1997 challenger wont tach past 4500

[herbbrock]

New to jet boats.
The boat has been sitting since 2007. drained all fuel and added new fuel. Unable to plane, the engine won't go past 4500 rpm. Any Idea's? I tried to adjust the throttle cable. I still can't seem to get the butterflys to open all the way at full throttle. is this the problem? Any help would be great. New plugs have been installed. Should there be white smoke from exhaust? It's not a lot, but always there. The plugs aren't getting fouled.

 

[timmyboy76]

hey herb, need to figure out why the "throttle" aint opening fully, also, pull the "lever" assy's outta boat, make surethe nuetral safety switch aint stuck, and for white smoke, could be combination of the 2-stroke mix and steam from water in exhaust..

 

[herbbrock]

Safety switch first thing I checked, Ok.
Water in exhaust from where? Head gasket?
Do you think the butterflys not opening completely is my planeing problem? They open 75% at full throttle setting.

 

[timmyboy76]

Water in exhaust, from the waters' cooling route. It dumps/exits at exhaust flange and the "lines" that attach to pipe.

Would think thats why it aint planing. If even running great, Hold throttle at 1/2 go, and boat will sit there any "wanna" plane, but wont. also bad wear ring will not let plane, but wont "hold back" rpms.

NeeD to find the reason the "throw" in throttle aint going W.O.T.

 

[phough5757]

Lever assembly

I had Mine out yesterday and noticed a bracket that holds the casing was bent. I straitened it out and now both throttle plates are the same.
Your cable could also be stretched. Adjust the case length at either end.

 

[herbbrock]

Thanks. The bracket was bent. Now the butterflys open completely. Still 4500 rpm only. 1997 challenger, any ideas?

 

[dukeschuff]

mines doing the same thing only it will rev to 8000 when in fwd or rev. just not nuetral

 

[phough5757]

I'm thinking neutral switch.

On the direction selector is a switch that limits engine RPM.
I'd look there next. Good luck!