Carb jet sizes

[cvlngineer]

Re: Carb jet sizes

John,<br /><br />Gotcha! Thanks a bunch for the information. <br /><br />As far as WOT goes, The cam will not advance the carbs to a fully open position. When I have the controls at full throttle, and I walk back to the motor, I can push the roller and thus the throttle plates open further, about 3/8 to 1/2 inch or so more movement of the roller. Is this a problem?<br /><br />Thanks,<br />cvlngineer

 

[jegervais]

Re: Carb jet sizes

When the throttle handle is at WOT, either remove the cover from the air box and see it the throttle plates are horizontal (relatively speaking), or look on the port side of the carbs, the roll pin on the throttle shafts should be vertical.<br /><br />It is possible to push the roller further, which "bottoms" the throttle plates against the stop. This would restrict air flow thru the venturis, thereby cutting back the flow of fuel from the the hi-speed nozzle. If you were driving the boat out on the water when (if) this occurs, you would notice a loss of power and speed.<br /><br />-John<br /><br />BTW - to add to this line of thought, if the cam is indeed not opening the throttle plates as I described (say only 3/4 to 7/8 of full open), something in the linkage set-up of the motor isn't correct.<br /><br />BTW 2 - Does this motor have an under flywheel distributor with 1 ignition coil, or is it a CD ignition with a timer base and (3) individual ignition coils?

 

[cvlngineer]

Re: Carb jet sizes

John,<br /><br />It is CD ignition, with 3 separate coils. If possible, could you send me a picture of what the linkage and cam is supposed to look like for this engine and carbs? My e-mail address is smithcharlesw at hotmail dot com (use "@" and "." though )<br /><br />I set up the timing the way that you described, and it seemed to help a lot. I can blow lots of water out of my test barrel at idle now! I changed out the shift-shaft seal this afternoon, and I will probably take the boat out to the water tomorrow. I will let you know how it goes.<br /><br />Thanks for your help,<br /><br />cvlngineer

 

[cvlngineer]

Re: Carb jet sizes

^^

 

[cvlngineer]

Re: Carb jet sizes

I took the boat out again today. It performed much better. I putted around close to the boat ramp at about 1000 - 1500 rpm as per break-in instructions. I got in about 1/2 hour on it.<br /><br />I tried to give it a little more gas to see if it was going to bog down, and it did at about 1800 rpm. I was hearing a slight noise with the cowling off, so I cut my trip short and took it to a local shop to let him listen to it, but I could not get it to make the noise again. The guy laughed and said that I was probably just "gun-shy," and I am. I hear all kinds of "ghost" noises from this thing. While at the shop, the owner noticed that the carbs were not opening all the way, so he had me unscrew the cam 3 turns, and loosen and reposition the follower. I cranked it up and put it in gear in the tank. I got it up to about 2000 rpm or so before It threw too much water out. It never bogged down though. It is definitely improving. <br /><br />I am very curious what the noise that I heard was. It sounded a bit like a loose belt on a car engine, but very quiet. I could not hear it at all with the cowl on, and only slightly with it off. <br /><br />cvlngineer

 

[cvlngineer]

Re: Carb jet sizes

^