Johnson 200 fuel/oil consumption

N1NE1 · Jul 6, 2012

Does anybody know what the normal fuel consumption should be, i went close to 2 miles today and used 17.2 gallons @ 4000rpms. Its a heavy 26ft seaswirl striper w/a with a 98' johnson 200 ocean pro.I always though it was under powered. Fuel has just been killing me. I used 50gal of gas to 1.5 gal oil. (Boat tops out at 32mph at 5200rpm 4 blade renegade prop 14-1/2x17p)Once in a while if i just floor it a check engine light comes on the goes off a minute later. Definetly using too much oil. Not worried about that though. Over 17gal in that short distance is just crazy.Vro pump going? or are these engines just fuel hogs. Any input would be greatly appreciated =0)

Haffiman · Jul 6, 2012

Re: Johnson 200 fuel/oil consumption

Which of the Renegade versions, Bass or of-shore?
Your check engine is the most worrying, it indicates too high fuel restriction. Check out your anti siphon valve on top of the tank where the fuel line connects!!
Check out your spark plugs. If black and sooty, you are burning too much fuel, if light tan, ok.
However 2 Miles and 17 Gal sounds a bit over the edge!! Sure you do not have a heavy leakage somewhere???

N1NE1 · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

its the offshore version,positive theres no leak, plugs are perfect color. everything runs fine other than check engine one in a while. im positive about the 17gal though. Im going to change the valve and fuel/water seperator and see what happens.

Silvertip · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

Something is seriously wrong here. I don't think you could "pour" 17 gallons of fuel through that engine in 2 miles. 30 MPH is 1/2 mile per minute or 8 gallons per minute based on your numbers. That amounts to 480 gallons per hour and totally out the relm of reason. The jets in the carbs cannot flow that much fuel.

Haffiman · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

How did you measure the 17 Gal's???

Haffiman · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

When checking your anti siphon valve, check the tank ventilation hose at the same time. If hanging down in a U with lowest point below tank top, it might create a problem as well. No only will it create a vacuum, but might give a wrong indication of 'full tank' when filling up as pressure might build up indicating full tank.

N1NE1 · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

i measured with the flowscan and my other fuel gauge, i am positive it used 17 gallons. its shocking to me too. its always used alot of gas but not this much. i have to be over 20mph to plane out at 4000rpms. going to run me broke

Haffiman · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

Not even sure if the VRO has that kind of capacity?? Sure you are not reading liters?
20 Gal/hour at WOT ought to be the max of what may go through that engine and even that on the high side.

Silvertip · Jul 7, 2012

Re: Johnson 200 fuel/oil consumption

A fuel gauge is probably the least accurate way to measure fuel consumption. The flow scan is obviously not calibrated correctly or it is inaccurate as well. Even if you were reading liters instead of gallons, that's still well over 100 gallons/hour and totally impossible. I suggest you hook the fuel line up to a standard 6 gallon portable tank and run that tank full of fuel. If the consumption rate is as you said, the tank would be empty almost before you left the dock.

N1NE1 · Jul 8, 2012

Re: Johnson 200 fuel/oil consumption

It sounds crazy but i know i use that much because i keep a fuel log of what i use each time i go out and once a week i fill it back up, there is no doubt. it is possible, my bank account tells me so. Im headed back down this week to see what i can find

N1NE1 · Jul 8, 2012

Re: Johnson 200 fuel/oil consumption

i just measured the distance and it comes to 3.5 miles not 2 but its still insane

Silvertip · Jul 8, 2012

Re: Johnson 200 fuel/oil consumption

OK -- so now the fuel consumption in your example drops to 240 gallons per hour (ignoring the .5 mile difference between 3.5 and 4 which would be double the distance). Your engine cannot possibly run and present tan spark plug coloration buring that quantity of fuel. I seriously doubt it would even idle and if it did, the stench of "singed" fuel would be overpowering and the fuel slick on the water would draw the attention of the water police. For heavens sake don't smoke on or around this boat. I really think you are way off on miles, fuel use. Sorry -- but that engine cannot consume that much fuel. I'm not certain if that engine has the red lever on the primer solenoid but if it does, make sure it is set in the AUTO position -- not the MANUAL position.

N1NE1 · Jul 8, 2012

Re: Johnson 200 fuel/oil consumption

i know it sounds completely insane but im not posting this for no reason, You doubt the consumption, come take it for a ride.yes it does have the red lever on the primer solenoid, i am going down again this week and going to run it with a seperate 12gal tank to compare all gauges and check theres no leak and my 2 seperate gauges arent off. its always been bad on gas but its been getting worse. compression is from 93-96 on all cyl. i have gone 12-15 miles in the past to a few reefs and used 25gal all day. i will get back again once i run the 12gal tank

N1NE1 · Jul 11, 2012

Re: Johnson 200 fuel/oil consumption

I took down a 6 gallon tank and hooked it up before the floscan reader so i could compare and the gauge is dead on. I took out the plugs before i started it up and they were wet since the last time i used it when i posted this thread. I think its time to put the gas guzzler up for sale.....

archcycle · Jul 11, 2012

Re: Johnson 200 fuel/oil consumption

Forget the gauge for the moment and forget the floscan for a moment. Both of those can be dead on without telling where the gas goes after it leaves the tank. Flowing one gallon of gas does not mean 1 gallon of gas reached the motor.

How far did you make it on the 6 gallon tank before it ran out? I'd be interested to see what you get if you bypass Everything. Run a fuel line from the portable tank to the fuel pump. If it still hogs fuel then run it with the cowling off and see where the fuel is ending up. If it is still not obvious then remove the air silencer and run it. Don't worry about running lean in that case because if it is is sending 240GPH through the carbs then you WON'T have a lean problem from running no silencer

Chris1956 · Jul 11, 2012

Re: Johnson 200 fuel/oil consumption

Maybe most of the fuel ends up in the bilge and gets pumped overboard? The bilge pump is about the only pump that can handle that much liquid.

N1NE1 · Jul 11, 2012

Re: Johnson 200 fuel/oil consumption

Its definetly making it to the motor without leaking aywhere, i made it 30 minutes between 6-7 mph through a no wake zone. used half the tank then turned back. The motor is without a doubt small for the boat. The only thing i did not bypass yesterday was the floscan sensor and a filter.

archcycle · Jul 12, 2012

Re: Johnson 200 fuel/oil consumption

Do you mean half of the 6 gallon tank and turned around?

krimi · Jul 12, 2012

Re: Johnson 200 fuel/oil consumption

Thats around 1 mpg which is about right for a non plane plow with a 6 gallon tank. At best you will get 2 mpg with that rig.

daselbee · Jul 12, 2012

Re: Johnson 200 fuel/oil consumption

I get 2 mpg running a mix of idle, mid-throttle (just up on plane, 3300 RPM) and a few WOT runs.
Averages out to 2 MPG.

Oh yeah, 200 1996.

Johnson 200 fuel/oil consumption

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