New Power Pack And Still Doggy

[nebraska_woody]

1989 Johnson GT200... has new powerpack and waterpump/waterpump housing just last week. Although the new PP does help with low speed idling and smooth running (or smoothER running), what else can I do to keep this beast running till I can afford to rebuild it? I got a quote to rebuild it for 3500.00 bucks... does this seem high to anyone or is it just me cause it's my money going into this thing??? When running WOT it'll run for a short time (a few minutes) and then will start to sound like it's flooding out.. loose power, RPM's go down and will die. It usually starts back up right away and I can do the whole thing over again with the same results. Anyone know what that could be? I know my compression is running between 70 and 75 across 5 cylinders with one in the high 60's. Sorry for a lack of direction with this post as these are all things i'm trying to figure out. One of the things I'm wondering from you veterans is... can I help the beast run smoother by using a higher octane fuel than 89, or using a lead additive in the tanks as well? Being a kid when this motor was built, I dont remember if it was meant to run with leaded or unleaded gas. Thanks to anyone who can help me out on this.

 

[marinegrh]

Re: New Power Pack And Still Doggy

hows your fuel system, any air leaks, hows fire, you say good compression, but one cylinder in the high 60's, is this the 6th cylinder your refering to, you describe several different types of problems, some are easy fixes, some are a litle harder to define and repair, id start knowing what you know, with compression, fire and fuel, need these 3 to keep it running, do you have a service manual, if not, pick one up at your local dealer, wont hurt the pocket to much, and pays for itself the first time you do a repair yourself<br /><br />good lick and keep us infoed

 

[nebraska_woody]

Re: New Power Pack And Still Doggy

Hi.. yes I do have a manual.. just got it, so I've been reading as much as I can on everything. From everyone I"ve talked to, the compression is very low compared to normal operation. I dont have a compression tester yet, but am working on that part.. I dont remember which cylinder it is that's the weakest, just going off of the last mechanic that I've had it too. How do you test for air leaks in the fuel lines? (or should I be reading the manual before asking such questions?) I've never touched the lines or anything since I bought the boat so I'm not sure how to get started doing that part of it. Had it at the boat doctor and he put in 6 new plugs, so I can only assume he did things right.. with the right plugs and all. I"m looking forward to saving some money this winter doing some of the simpler repairs myself, but completely rebuilding it is beyond my capabilities at this point. Any suggestions on the fuel leak test? Thanks for responding so fast too.

 

[nebraska_woody]

Re: New Power Pack And Still Doggy

PS... something I read in the manual is it does not recommend leaded over unleaded.. or vica versa...although it does mention both could be used. could using a lead substitute help "cusion" any of the internal parts, or help the rings seal better in the cylinder?

 

[Cricket Too]

Re: New Power Pack And Still Doggy

Nebraska....Try rebuilding the carbs and decarbing the motor and see if you get any results. Decarbing will usually increase the compression and if you have never rebuilt the carbs they could probably us it. Good Luck.

 

[Cricket Too]

Re: New Power Pack And Still Doggy

P.S. What was the reason a new power pack was put in?

 

[nebraska_woody]

Re: New Power Pack And Still Doggy

MMCPECK,<br /> I took the boat in for an estimate to the local boat shop... he claimed he only checked the compression and did nothing else at that point. when I came to pick it up one night to take the kids out in it. That night when I picked it up, and got it in the water, it did not feel like it ran on all 6 cylinders. It took forever to get on a plane, and top speed was only 38 mph (when i'm used to 48 or so)I took it back to them explaining what it was running like.. that's when they said that the powerpack went bad. I trusted them and it does run better than it did all summer with the new powerpack in, but I still think it's a little fishy that the PP went bad in the same time frame that they had it in their shop for 2 weeks. Could it be possible they just forgot to hook something back up and blamed it on a bad powerpack so they wouldn't look bad?

 

[rickdb1boat]

Re: New Power Pack And Still Doggy

nebraska_woody <br /><br />Invest in a compression tester and check it yourself. Those numbers sure sound low for that year Motor. I'm betting they are higher than you were lead to believe, unless the motor is severly carboned up or has been run to death. That is first and foremost before anything else. Then be sure you have good spark on all cylinders. Then check the carbs.

 

[nebraska_woody]

Re: New Power Pack And Still Doggy

I'm betting on the "run to death" scenario myself.... but I dont know for sure as I only had it for a year. When doing the compression check, does a person take all 6 plugs out, and screw the tester into each cylinder... and then turn the key over... reading the meter... repeating for each cylinder? I'm not mechanical enough to know exactly, but that does seem the logical steps to me. Can you, or anyone else for that matter address the question I had about the lead substitute additive? Thanks.

 

[rickdb1boat]

Re: New Power Pack And Still Doggy

Matt<br /><br />Pull all 6 plugs and do one at a time, as you said. It will not run any better using a lead substitute, as this is not required in a 2-stroke Motor. It is designed to run on unleaded anyway, as there are no valves like in a 4-stroke engine. Don't discount this engine yet. Do the compression test and take it from there. As you said,

That night when I picked it up, and got it in the water, it did not feel like it ran on all 6 cylinders. It took forever to get on a plane, and top speed was only 38 mph (when i'm used to 48 or so)I took it back to them explaining what it was running like.. that's when they said that the powerpack went bad. I trusted them and it does run better than it did all summer with the new powerpack in, but I still think it's a little fishy that the PP went bad in the same time frame that they had it in their shop for 2 weeks.

I also believe it's Fishy sounding!<br /><br />(Heck, if it's on a trailer now. Drag it up to the nearest automobile service station and have them check the compression real quick. Cheap!)

 

[Solittle]

Re: New Power Pack And Still Doggy

When you do the compression check put the muffs on and turn on the water - dosen't need much. You can damage the impeller by turning the motor over with no water going throught the water pump.<br /><br />On the compression check - Make sure you get a testor thet screws into the spark plug holes and not the kind with the rubber end that you hold against the plug hole. I have seen compression guages vary in readings by 20 pounds from guage to guage on the same motor. Even compression accross cylinders is more important (up to a point) than the actual reading. +/- 10% is OK.<br /><br />For your winter project review:<br /><br /> http://www.outboardrepairs.com/carburetors/ <br /><br />Also run with 87 octane.

 

[nebraska_woody]

Re: New Power Pack And Still Doggy

Thanks everyone for the help and advice on this. I'm going to pick up a compression guage this weekend on my way through town and check it for myself. I'll keep you all posted on how my experience goes with this monster. On those types of guages that screw in, do they seal themselves pretty good in the screw hole, or could I use something like teflon tape to make sure there's a good seal for accurate readings??

 

[even125]

Re: New Power Pack And Still Doggy

Hi the threads seal tight no need for tape i usually just do it up finger tight if it is not a recessed hole. If you use tools to do it up just a soft nip up is all that is needed. Be carefull of the spinning mechanicals and dont use flywheel as a convenient shelf for a multimeter like I once did!! I am hopeing your engine springs back. good luck. even125

 

[nebraska_woody]

Re: New Power Pack And Still Doggy

thanks even.... and thanks everyone else for your input. it's my project this weekend, so I'll keep you updated with it. Have a good weekend everyone!