User Tag List
Thanks: 0
Likes: 0
Results 1 to 13 of 13
-
06-21-2013, 08:06 AM #1
93 MPH Johnson 235 crossflow - then scilence as I coast to a stop. Help!
I was out in the boat the other day trying out a 34" cleaver; when my motor died. I had noticed the motor had been more difficult to start then normal the past while and it seemedto like it if I held the enricher button in for a few seconds after it fired upto prevent stalling and lean sneeze. With the 34 and only myself in the boat I was able to achieve 93MPH @ 6000 RPM, the acceleration seemed quite a bit slower than when I ran a 32 ET to 91MPH @ 6400 a few days before. When trying out the ET my flywheel came loose and I had to call it quits. I lapped the flywheel to the crankshaft and installed a new woodruff key.
Anyways this time out I held the enricher button on startup and she roared to life; I idled out and warmed up the engine. Ran about 10kms (6miles) at various speeds with one or two full out blasts. The motor was still pulling when I reached 6000 but I had to let off for turns in the river....given the space I'm sure it would have ran 95. I stopped and adjusted my engine height,then when I fired it up again it idled a bit rough and had a mild squeaking noise; after finding nothing obviously wrong I headed back tothe boat launch. It felt like it was lacking power so I kept the RPM around 4k to attempt to make it back. Then after another minute of running gently it just completely shut off and all I could hear was the wind as I coasted to a stop; embarrassingly right in front of a fisherman whom I had just blasted by at 90 like I was the king of thewater. doh! …at least he was kind enough to give me a tow.
I hit the key and the motor would not turn over with the starter; it was possible by hand but clearly stiffer than normal. After the motor cooled itwas much freer. All the plugs looked good except for one which had the electrode melted off. I pulled the head last night and the lowerright hand piston is melted on the top face; there are flakes of aluminum onthe head but they flaked off easily. The cylinder bore had a bit of aluminum on it but it too will come off – I don’tsee any scoring of the liner.
<!--[if !supportLists]-->- <!--[endif]-->Timing is at 26° @ 5000 RPM
<!--[if !supportLists]-->- <!--[endif]-->I run 94 octane fuel
<!--[if !supportLists]-->- <!--[endif]-->I mix 40:1 synthetic oil
<!--[if !supportLists]-->- <!--[endif]-->Compression is currently 110, 109, 105,109, 105, 20
Why would this have happened?Last edited by Fullthrottleguy; 06-21-2013 at 08:34 AM.
1989 21' Skater - twin 2.5s
1986 Cougar 21MTR, 15" 300XS - sold
2002 TUFF 21 (#0.1), 300xs - sold
1986 Valero YT, 225 Promax - sold
1987 Viper, 140 cross flow - sold
-
06-21-2013, 08:27 AM #2
It is likely fuel was not actually 94 octane.
I have encountered this many times back in the 90s. Run 100LL and it won't do that.
John
-
06-21-2013, 08:40 AM #3
I would also degree the flywheel and check for double firing. Everytime I melted a piston in my 2.6 it was usually becasue the power pack was double firing on that cylinder.
Ralph Musser
27' Fountain Fever W/ 525SC
22' Rapid Craft W/ Evinrude 300 V8 January 2009 BOAT OF THE MONTH SOLD
24' Triton 240 Gold W/ Mercury 60
14' Royalcraft W/ Evinrude 75 father/daughter project
-
06-21-2013, 08:51 AM #41989 21' Skater - twin 2.5s
1986 Cougar 21MTR, 15" 300XS - sold
2002 TUFF 21 (#0.1), 300xs - sold
1986 Valero YT, 225 Promax - sold
1987 Viper, 140 cross flow - sold
-
06-21-2013, 08:53 AM #5
That is the same thing that happened to my GT175.
-
06-21-2013, 12:37 PM #67000 RPM
- Join Date
- Apr 2001
- Location
- Central Florida
- Posts
- 2,643
- Thanks (Given)
- 6
- Thanks (Received)
- 37
- Likes (Given)
- 32
- Likes (Received)
- 219
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
Looks lean to me. 94 is a good idea but shouldn't be necessary with those heads.
-
06-21-2013, 02:24 PM #7
I was under the same assumption....otherwise every crossflow out there would be blown up too. When I tear into it tomorrow I'll take a look and see if one of the jets on that cylinder was plugged. The piston looked very dry to me whereas the others were somewhat wet. Could a bad lower crank seal lead to this as well? Would it cause the poor starting and lean sneeze at idle that I was experiencing too? I ask because I noticed the day before that there was a bit of fuel down the front of the mid after a run that I had never noticed before. Also upon removing the powerhead there was some fuel in the adaptor plate where the crankshaft meets the engine.
1989 21' Skater - twin 2.5s
1986 Cougar 21MTR, 15" 300XS - sold
2002 TUFF 21 (#0.1), 300xs - sold
1986 Valero YT, 225 Promax - sold
1987 Viper, 140 cross flow - sold
-
06-21-2013, 03:06 PM #8
Possible transfer port cover leak???
Mike Dowling
-
06-21-2013, 04:06 PM #95000 RPM
- Join Date
- Feb 2012
- Location
- Canada
- Posts
- 346
- Thanks (Given)
- 0
- Thanks (Received)
- 1
- Likes (Given)
- 0
- Likes (Received)
- 6
- Mentioned
- 0 Post(s)
- Tagged
- 0 Thread(s)
If the 94 octane fuel that you are using is the Sunoco/PetroCan gas then you are using oxygenated fuel (to make the octane rating) and I would stay clear
The best gas for us Canadians is Shell super (no alcohol)
26 deg timing is the absolute limit too.
-
06-21-2013, 06:00 PM #10
Hey your water deflectors are blocking off the cooling to the bottom cyl and partial block off the the center cyl. You can see bottom and center cyl are overheating.Get some new deflectors in that motor!
-
06-21-2013, 08:24 PM #111989 21' Skater - twin 2.5s
1986 Cougar 21MTR, 15" 300XS - sold
2002 TUFF 21 (#0.1), 300xs - sold
1986 Valero YT, 225 Promax - sold
1987 Viper, 140 cross flow - sold
-
06-21-2013, 08:37 PM #12
Greg is right-- the little diverter hose stuffed into the block passage is moved from its correct location, which may have blocked cooling flow to the cylinder. Look at the lower diverter compared to the one above in the second photo.
'89 Hydrostream Vegas XT, '90 Merc 2.4 Bridgeport PCU EFI
My YouTube videos________My Flickr photo gallery
http://www.facebook.com/profile.php?id=1706097519
-
06-22-2013, 07:27 AM #13
Yes the deflectors are designed to force the water to the top on the exhaust side then down the cooler intake side, with the bottom cyl blocked off the water could not leave the cyl and over heated that bank. I am surprised your temp buzzer did not go off you need to check that. What does the other side look like. Also I am not a fan of Sunoco fuel. Be aware of blended gas pumps,the hose can hold a lot of 87 octane.