Motor vibration NEED HELP

[justgary]

1. Idle needles way too rich

2. Still dumping fuel (wedge too small)

3. Still dumping fuel (float too high)

Maybe all three. 

[90oldskool]

Plan on adjusting the air flow screws but also found that the electric choke has adjustment as well. Which way should i be going? (carbs are a new thing to me) Page 5 of link . 

http://www.edelbrock.com/automotive/misc/tech-center/install/1000/Performer_Thunder_Carburetors_130815.pdf

Once out of the no wake zone , boat runs fine and have not had this issue unit the colder temp runs. 

Edited March 30, 2016 by 90oldskool

[Woodski]

@90oldskool:  electric choke is pretty easy to adjust, once you loosen the three screws, you can reach down and articulate the linkage to determine which direction to rotate the cover to either add or subtract spring tension, more tension will keep choke closed tighter and longer than less spring tension.  It becomes obvious when you play around with it a bit so if you are rich, loosen the spring tension and you can also see the choke open a bit.  Usually it only takes a notch or two.

[MadMan]

The easiest way to find the problem is to remove the spark arrester look at what's happening.  With the engine off, when you open the throttle from idle you should see gas squirt out from the accelerator pump (you might have to hold the choke open to see this).  If the float level is set too low, causing gas dribble out the secondary booster venturis when the engine is not running, you can see this also.

On previous boats I've had, I just disabled the choke.  I never really go out unless it's warm (>60F) and it's one less thing to go wrong.  After a couple of minutes running, the choke should be open anyway.

[90oldskool]

hate to admit this but the answer was right in front of me the whole time. The power wire to choke was not getting a good connection. Put a new end on, boat fired right off. no pump and no throttle giving !!

Raised the idle to 900 rpm, after the motor temp hit 140. That sounds like the sweet spot, from what ive read , idle should be around 650-700 rpm. So is 900 alright? The motor stubbles if its set around 700 rpm, doesn't die but needle drops down to 550ish them climbs back often. maybe starting to get a bad plug or ready for fresh gas?

[MadMan]

On ‎4‎/‎3‎/‎2016 at 7:44 AM, 90oldskool said:

hate to admit this but the answer was right in front of me the whole time. The power wire to choke was not getting a good connection. Put a new end on, boat fired right off. no pump and no throttle giving !!

Raised the idle to 900 rpm, after the motor temp hit 140. That sounds like the sweet spot, from what ive read , idle should be around 650-700 rpm. So is 900 alright? The motor stubbles if its set around 700 rpm, doesn't die but needle drops down to 550ish them climbs back often. maybe starting to get a bad plug or ready for fresh gas?

Since the choke was always on, I'll bet your plugs look pretty bad.  This could be the cause of your idle trouble.  You could just run it like this for a while and see if it cleans up.

Edited April 4, 2016 by MadMan

[Chatty21VLX]

Pull the plugs and note the color of the tip. White is too lean, black/sooty is too rich, and tan should be a good mixture. Make sure when pulling plugs that you use compressed air to blow debris from around the plug hole before pulling the plugs. You don't want any debris falling into the cylinders.

And I would say just replace them. They're relatively cheap, and should be easy to get to on a direct drive. Be careful not to cross thread or crack the porcelain, and you should be good to go!

[Woodski]

@90oldskool:  You may notice at 900 rpm idle, you will get a rough engagement to the trans.  I would, as suggested above replace the plugs and try to set the idle more in the 650-750 rpm range.

[90oldskool]

So the boat started great in the driveway on the trailer with a water hose . Once getting to the ramp , still had to crank for a few seconds for it to fire . After taking a short ride over to the marina my dads boat is at , starting was a lot more difficult. after about a 2 min ride in the wake zone , the boat died and took a lot to get started. Played with the choke wire and throttle to finally get it fired off . after that started and out of the wake zone , the motor would climb hard to about 3000-3100 and the would stop climbing . stopPed at a restaurant for lunch (about 1 hour and half ) the boat started with giving it 3/4 throttle . once back on the open water , motor climbed to  3700 rpm before i let off , not wanting to hurt anything . With boat out of gear , the motor response fine to the throttle and will hit over 4000 rpm. 

Once I got it home , on the water hose, and clamped the wire connector harder on the choke . boat fired with no throttle and ran smooth . 

I do not know the cause of this hard start on the water but not in the drive . Only thing i can come up with is , the wedge is not great enough on the carb. Once on the water and the bow up in the air , the carb is flooding out still?    going to change out the fuel filter just to eliminate that . When testing in the drive way the boat is siting flat , with no angel. Any other suggestions? 

Edited May 2, 2016 by 90oldskool

[Woodski]

It sounds like you are on either side of optimum fuel mixture, need some additional clues to determine whether too rich or lean.  When it does start, are you giving it more or less actual choke?  Do you have any black smoke when it starts or is running?  It almost sounds like with not enough wedge angle, lack of power to pull to redline you might be dropping the fuel level too low at the front of the carb where most likely the main jets are, so yes it could be an issue depending on the boat angle.  Have you looked at the spark plugs after you run the engine, that will tell you whether lean or rich.  Free revving an engine usually allows it to run up to higher RPM even if the tune is way off as it takes very little power to actually do that.

[90oldskool]

No black smoke , white at first start up but no smoke on addition starts or while running . "playing with choke" was moving the power wire to get better connection . ill Pull some plugs when i swap out the fuel filter and take a copy of photos . I agree with the not enough fuel at front jets do to angle , but a 5 degree wedge was the only thing i could find to fit the edelbrock . found 10 or 12 degree for holly's. Thinking i might order a 2" in spacer , then have a machine shop file down to a 11 degree angle . 

Edited May 2, 2016 by 90oldskool

[90oldskool]

http://vid756.photobucket.com/albums/xx208/varnoldi13/20160402_181740.mp4

@Woodski the link is a video of boat starting in the driveway , ill try to remember to take a video at the next lake run . 

Edited May 3, 2016 by 90oldskool

[Woodski]

To me the video sounds like you are not actually getting all 8 to fire on start up, sounds like a few not kicking in but it is only a video and may be misleading.  Do you have a laser thermometer gun, you can get them at Tractor Supply/Menards/Sams etc and can be a good troubleshooting tool for $14-20.  You can shoot the manifolds, heads and see if there is a temperature variation to help you sort out the issues.  I use it frequently just to check manifold temps side to side, oil temp off the pan, tstat housing temps, etc.

[90oldskool]

@Woodski maybe these videos will load. Found a 12 degree wedge that will fit after a long search , they should come in next week. 

 

 

Edited August 24, 2016 by 90oldskool