdf

 

[racerone]

OK----Early looper models did not use a deflectors like the crossflow models.----Later ones added this feature again.

 

[Blakek25]

Thanks for all of the help!
What exactly do I need to look for on those plastic water deflectors?The manual mentions a length that they need to be but wasn't sure if there was something else that I needed to check.
Also, What all is involved in

drilling and venting the bottom bearing?