Purrs like a kitten then?

kclark1963 · Sep 26, 2003

Hey guys Installed a new VRO pump on my 2000 Johnson 115 hp and it purrs like a kitten for several minutes then sputters and dies. This engine has been rebuilt including the carbs by a local marine dealership with a good reputation. the fuel bulb pumps up firm and the new pump is doing it's job, there seems to be a vacuum leak. I am hoping that it's not the plastic fuel evap tank or recycling tank. Does this engine use check valves in the vacuum system that i should be looking at.

Man i wished i got the Johnson manual instead of the one i bought. any help would be appreciated.

Thanks guys Kevin

OBJ · Sep 26, 2003

Re: Purrs like a kitten then?

Hey Kevin.... Do you have to pump up the primer bulb after she dies? When you replaced the pump, did you also replace the pulse limiter and make sure the connections to the block were secure? Check around the fuel system for loosey hoses and don't forget the connection to the fuel tank also.

kclark1963 · Sep 26, 2003

Re: Purrs like a kitten then?

Hey OutBoardJim thanks for the reply. My understanding is that the pulse limiter is part of the VRO and comes as a unit. and yes i have to pump the ball. The shop did a test by putting the fuel line directly into the fuel tank and the same thing, it runs and then you have to bump the ball. I gave it them for now but they said they would check for a vacuum leak in the vapor seperator tank (plastic) or another tank in that line also plastic. I thought those were only used in the EFI systems and this engine uses carbs what gives?

kclark1963 · Sep 26, 2003

Re: Purrs like a kitten then?

Well I have asked the shop in the past about putting an inline electric pump on but they say they don't know how or it will not work.

I did a search and ran across Luna's post on his looper and he did this very

Any ideas gentlemen Kevin

OBJ · Sep 27, 2003

Re: Purrs like a kitten then?

Morning... Your GT has a small vapor pump. Sits near the top of the fuel rack. Looks like a small fuel pump. Did you or the wrench check the primer bulb it self to see if the valves were still good? Just my opinion here, for some reason the pump is losing prime or the pump itself is defective. The safety issues with electric pumps make an electric pump prohibitive on an outboard or they probably would have been put on a long time ago. Keep us posted as to your progress....thanks.

seahorse5 · Sep 27, 2003

Re: Purrs like a kitten then?

Temporarily hook up a piece of clear fuel line to the inlet fitting on the pump. Run the motor and look for air bubbles that would indicate a leak in the fuel system somewhere. Another way to bypass the fuel system is to hook up a 6 gal. fuel tank and hose directly to the pump inlet, and then run the motor. If it stays running, then you know its definitely in the boat's fuel system. If it still does not stay running, then there may be a kink in the pulse line or a plugged passageway.

kclark1963 · Sep 27, 2003

Re: Purrs like a kitten then?

morning seahorse Thank you for the input, the shop said they bypassed the fuel system and it quit and

still they are looking at the fuel system as mentioned in one of my above replies. the fuel bulb, fuel lines, tank and fittings are all new I'm going down there this morning and suggest they take another look at the primer bulb, pulse line, vapor pump and check for blockage. This engine has less than 15 hours on it

I'm in California so the shop will be open in less than 2 hours. I'll keep you all posted Thank you Kevin

kclark1963 · Sep 27, 2003

Re: Purrs like a kitten then?

could this engine lose vacuum if a spark plug is not torqued in. I only ask because one was loosened at the lake to check it and i'm not sure it was tightened back down.

Kevin

kclark1963 · Sep 27, 2003

Re: Purrs like a kitten then?

Ok, there is 6 lbs of pressure on the pulse side while running, any one know what the spec's are if this is enough pressure, manual does not say and can not get any one on phone from Bombardier to get info. Please help. By the way vapor pump was checked, the fuel system was by passed same thing it quits. No kink in pulse hose.

Kevin

seahorse5 · Sep 27, 2003

Re: Purrs like a kitten then?

The fuel pressure should be above 3psi at all speeds. Put a gauge in line with one of the fuel feed hoses going to either bank of carburetors. You do not use a gauge on the pulse line. Are you sure this is a new pump? If so, if should have stainless steel oval reatainers, held by Torx screws, on each of the fittings. If the pulse limiter fitting and hose are OK, and there is no fuel pressure after a few minutes, and there are NO air bubbles in the line, then the "new" pump may have been assembled wrong or internally faulty.

kclark1963 · Sep 27, 2003

Re: Purrs like a kitten then?

Ok there is good pressure on the fuel side, next up is by passing the small fuel vapor tank and if it runs right, then i would think there is a small leak on that plastic tank and replacement would cure problem. I'll post the results Thank you all Kevin

kclark1963 · Sep 27, 2003

Re: Purrs like a kitten then?

Why cann't you use a guage on the pulse? The shop did and gave me the reading they are at a loss as to what is wrong and by passing the recirc tank is there next test, I'm about ready to start looking for dynamite and deep water.

Kevin

seahorse5 · Sep 27, 2003

Re: Purrs like a kitten then?

You should better start looking for more knowledgable mechanics.

kclark1963 · Sep 27, 2003

Re: Purrs like a kitten then?

I don't know seahorse just a little frustrated and tired is all.

The good news is that I got a couple hours sleep and my sense of humor back

not that i find this funny, but it is a learning experience and once it's figured out I'll have learned something that can be passed on. And there's no other Johnson outfit for at least a 100 miles and these guys have been in business since the 40's and are really nice people

Kclark

kclark1963 · Oct 1, 2003

Re: Purrs like a kitten then?

Well it looks like it was the seal in the vapor tank causing the problem, there out lake testing now and should have boat back this afternoon

I'll let you all know how it goes.

Thanks for all the help Kevin

kclark1963 · Oct 6, 2003

Re: Purrs like a kitten then?

Well I just got back from the Lake and the motor ran great! It was a small o-ring in the vapor pump that was causing all the trouble. The boat has a good hole shot and I took it up to 50 mph @ about 5800 rpm. Thank you who replied with help.

And happy boating

Kevin

Purrs like a kitten then?

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