1985 40 Seahorse Johnson

[waterboy30]

Can Some One Tell Me How To Adjust The Carbs On This Motor ? The Motor Starts And Runs Good, But When I Put It In The Water, It Just Boggs Down And Struggles To Get Up On Plane, I Tore The Carbs Apart And Cleaned Them, And Still The Same Result.i Don't See Any Knid Of Adjustment Screws On Them.can Some One Help?

Waterboy30

 

[lexkyboater]

Re: 1985 40 Seahorse Johnson

Hey Waterboy30, welcome to iboats! Not being familiar with this engine, I went to http://epc.brp.com/default.aspx?brands=ej&lang=e and entered Johnson, the year and the HP. Click carburetor and you see a parts breakdown. I doesn't look like this carb has any low or high speed mixture adjustments, guys more familiar with this motor might chime in to correct me if I'm wrong. You can clean and rebuild the carbs, make sure you remove the core plugs too. Rebuild kits come with new core plugs and new gaskets. You can see if you're getting gas in both cylinders by hitting the choke as you're accelerating. If it runs better, you need a rebuild, if it's worse, you're getting gas. Link and Sync may be an issue. That affects timing as you advance the throttle, and carburetion is a passive element while timing is the active component you move to rev the engine. That said, this motor probably adjusts idle with a timing adjustment. There should be a screw on the timing/flywheel/magneto base to set idle. You might want to also verify plug wires are okay, and that you're getting spark. Put an ohm meter on both ends of the plug wires and wiggle them to make sure there's no open circuits. Then do spark test with a homemade spark tester - see http://forums.iboats.com/showthread.php?t=213548&highlight=spark+tester. You'll want spark to jump 7/16" and it needs to be a nice blue spark. HTH, Steve

 

[tashasdaddy]

Re: 1985 40 Seahorse Johnson

good post. i use a small dowel and hammer to replace the core plugs, and here is the tool to remove the jets. i made mine (red/black) with a belt sander.

 

[siusaluki23]

Re: 1985 40 Seahorse Johnson

Have you replaced or rebuilt your fuel pump? could not be pumping enough gas to your carbs.

 

[tashasdaddy]

Re: 1985 40 Seahorse Johnson

also check your compression.

 

[lexkyboater]

Re: 1985 40 Seahorse Johnson

You can check fuel pump if you remove the gas line going to the carb from the fuel pump and crank the engine over. Should get a nice stream of gas if fuel pump is working.

 

[BoatBuoy]

Re: 1985 40 Seahorse Johnson

To test for fuel pump problems, have someone manually pump the fuel line bulb as you accelerate. Also, are you sure you don't have any waterlogged foam in the hull? From your description, it sounds like it's pulling a load.

 

[lexkyboater]

Re: 1985 40 Seahorse Johnson

Or that way. That's how I figured out my 71 9.5 HP had a bad fuel pump. It would idle all day, but as soon as I got on the throttle, seemed like it was running out of gas. Well, it was. In fact, it would die if I didn't let off the throttle. I could keep it running by pumping that fuel bulb though. You can take gas line off of the carb and fuel bulb will shoot gas a couple of feet. You're just doing the job of the fuel pump when you squeeze that bulb. If yours is not dying at WOT like mine was, maybe your fuel pump is pumping more than mine did, but still not enough to keep gas in the float chamber?

 

[waterboy30]

Re: 1985 40 Seahorse Johnson

Hello everyone,
Thanks for the quick reply,,,,you guys are good...Well I cleaned the carbs for the second time..took the boat out this morning, high grade gas and leaned out on the oil/mix..I got it up to 4800 rpms and it planed out pretty nice, but seems like it is still struggling..oh yeah, I also put new plugs in it, one step higher for a higher spark.. I haven't had time to pull the new plugs out , but the old ones were oily/wet/ carbon build up...I'm curious to see what the new ones look like...Some one mentioned the timing , the timing is touching the stopper screw and the butterflys are all the way open,when driven at wide open...Gps clocked it at about 28mph...This just seems alot slower than what I think it should go..Another good suggestion was water logged foam...How would I be able to tell that and fix it if it was true? I live in SC and it is hotter than ---- here and I don't think that really is the problem..But if it is..How can I tell? Everyones help is greatly appreciated...I believe both I have spark at both plugs due to the fact that it does not stutter or miss... The boat runs fine, starts fine, just wont rev up to it's max ( I believe) Help ?

 

[waterboy30]

Re: 1985 40 Seahorse Johnson

one more thing for those who care....I read something about spark plugs with wet/carbon build up could be caused be bad ignition ground...I noticed that when I tried starting the motor with the key and had my other hand on the side,,,I recieved a slight shock ,,,is this normal,,,or is something wrong and what do I need to do to fix the ground,,,the ground from the motor is hooked to the battery , I don't know what else I can do??????

Thanks for everyones help,,,damm dealerships don't want to tell you squat,, just want to charge you that $90.00 shop labor fee...

 

[cr9c1]

Re: 1985 40 Seahorse Johnson

28 MPH isn't bad. I had an old 1960's Seahorse 40 HP on a small aluminum boat, and with just myself in it, it would do at its best, 27MPH. My 25 HP is a much meatier motor. It does 22 with just me in it and 18 with my wife, small child, friend, cooler with food + beverages of the alcoholic variety, gas, chainsaw, and paddle.

 

[jwilkey84]

Re: 1985 40 Seahorse Johnson

I also have a merc. that shocks me when the boat is running and I reach back to manually use the throttle. Any thoughts.

 

[waterboy30]

Re: 1985 40 Seahorse Johnson

I found some data that say if you get shocked by your control box, then you have a leak in your high voltage leads....It basically says these wires are hooked up to your power pack,,disconnect the wires there, if it fixes the problem , then track down the bad wire that hooks to it...