GT 200 surging

[stratos976]

I have a 1991 Johnson GT 200 m/n VJ200SLEID s/n 02600222.

The last two time's I took it out i've noticed it surging, not as much if I'm cruising but when running wide open, it'll will surge(gain 6-700r's) from about 5100 up to 5700 then back down.

I just added a spin on water seperator/ fuel filter, new primer bulb, and removed the inline filter @ the motor.

Do you guys think I got some junk in the carbs or could it be something else??

[v8etr]

Sound to me like a lean surge.

[smallscalepilot]

I have been chasing this same issue. From what I have read and been told, make sure the air box still has it's guts in it. If it does not, it needs to have 74D jets in the carb. The earlier 200GTs came this way and most people removed them guts on the later models. You can remove a main jet through the brass plug on the float bowl. I have been told this was a very popular mod that will cause bad lean runs.

I unfortunatly think I found my problem a little too late. I tore up the bottom port side piston yesterday and think it might be the lower crank seal. I'll have to do some more research around here.

[stratos976]

all guts are still in the airbox, and I'm not sure it has to do with wrong jets. I've never had this problem before, I just noticed it after installing the fuel filter/ water seperator. Could it be causing it???

[smallscalepilot]

I didn't know if this motor was new to you, or just a new problem. I chased a few things and found that my primer bulb check valve was not working and would not hold a prime. I replaced it and it ran a whole lot better, until one cylinder ran lean. Let me know if what you find...

[ChampioNman]

Did you replace the primer bulb with a BRP primer bulb? Many after market bulbs do not afford fuel flow or other properties to the manufacturers specs. This is why we specify only BRP/OMC replacement parts.

[stratos976]

no . I will get one from the local shop this week, what other things could I check while I'm changing this out??

[ChampioNman]

If accessible I would replace the elbow at the fuel tank or knock out he anti-siphon bb in the elbow.

[stratos976]

Thanks I will.
Also this may be dumb but does it matter where the primer bulb is, weather its between the three way valve (my boat has dual 24 gal tanks)and the H2O seperator or between seperator and the engine?? Does that question even make sense ?

[ChampioNman]

Yes it makes sense. You want your primer bulb as close to the motor and as vertical as possible. They have internal check valves. The check valves in the tank have a tendency to hang and that is why you drive them out to make sure the fuel flow is unrestricted.

[stratos976]

Thank you .I'll post to let you know how it goes

[ChampioNman]

Did the surge start after you added the filter/seperator or was it always there? This is a need to know ?

[stratos976]

It started after I added it. I've never had that problem before, also when I put that in I replaced the primer bulb.

The seperator is BRP/OMC brand I've had it for awhile and just got around to putting it in.

[ChampioNman]

Make sure the fuel hoses follow the arrows on the separator and the hoses are clamped tight.

[stratos976]

OK....fuel hoses are installed correct direction, got BRP/OMC bulb and located it in fuel line near motor instead if in bilge area, all clamps are tight.

I drained each bowl just incase there was water in a carb, actually found a BB size amount in top carb on starboard side, thought that may have been part of problem... ran boat today and still has surge at high speed....what can it be???

Does the entire Filter have to be above the tanks, I have it mounted w/ top of the filter housing even w/ the top of the tank?? could it be possible that at high fuel flow its trying to empty the filter??

[ChampioNman]

When you're out running again, and it starts to surge hit the choke and see if it picks up or bogs. If it does you have a delivery issue if it doesn't then you have an electrical issue. Does the new bulb have yellow ends? that is a 3/8" primer bulb the 5/16" are black. The placement of the separator sounds correct.

[stratos976]

Yes, it is the 3/8 bulb. I'm gonna try and take it out again today and I'll see what happens when I push the choke... I take it if the motor picks up it's delivery and if it bogs it's electrical??

[stratos976]

Ok finally got to take boat back out! The first run down river motor started to surge, so I pushed choke in and could tell the motor seemed to be loading up, let off choke and ran a little further. I was also checking j/p height so did a few holeshots & short runs.

Decided to do another WO run...no surge... ran twice the distance as first run and neverhad the motor surge....stopped and fished for awhile, ran back to ramp never had motor surge again???

I'm confused , this was the longest WO runs I've done this year, maybe just trash? Should I be worried??

[DIXIEDOG]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stratos976 &raquo;</TD></TR><TR><TD CLASS="quote">

I just added a spin on water seperator/ fuel filter, new primer bulb, and removed the inline filter @ the motor.

</TD></TR></TABLE>

Is it recommended to remove your inline filter when you install a separator? I left my inline filter on the engine, I didn't think the spin on filter was a fine enough filter. I'm sure the experts will chime in on that, I'm just thinking out loud I guess

[Scrapper]

This is just a shot in the dark...but the GT's have the 35amp charging circuit...what is your volt meter saying?? When the regulator/rectifier starts going south you will get irregular readings on your voltmeter. This will cause powerpacks to go crazy. I had the same problem on my GT150. Would cause a WOT surge...almost like you drop a cylinder. If you do not get anything with the fuel...test the regulator...it sits on top of the block in between the two heads. It is water cooled...you have to take the flywheel off to get it off I believe.

Just a thought.