Johnson 30 HP, Starting-up

[MarkHoc]

I've inherited a 10' Dory with 1990 Johnson 30HP, J30ELES. It's been idle for over a year when I received it, and I've spent the last couple of months cleaning it up. I'm getting close to turning the key and wanted to ask the gurus for pre-ignition advise. p.s. I'm new to this, so all good advise welcome!

 

[tashasdaddy]

Re: Johnson 30 HP, Starting-up

welcome to iboats. this is good no matter how old the motor is.

http://forums.iboats.com/showthread.php?t=158086

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Thanks for the excellent link. I think the engines in fairly good shape, I've had to take the casing apart to get it stripped, re-powder coated and re-sprayed, and in that process (and in getting it all back together) i haven't found anything that looks obviously wrong or worn. I've only had to replace the rubber mounts, the remote steering kit, and a few nuts and bolts and gaskets. My feeling now is to turn the key and see what happens?! any reason(s) why this wouldn't be a good idea?

 

[tashasdaddy]

Re: Johnson 30 HP, Starting-up

turn it over by hand first, after getting it to run, replace the impeller, with a water pump kit. the carbs also may need to be totally cleaned and a rebuilt kit installed. the reason, is you do not want to damage it by running the fuel mix wrong, or burning it up.

 

[Harker]

Re: Johnson 30 HP, Starting-up

I wouldn't start it without changing the impeller and lower unit oil. Well..maybe I would but I'd be ready to shut it down quick if water wasn't shooting out the tell tale.

 

[HighTrim]

Re: Johnson 30 HP, Starting-up

I would also compression test it

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Appreciate all the advise, thanks guys. I'll change the gearcase oil. The impeller's seems to be in good condition, ('tho, I'm not sure what a worn one looks like. i'll have to change the gasket when I put the gearcas back). I've got no idea what condition the carbs are in, but going by the general condition of everything else i'm inclined to think it wont be a problem. I don't have the kit to do a proper compression test, turning by hand all seems as it should -i'll check again when i've put the lower unit back. So, double checking... I'll turn the key, see if it starts, if it does - i'll check there's water coming out. If all's good then i'll let it idle for a while. If the carbs need attention, it'll stall or I'll know, and be able to shut it down quick. ?

Sorry, should have added it'll be running on a pre-mix 50:1, so if it runs the mix'll be good!?

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Started-up today. Engine idles well with plenty of (warm) water coming out with the exhaust, but nothing from the tell tale . I let the engine idle for a while, checking the engine temp with my hand to make sure it didn't overheat. Engine did get warm, but i could keep my hand on there 5 seconds easy - still no tell tale? i've checked for obstructions and searched the forums for clues and am not sure what's best.

Would i be correct in thinking that the tell tale is only an indicator that water is cooling the engine - the warm water that comes out with the exhaust is actually cooling the engine?

I'm wondering if i removed the exhaust cover, i'd be able to clean the channels that feed the tell tale?

Help would be gratefully received, thanks.

 

[F_R]

Re: Johnson 30 HP, Starting-up

Pull the telltale hose off the fitting and poke a wire through the hole. May simply be plugged up.

If it runs OK at all speeds, you may have gotten lucky with the carb. Old gas is a sure-fire way to gum up a fuel system though. How's the tank? Rusty inside? Does it smell like gas or does it stink?

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Hi F_R, Just had a rummage for some wire and found some pipe cleaners, I'll give it a try. Thanks for the advice.

I've only let it idle so far and it seem fine. Fuel tank is plastic and i cleaned it and fuel lines prior to refilling with 50:1. Wasn't much left in the tank anyway (didn't look too bad, but changed it anyway). Hoping things will be okay when i take it out and test under load at all speeds

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Okay, pulled the telltale hose off (no blockages there) and managed to thread 34" worth of pipe cleaners into the hole. A couple of sticky moments, but could have just been tricky bends. Pipe cleaners came out pretty clean . Any idea how much wire is needed?

 

[Harker]

Re: Johnson 30 HP, Starting-up

Did you CHANGE the impeller while the lower was off? The warm water out of the exaust is the best way to tell if there is cooling water going through...the telltale is just like a warning horn to me. Might just be a bug got in there and will get blown out when running a little higher rpm's. You could change the thermostat after the water test.

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Hi Harker, the impeller was in good condition so i didn't change it. With a lot of warm water coming out with exhaust i think impeller's not the problem.

Since you mentioned the thermostat, i noticed there's a temperature switch. Has that got anything to do with the tell tale?

 

[HighTrim]

Re: Johnson 30 HP, Starting-up

Heat switches, installed in each cylinder head, are in series with a "HOT" warning horn in the remote control box. Should an irregularity develop in the cooling system and cause abnormal water jacket temperatures, the switches close the warning circuit. Have you tested this by grounding the tan temp wire? The alarm should sound.

Did you clean the nipple and hose out? Little critters love to nest there. Or simply leave them off and run the motor to see if water exits where it should. I would of changed the impeller while the lu was down. Cheap part, but its failure is catastrophic.

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Hi HighTrim, thanks for the info re: heat switches. I'll test the warning horn like you said. Does the engine need to be running for this?

I understand about the impeller, not so easy to get hold of here in the UK. Would have to wait weeks for it to turn up. It really was in good condition, nothing missing or worn and still flexible.

I checked for blockages, I've no idea why there's no telltale?

 

[HighTrim]

Re: Johnson 30 HP, Starting-up

Did you try running the outboard with the tell tale line and nipple completely removed? Still no water exiting there?

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Hi HighTrim, I haven't run it since i checked for blockages with the the pipe cleaners. I'm not convinced there's a blockage there, the pipe cleaner didn't seem to get stuck and it came out fairly clean. It's late here now and the boats back in the garage, so will have to try tomorrow.

I tried grounding the tan temp wire with just the ignition on and got no alarm, will try this again when it's running.

Thanks for all the help.

 

[HighTrim]

Re: Johnson 30 HP, Starting-up

When the tell tale is not functioning, it is the actual length of rubber hose that you removed or the 'nipple' that attaches to the cowl that is usually blocked. The rubber hose is usually only a few inches long, unless it has been re run atop the cylinder head.

Nipple vvv

 

[MarkHoc]

Re: Johnson 30 HP, Starting-up

Hi all, took the boat out and everything worked out. Thanks for the help and advise received from all. Like i said, i'd kinda fallen in the deep end with this boat - and i'm happy to say that if it wasn't for the help received from you guys i definitely wouldn't have got there.