Newbie. Any words of advice?

[MikDee]

Re: Newbie. Any words of advice?

Great Find! Good for you, normally I wouldn't worry about any stock cam, but If it's the 290hp/350, I might be a little concerned about overlap on the cam causing water inversion? This might not be an issue if you run thru-hull exhaust? I see It reaches 290hp at 5200rpm, so that's your goal in getting a prop to match, if using that cam. On a boat that old, the 1st thing I'd do is take the antisiphon valve (spring loaded ball check valve) off, and in tank filter, at the fuel tank, and make sure both are clean, and working properly, or replace the valve. Chances are it's got some gunk in it. Then make sure your fuel lines are are still good, & clean, up to your engine, I'm guessing you checked, or changed your fuel filters at the motor? and finally make sure your gas tank vent is clear. Good Luck, Mike

 

[Uraijit]

Re: Newbie. Any words of advice?

I posted another thread with more details as to what I've tried.

http://forums.iboats.com/showthread.php?t=265694

 

[Uraijit]

Re: Newbie. Any words of advice?

Great Find! Good for you, normally I wouldn't worry about any stock cam, but If it's the 290hp/350, I might be a little concerned about overlap on the cam causing water inversion? This might not be an issue if you run thru-hull exhaust? I see It reaches 290hp at 5200rpm, so that's your goal in getting a prop to match, if using that cam. On a boat that old, the 1st thing I'd do is take the antisiphon valve (spring loaded ball check valve) off, and in tank filter, at the fuel tank, and make sure both are clean, and working properly, or replace the valve. Chances are it's got some gunk in it. Then make sure your fuel lines are are still good, & clean, up to your engine, I'm guessing you checked, or changed your fuel filters at the motor? and finally make sure your gas tank vent is clear. Good Luck, Mike

Here's the spec sheet on the cam. Should I be worried?

Camshaft-

Part#3896962

Hydralic Flat tappet

Intake Lift-.450" Exhaust Lift-.460"

Intake Duration @ .050"- 222 Exhaust Duration @.050"- 222

Lobe Seperation-114

 

[MikDee]

Re: Newbie. Any words of advice?

Here's the spec sheet on the cam. Should I be worried?

Camshaft-

Part#3896962

Hydralic Flat tappet

Intake Lift-.450" Exhaust Lift-.460"

Intake Duration @ .050"- 222 Exhaust Duration @.050"- 222

Lobe Seperation-114

No, I certainly don't think so! That is the old orig. equip. 350cu in/350hp Chevy cam (L-79 I believe?). It is great mild hi-perf. cam, very popular, and has been used in various versions of Chevy engines, and probably marine engines as well from the factory. The only difference was in the 350 (gross) hp form, it had 11:0X1 compression, and maybe better carburetion, & more spark advance, you probably have the same heads, & valve sizes, but less compression! You'll have to remember your engine is rated 290 (net) hp, and with modern technology, it's probably pretty close in hp to the old 350 gross hp version

I see you have another thread up, I just checked it, you tried a seperate fuel source then, and no difference?

You didn't say what kind of Distributor you've got? electronic, or points, and if you've checked your total advance? let us know.

So, for now I'd say make sure your accelerator pump is working right, AND the next most important thing with a Qjet is the main vacuum operated/spring loaded power piston that controls the metering rods for the primary venturies (2 barrels). If it gets gummed up, and doesn't work smoothly it's more of an issue then your accelerator pump, and will display similar symptoms, but more severe! It is easy to get to, easy to check, and usually easy to fix, but you have to take off the airhorn (top) of the carb, and it's right there between the 2 barrels, it should move easily up, & down, when compressed (usually operated by engine vacuum, when your fingers aren't pushing it down) and it should rebound easily by the spring it sits on, Or, hit it good with Carb Cleaner (I would normally just take it apart, & clean it good, it's not hard to do) till it's working freely.