Float Settings / Carb Settings 1998 225 Venom

Hey y'all,

Thanks for any help in advance.

I bought a 1999 Sprint F/S 207 w/ a 1998 225 Johnson Venom a couple of months ago. Shortly after I bought it I started having trouble taking off. The Motor would bog down when I was trying to take off quickly ie pulling a tube/skier. I would have to give a little throttle back off, then some more throttle then back off then I could go full throttle. Also, associtated w/ this was a rough idle after the engine warmed up then was turned off for a few minutes. The problem has continued to get worse to the point the motor floods and won't even start. First start it will bust right off idle up then idle down, down, down until it quits. If I can keep it running long enough to get it up to full throttle is runs like a bat out of H**l.

I pulled the induction manifold and noticed fuel was running all over the place. The induction manifold is just coated w/ gas and oil on the inside. I've put new plugs in it; but I still need to adjust the carbs.

Motor is a 1998 225 Johnson Venom. Model# J225STLECS Serial: G 04510224
Carbs were made in Mexico 3/26/1998 #439510 <- this # is from a sticker on the carb.. turns out it's different on 3 of the carbs.


What are the adjustment settings on the floats. Can they become saturated? How much should they weigh? Mine weigh .2 oz.

Also where should the indicator be placed for the automatic/electric choke? The indicator on the valve stem will point from 12 o'clock to 6 o'clock in a clockwise motion.

Any other ideas on what is causing this flooding would be appreciated.

Thanks again. <br /><br />
Modified by Sheave at 1:26 PM 8/5/2010


Modified by Sheave at 1:33 PM 8/11/2010

Still having issues.

What I have done:
1. New plugs : NGK R gapped to .030
2. Pulled all the floats and leveled them even. Turn upside down and cannot blow through needle valve.

What's still going on:
1. I can flood this motor by squeezing the bulb 3X. Oddly, the fuel runs out of the throttle plate where the throttle bar goes through the plate instead of the weep holes. Motor can be hard to start at times if I squeeze the bulb to much.

2. The biggest issue is loss of power after the engine warms up. Allow me to explain. I can run across the lake to my first fishing hole. Turn the motor off and fish for a while. Then I fire the motor up w/o problems. Then, when I engage the throttle to take off, if I give it to much throttle it will die. Start it back up. Give it a little throttle at a time it will finally go. But just the slightest to much throttle and it will die unless I can get it back to neutral real quick like. Also, trying to push the boat on the trailer is futile. The engine will just die. I have to use the winch to pull it onto the trailer.

3. Another thing I noticed is the Induction manifold is becoming soaked w/ gas/oil mixture on the inside. I cleaned it up real good but it quickly became soaked again.

4. All of the new plugs seem to have the same color ( a coco brown color).

Could I have a power pack issue? I'm guessing this motor has six(One for each cylinder) each wire going to the corresponding plug.

Sounds like you have sticking floats, for one thing, causing the flooding. http://www.bassboatcentral.com/smileys/USA1.gif

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Mr Limpet &raquo;</td></tr><tr><td class="quote">Sounds like you have sticking floats, for one thing, causing the flooding. http://www.bassboatcentral.com/smileys/USA1.gif </td></tr></table>

Should I be able to squeeze the fuel bulb until it gets hard? The one on the boat never does; it just starts to flood over.

Yes. If pumping the bulb causes gas to pour out of the carbs, then it sounds like the floats are stuck open with trash. Based on your questions, I would get professional help if I were you. These motors are not complicated but they require a great deal of know how to get them to run correctly and reliably. Six carbs have to open simultaneously, feeding an equally metered fuel/air mixture while advancing the ignition at @ 5600 RPM. DO you want to take a chance with that? Ask some of your boating friends who is a good mechanic near you. If cash is tight, sometimes you'll find a good dealership mechanic who will do a Saturday house call on the side.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Mr Limpet &raquo;</td></tr><tr><td class="quote">DO you want to take a chance with that? </td></tr></table>

Yes, Honestly I do. I've had several race engines in the past, I have completed several overhauls on "car" engines. I routinely perform maintenance on diesel motors. And I've worked on a few lawnmowers. I have a good assortment of tools too.

I don't, however, have much experience w/ 2 stroke motors. Therefore I'm intimidated to just jump in and take things apart. That's why I'm asking if anyone can point me in the right direction. I don't think this is a major issue, I think it's more of a tunning issue.

Thanks for your input though.

Loose the NGK's pronto. Champion QL78YC or QL82YC gapped at .030. You have a sticking needle seat. Yes bulb should get hard once the system is primed. no fuel run out.
Inverted carb level, float level +/- 1/32". Do not adjust arm adjust the tab behind the arm. Also make sure that the clip for the needle valve is on the port side of the carb body, it could hang other wise. No clear washer under needle seat.

Thanks ChampioNman!! I'll get right on those plugs http://www.bassboatcentral.com/smileys/wink.gif

What about the electric choke on the side? I've been concerned that maybe something was sticking on that. It has a adjustment that moves "clockwise" between in the 12 & 6 o'clock position. Is there any kinda needle there could be sticking? Currently I have the "red arrow indicator" pointed down. I have no idea what it does though.

That is your primer solenoid. If it is up your choke won't work. Down at 6 O'clock when you press in on the key in the on position you will hear an audible click. The primer is working. It shoots gas behind the carbs into the intake manifold to help richen the fuel mixture on cold starts.

Could this be the root of my problem? Can it get stuck in the "Open Position". Two reasons I ask?

1. The fuel isn't coming out the weep holes. It's coming out the throttle plate. The motor is level.

2. The prior owner of the boat ran "Ethanol" fuel exclusively. My experience is that Ethanol fuel dries out diaphragms, seals, "o"rings, and starts turning bad at about 30 days, even w/ fuel stabilizer. Personally, I run good ol' 100% petroleum fuel. But the boat has done this since I have owned it. It didn't do this when I took it for the test run. http://www.bassboatcentral.com/smileys/embarassed.gif

Did you use BRP carb kits? Or aftermarket kits? Big difference in quality. Check the bowls for warpage and replace if needed.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by ChampioNman &raquo;</td></tr><tr><td class="quote">Did you use BRP carb kits? Or aftermarket kits? Big difference in quality. Check the bowls for warpage and replace if needed. </td></tr></table>

BRP?? I did't put in new carb kits. I pulled all the bowls and adjusted the floats. Not that any were way out of adjustment. Mainly I was looking for trash in the needle seat. I found a little on the middle carb port side. This was also the only carb leaking out the weep hole.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Sheave &raquo;</td></tr><tr><td class="quote">Could this be the root of my problem? </td></tr></table>

I pulled the 2 hoses that go out to the throttle plate & plugged the nipples w/ my fingers. I then pumped up the "Bulb Primer" which stiffened right up and got hard. No fuel is running out now :) I tried this w/ the arrow in the up and down position. Same result.

I'm going to plug off these hoses and nipples and take it for a test run sometime tomorrow. I'll let you know what I find out.

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by ChampioNman &raquo;</td></tr><tr><td class="quote">Champion QL78YC or QL82YC gapped at .030. </td></tr></table>

QL78YC is what I pulled outta this motor. The negative electrode was so eat up the plugs gap was at .450 to .500 ? According to the parts guide I looked at, this motor requires a "Racing" plug. The NGK 3133 (BPZ8HS-10) was the only plug I could find to meet this requirement & the QL78YC's were not the proper replacement plug. I had to special order the NGK's too, took 3 days. Keep in mind, I live in a small town.

Any info you have concerning this would be most appreciated b/c the QL78YC's are about $3.00 less per plug.

Update here. I was talking to a friend. He told me to pull out on the red indicator on the primer pump. and then turn it. I did this and now the fuel is not bypassing the primer. I'll get someone to hold the key in and I'll check to see if it opens up.

championman suggested the champion plugs to me as well. Trust me it does make a difference. my 00 looper had no issues with the ngk to start then it became a constant problem. Same issue you had with trailering and idleing after it was warm. I put the champions in and it has been flawless.

Well the flooding is fixed. But still the same hesitation trying to get it going. I give it throttle and it almost dies. I have to just keep messing w/ it. Give it a little throttle. then a little more. Most of the time it just dies. Pumping the bulb primer seems to help now. In fact if I don't the motor won't get above "No Wake" speeds. Finally, It will get past that certain spot or something and it will take off. Run's like a bat outta hell once I get going. If I keep it going I'm fine. But, if I slow down and idle around for a couple of minutes, or stop to fish, the entire process starts over again. And by process, I mean the boat may die 10 or 20 times before I can get it going strong again.

Now I'm suspecting the fuel pump? Any ideas?

After reading another post, I thought I might add that I have been running Lucas gas treatment. Could this be causing any problems?


Modified by Sheave at 3:27 PM 8/12/2010

I was wondering if you ever fixed your problem. .im having the same issue. ..and I did unplug the throttle plunger for cutting the motor down to 3 cylinders. ..