Need some help with compression

[Kwint]

I am trying to help my father in law with a boat he just recently purchased. It is a 1974 Larson 1550 with a 1972, 100 HP johnson engine. We have rewired the entire boat and are currently working on the engine. Right now, I know there is an issue with the starter as it does not engage properly unless it is tapped on the side. But, when it does engage, it can not turn the fly wheel. Even trying to pull start this thing is a job. I pulled out all of the plugs and still getting the same thing, although, it's much easier to turn, it's still not turning that much. Any suggestions?

 

[rickdb1boat]

Re: Need some help with compression

Welcome<br /><br />Try putting a spoonful of outboard oil in each of the spark plug holes and then pull it over by hand a few times. Has the motor sat for a long time without running?

 

[Dhadley]

Re: Need some help with compression

It sounds like you'll at least need a starter but go ahead and drop the lower unit. You'll need to repalce the water pump anyway. Then pull the plugs and see if it spins over then. i bet it will.<br /><br />Oh -- and Welcome!!

 

[Kwint]

Re: Need some help with compression

Thanks for the quick response...to answer the question, yes. It is my understanding that the boat was ran all the way up till the end of the 2004 fishing season and has sat till now. Supposedly, the previous owner had it in the shop during the fall/winter of '04 and had it serviced. He said it cost around $500, although, he did not state what exactly was done to it.

 

[rickdb1boat]

Re: Need some help with compression

Not really knowing it's history, other than it was in the shop for something, I'd get a gauge and check the compression before I went much further....You should also remove, disassemble and clean the carbs and use fresh fuel...You may want to read this, also:<br /><br /> web page

 

[ezeke]

Re: Need some help with compression

I think what Dhadley is trying to tell you is that you are in forward gear and that it is much easier to turn the motor in neutral or with the gearcase removed.

 

[Kwint]

Re: Need some help with compression

I put a little oil into each cylinder, after which, it's much easier to turn over the engine without the plugs in place. Once I put the plugs in, it was no better. I'll let it sit for a few days like the page that Dhadley suggested stated to do. <br /><br />As for the manual, my father in law purchased the owners manual from Johnson, but it dont' really offer too much as far as troubleshooting. Mostly just installation. Thanks again for all the tips/suggestions.

 

[Cricket Too]

Re: Need some help with compression

You need to get the repair manual, the owners manual won't tell you too much, as you've already found out.

 

[emdsapmgr]

Re: Need some help with compression

Disconnect the electrical leads to the starter. Make sure your battery is good, or try another battery. Jump the starter direct from the battery with a set of jumper cables. See if the starter works better.