timmersuds

I am having an isue with a Blackjack 55. It has had about 3 tanks of gas run through it so it is relatively new.

All of a sudden, it is running at about 50% power. It starts and runs fine but top speed appears to be about 50 percent.

Any suggestions would be appreciated.

Thanks

PEERPSI

Clutch?

timmersuds

I've read that clutch problems are typical with this boat. What are the symptons of a bad clutch?
Thanks

Dockman

Strut has moved? Throttle cable has slipped?

Dockman

3 Tanks of gas! Clutch is most likely not shot yet?

MsDarla

Most likely throttle cable.
Common issue. [&:]

PEERPSI

Make sure your throttle cable is opening the carb all the way. My clutch failed after about 3 tanks so it's a real possibility. Problem with there clutches is the standoffs. They are not equal length, must be cut by hand? Result is the clutch axis is not inline with the crankshaft axis. The brazed ferrule to clutch bell doesn't help either.

Doubtful that strut settings would cause it to slow by 50%. A few miles an hour sure. You'd also notice some severe handling problems if it was way off.

timmersuds

It appears that the throttle cable is properly adjusted (as far as I can tell).

When you press the throttle lever on the remote the cable opens all the way to the stop point.

Is there a way to adjust the stop point to allow it to open further?

Thanks

Dockman

Does your prop shaft spin freely? If the strut is way deep in the water and negative trim it will kill the enging rpm's. Check you orings in the pipe and check your needle setting? Could be the hsn needle has moved out and made it rich.

PEERPSI

[/quote]

It appears that the throttle cable is properly adjusted (as far as I can tell).

When you press the throttle lever on the remote the cable opens all the way to the stop point.

Is there a way to adjust the stop point to allow it to open further?

Thanks


[/quote]
If the cable is opening it all the way to the stop, then no. If you hold the prop shaft and try turning the clutch bell does the clutch bell move at all? You may also want to pull the bell off and check to see both shoes are there and working. Carb settings for the stock Zenoah are 1 5/8 on the low and 1 on the high. Turning the low in is a quick way to leaning out your motor an overheating it. For the most part only small adjustments on the high should be needed. Run it full out and shut it down right away. Then check the spark plug. If it's nice and clean with no deposit, too lean. Tan or light brown is what you're looking for. Remember it's a two stroke with oil in the fuel. Therefore lean means no lubrication.