Does this make sense? What are my options?

[8up]

Hello,<br />I have a 1985 140hp Evinrude. I bought the boat last summer. I just got the boat out of the shop with an intermitant ingnition problem that turned out to be a bad coil. I took the boat out last weeekend and experienced some new problems. When I got out of the no wake zone I opened her up and she reached 5,000 rpm very nice. I slowed down to idle and tried again and it only reached about 4,000 rpm. Next time it slowed out and stalled. After shutting down and drifting for about 10 minutes I opened it up again to 5,000 and it started to die after about 10 seconds then did stall. I tried to restart and the motor would not turn over. This happened several more time back in.I took it back to the shop Monday and got it back today. This is what he said...The VRO no oil alarm went off when they ran it in the tank so they swithed to thier fuel tank. The bogging was more than likley caused by the cheap primer bulb. A long story short. I might have had an oil failure. The motor not turning over could have been the engine stating to sieze. Also a slight knock coming from either the no.1 piston or the top bearing. The top bearing does have some lateral motion. How much if any is acceptable. Sorry for the long post. Any help would be great.

 

[LubeDude]

Re: Does this make sense? What are my options?

Take a compression check! Doesnt sound good, This should tell you where you stand! <br /><br />LubeDude

 

[8up]

Re: Does this make sense? What are my options?

Im' sorry I forgot to put those numbers in there. My original numbers from the 1st time at his shop were cylinders 2,3,4 @ 135 psi and the no.1 clyinder @ 115 psi. Today they were all the same except for the no.4 cylinder dropped to 125 psi. Also I did try to pump the priming bulb during the bogging and it did not help.

 

[Solittle]

Re: Does this make sense? What are my options?

Compression is fine. Were it mine I would pull the VRO & use premix.

 

[Dhadley]

Re: Does this make sense? What are my options?

When the engine locked up and would not turn over -- thats not starting to sieze. It did.<br /><br />Pull the heads and lets see what ya got.

 

[Salty Sal]

Re: Does this make sense? What are my options?

I have a 1985 140 Rude that I just rebuilt. <br />I would switch over to the newer version of the VRO <br />that pumps oil at a CONSTANT rate. The older ones(I think 1984 or 1985 were the first years they used VROs) pumped at a variable rate. The new ones rum under $300. Make sure you have no restricted fuel<br />lines and your water separator is good. Check for air leaks especially at connections. Your compresion sounds real good. Do all warning horn tests for t-stats and VRO system. Make sure that your VRO tank is clean and tubing free of kinks, air pockets,etc. Your going to get alot of pros and cons about the VRO system- but I think most would agree that too much blame is placed on it. But<br />for a small price to pay for peace of mind- upgrade to the newer VRO system.

 

[8up]

Re: Does this make sense? What are my options?

Could this failure be caused by the primer bulb restricting the fuel and running in a lean condition...therefore also restricting the oil to the engine. The mechancic at the shop seemed to think it was posible. The alarm never went off again after he changed the primer bulb.His suggestion was to run the boat with the new primer bulb and mix my gas, but still run the VRO and monitor the oil level for consumtion.

 

[rodbolt]

Re: Does this make sense? What are my options?

hello<br /> pull the head. carefully inspect the cylinder walls. it is possible the alarm circuits for the VRO are not working. a simple test can verify that.before anyfuther damage is done you really need to look for scoring or scuffing. the reason why the engine lost power and siezed is because of a lack of clearence between the cyl walls and the pistons. eventually the piston to wall friction became so great thet the pistons stuck in the bores. there should be no appreciable motion in the upper bearing. usually the symptoms you describe are signs of overheat. lack of oil can make the pistons overheat and not the heads.if ya dont want to pull the heads find a shop that will do a leak down test. not just a compression test. if the laekage is more than 10% tear it down for inspection. the reason is if the cyl walls have vertical scores,the hot gasses will blast past the piston and rings doing further damage as well as contaminating the incoming air/fuel mix causing a lean condition which will cause further damage. see a pattern here ?<br /> good luck and keep posting.

 

[james roach]

Re: Does this make sense? What are my options?

Whatever you do put some oil in the gas. I would pull that VRO. I had one seize up at the dock on me one time and cranked back up. It ran only another minute or so and did it for good. This motor had water intrusion in the cylinders. You should pull those heads and check things out. You are getting excellent advice on this topic. I was young and inexperienced and I wound up buying another motor rather than repairing that FORCE. Learn from my experience. Good luck.

 

[8up]

Re: Does this make sense? What are my options?

Thanks for all of the info from everyone. When you all talk about pulling the heads, are you refering to the "cap" that the spark plug screws into. I have a Clymer manual but it is not a whole lot of help. Also...if I were to do a leak down test on the motor, what are the steps and what would I need. I will try to mearsure the lateral motion on the flywheel with a dial indictor and post the number. I won't be able to work on this until the weekend. Thanks and please keep in touch.

 

[james roach]

Re: Does this make sense? What are my options?

Yes, the plates the spark plugs go through.

 

[8up]

Re: Does this make sense? What are my options?

Hey ya'll,<br />I did forget to mention that the while at the shop the other day after I had the problems, the mechanic said it runs good at WOT. It just doesn't idle like he would like. Could this thing have just overheated the other day and not seized up. A guy at work said his behaved just like this when he overheated. I would hate to look too far into a problem that's not there.<br /><br />Thanks

 

[Solittle]

Re: Does this make sense? What are my options?

If your mechanic got it running at WOT after the problem it did not seize but was binding. It still could have done some damage. The only way to know is to pull the head. Even if the cylinders show some scruffing it may be OK to run it and get good service for a long time. Only one way to find out. It is not a big job.

 

[8up]

Re: Does this make sense? What are my options?

Hello eveyone,<br /><br />I pulled the heads off of the motor this morning. You were right it wasn't much of a job. Anyway...here's what I found. The no's 1&4 cylinders had some wear/grooving. No.1 is the cyl. that has been low since I bought it. The no. 4 cyl. is the one that droped 10 psi compression since the problem day. The other two cyl. look pretty good. With all of the cylinders, the pistons seem to "laydown" in the bore (from the wieght of the piston). I can move each piston from side to side in the cyl. bore. I checked the clearance between the piston and the cylinder wall with a feeler gauge to give ya'll an idea how much I'm talking about and it was around .030. Is this normal? If this is normal...could I clean that cylinder wall up a little with a hone and put her back together? Thanks for keeping in touch.

 

[rodbolt]

Re: Does this make sense? What are my options?

hello<br /> you cannot measure the cyl wall to piston clearence with the piston and rings installerd. you have to measure the clearence at the piston skirt. the best way is to measure the bore in 3 places taking an average then measure the pistion skirts 90 degrees from the pins. then do a bit of math and ya got it. the max on that motor is about .004 and .006 with wiesco pistons. the long grooves were caused by insufficient clearence and the rings and or skirts tried to stick to the walls. usually this binds the rings in the ring grroves.<br /> its time for a rebuild. bore all 4 replace all parts and make the power head new or sell it to the junk man. if your not honest put new head gaskets on it and send it down the road.<br /> good luck and keep posting

 

[8up]

Re: Does this make sense? What are my options?

This is of course what I did not want to hear. What are my options at this point besides replace or rebuild or are there any? Can these pistons be removed without pulling down the engine? I would hate to put alot of money into this 85' motor on a 76 wellcraft v-20. And remember this thing supposedly only had around 40 hours on this rebuild. What all was replaced...I have no idea. The pistons are marked with 020 so we assume they are .020 overbore pistons, is that correct. Thanks again

 

[8up]

Re: Does this make sense? What are my options?

Hello again,<br /><br />I trailered my boat up to the shop yesterday while I still had the heads off. He told me that although the marks I had in the cylinders was not good...I can still run the motor. He said he has seen motors run good with alot more scoring than mine, I should just keep an eye on the compression. So I will premix my oil and run it and start saving some money to replace the power head or something.

 

[rodbolt]

Re: Does this make sense? What are my options?

hello<br /> if you run it with scoring it will die. buy you towboat US or seatow insurance and dont go out when its rough. the sctaches will allow hot combustion gases past the rings thus leaning out the incoming fuel/airmix thus causing more damage thus causing more blowby thus causing more damage. see a pattern yet ?<br />if the rebuild was done properly we would notr be having this discussion. it is possble to go .03 and stay with factory parts. but any rebuild should consist of a new oil pump and check valves as well as t-stats and water pump. you would not belive how many rebuilds I have seen in the norfolk area that were done half way then failed in 15 hours.<br /> good luck and if you decide to run it buy the tow insurance and always remember Murphy's law.

 

[8up]

Re: Does this make sense? What are my options?

I was checking out some of my old posts and it looks like I had left you guys hanging on this one. Since this post I resurfaced and installed the heads with new gaskets, bought and installed a new VRO pump and am currently running 5600 rpms at WOT @ 39 mph. I have also put at least 50 good hours on the boat. I thnak you all for the help.

 

[vinney]

Re: Does this make sense? What are my options?

Do you have go credit? Its time for a new Yamaha Two-stroke of course.