1990 Johnson 90hp Leaking fuel from Crankcase???

Hi everyone, first time on boards, I thank you all in advance for any help with this issue. I own a 1990 90hp Johnson, model VJ90TLESB, she just got carburetors rebuilt, compression on all 4 cylinders 115psi, starts and planes fine. Carburetors needed rebuilding due to the bowls being warped and leaking fuel. I thought this was the problem with a constant drip line of fuel coming down the midsection of the motor (see pic). Even running engine out of fuel still causes this drip line of fuel. Upon further investigating, I noticed one of the crankcase bolts loose (starboard side, see pic), trying to tighten it, just spun in place. I backed it out and someone before me helicoiled the bolt in but it was now loose. I retaped hole with 1/4" 20 tap and recoiled hole, added red loctite and new 1/4"-20 bolt which was a bit longer to grab more thread. All worked fine, started engine right up and runs fine, but clearly did not fix leak. The hole that I retaped has a lock pin right below it.

1) Could this be the cause of the leak?
2) What would cause this bolt to loosen?
3) Could the gasket be compromised causing this drip?
4) Any ideas of what to do? (obviously pull power head and tear engine apart up to this gasket is already in the back of my mind)

Thanks for any help in trying to save my family from a summer of no water fun.

Facts------There is no gasket between the halves of the block.----Just very , very thin sealer.------I would replace the $2.00 gasket on the bypass cover to see what that does.

Thanks racerone, I checked all recirculating valves and all check out fine (as another forum suggested), then I pulled the port side lower bypass cover as this is where I noticed more fuel dampness. Low and behold the gasket was broken apart. I will order all 4 of them and replace and see if she is still dripping. The reed cover to crankcase gasket looks ok from the top and sides, would you suggest I also pull this and see if it is compromised? Anywhere else, other than fuel lines and carburetors that has a gasket that I should check. I believe we narrowed it down but before I put it all back together I would like to replace any other gaskets in that vicinity before putting her back together or pulling the entire powerhead. Again thank you for your advice.

Replace the 4 bypass covers and test run.----Top marks to you for doing simple checking here.

Hi racerone, even with the bypass covers off and rags stuffed in the ports, she was leaking somewhere underneath. She is leaking somewhere else too and it has to be the crankcase halves. I did not want to go this far and have to go back to pull the PH and split the case to seal it, so I pulled the powerhead today. Can you please tell me what I need to do to split the crankcase. Is it just remove the four 3/8" bolts, taper pins, or do I have to remove the reed assembly and flywheel?

Hi recerone, again thanks for your comment and help. I split the halves yesterday, found a front halve on ebay and waiting for it to be delivered. Fastbullet on iboats said, you can use different front halves just leave out the taper pins on reassembly. Do you know why I should leave out the taper pins when using a used front halve?

I ordered a 2nd hand front halve because I found .013" warpage near the loose bolt and near the broken mount. See pic, I was too concerned this may be the area of the leak.

The blocks are drilled ,tapped and taper alignment pins installed.. Then block is split and reassembled and machined . You leave out alignment (taper pin) and let crankshaft seal rings and bolts do the aligning. You do not want a front halve with deep sealing ring grooves hammered into it!! The damage and problem your seeing is usually the halve was dropped or block fell of table when being repaired..

When you reassemble use gelseal where black lines are...use a thinbead wipe with finger on the bearing areas but out of oiling passages. BRP started this on the Etec motors and really quietens the internal noise..

Wow, thanks, I would have just put a bead around the entire flange and holes, this is very much not in the manual!