1990 VRO Johnson 60hp top end issue

[jilang]

I just purchased a 1990 bass buggy with 60 HP Johnson TJ60TLESM. The motor starts and runs fine at mid range on down. If I open the throttle all the way it runs great for about ten seconds and then acts like the throttle is intermiitantly being opened and closed. I tryed squeezing the primer bulb while running WOT no change. The bulb gets hard and stays that way for awhile then will quickley collaps. I have taken the VRO off and run it through the trouble shooting chart with a vacuuume and pressure pump. It passed with flying colors. Any ideas would be appreciated.

 

[WillyBWright]

Re: 1990 VRO Johnson 60hp top end issue

Welcome to iboats. <br /><br />Try backing off the throttle. You may be hitting the rev limiter. The previous owner may have propped the boat for a heavier load. Do you have a tach / what does it say at full throttle?

 

[jilang]

Re: 1990 VRO Johnson 60hp top end issue

The tach is not working at this time. But I'm sure its not hitting the rev limiter. It behaves like it is running out of gas. Occasionally it will completely die if I don't back it down. The rpm is steady for about 10 seconds WOT before it acts up. Also if you slowly increase the throttle it will start to act up before it reaches the RPM it runs at WOT. Does this motor have the S.L.O.W. system? maybe a temperature switch issue?

 

[ob]

Re: 1990 VRO Johnson 60hp top end issue

If the fuel line primer bulb is colapsing,it is indicative of either a faulty bulb or a flow restriction upsteram of the bulb.Check the pickup tube in your fuel tank as well as the anti-syphon valve on the tank hose fitting.New fittings are pretty cheap anyway.

 

[Sebrof]

Re: 1990 VRO Johnson 60hp top end issue

if the bulb is collapsing , maybe the gas tank vent is blocked and the engine is pulling a vacuum at high revs and has enough venting to run at low speeds....just a thought..

 

[jilang]

Re: 1990 VRO Johnson 60hp top end issue

The bulb isn't collapsing on its own. I was describing its behavior while I was squeezing it.

 

[OBJ]

Re: 1990 VRO Johnson 60hp top end issue

jilang...if I understand your post correctly, if you squeeze the primer bulb till it's firm and hold it, then it just suddenly or quite quickly colapses....that correct? When you repump the bulb, does it feel like it's empty until you pump the gas back up to it?

 

[jilang]

Re: 1990 VRO Johnson 60hp top end issue

Yes you are correct in your discription. It takes at least couple of quick squeezes to get it pumped back up hard.

 

[Wakeboarder Tom]

Re: 1990 VRO Johnson 60hp top end issue

Check your fuel lines - we had a very similar problem on our '89 70hp Evinrude.<br /><br />If there a fuel line which is even slightly loose, it can pull air in at high revs when the suction is highest - this causes the mixture to get too lean.<br /><br />Have you also checked the pipe from the crank to the fuel pump - again, any holes/leaks can really scr3w up the fuel pump!

 

[jilang]

Re: 1990 VRO Johnson 60hp top end issue

Trouble resolved. It was a problem with the VRO.<br />I installed a fuel pressure gauge. The fuel pressure would drop to zero when the motor faultered and the fuel bulb would get hard and could not be pumped. Maybe a check valve problem. In any event I installed a new 4 wire VRO and this resolved the issue.

 

[mattjenna]

Re: 1990 VRO Johnson 60hp top end issue

Originally posted by jilang:<br /> Trouble resolved. It was a problem with the VRO.<br />I installed a fuel pressure gauge. The fuel pressure would drop to zero when the motor faultered and the fuel bulb would get hard and could not be pumped. Maybe a check valve problem. In any event I installed a new 4 wire VRO and this resolved the issue.

Where'd you get the new VRO unit from? Cost please?<br /><br />Good to hear problem resolved.<br /><br />Thanks<br />Matt

 

[jilang]

Re: 1990 VRO Johnson 60hp top end issue

Ishopmarine.com $241. but their shipping is pricey.

 

[mattjenna]

Re: 1990 VRO Johnson 60hp top end issue

Thanks for that-expensive lil' bugga's aren't they.<br /><br />Matt

 

[ricko]

Re: 1990 VRO Johnson 60hp top end issue

jilang,<br /> Whear did u hook the 4th wire up I cant figure out whear it goes the purple wire thanks I have no terminal board with a purple wire on it so it sats to go into the connector wire and find a purple wire and ( cut into it??)<br />Ricko

 

[jilang]

Re: 1990 VRO Johnson 60hp top end issue

Ricko,<br /> The purple wire is inside the factory harness that goes to your ignition switch.<br />You will have to split the heavey black jacket lengthwise about 2 to 3 inches back from the heavey red plug. This is just a switched 12 volt positive wire, so if you don't want to cut into your harness you could look for another switched 12 volt source I supose.<br />Jim