High HP engines stalling when placed in gear.
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High HP engines stalling when placed in gear.
I have twin 1000's, Arneson 8'ss, 17.5 x 32 five blade props. And have an issue with stalling when placing trannies in gear. To keep from stalling I have to attempt to slightly jiggle the throttles (goose) when shifting.
My friend has a 43 Nortec with 1250's and # 6's. He noticed me having problems with the above issue. We both are running Huber's. He said he removed the tranny valves and slightly machined the opening of each valve so the fluid would ease instead of thrusting the tranny into gear. This eliminated the stalling issue.
Any comments on this procedure?
My friend has a 43 Nortec with 1250's and # 6's. He noticed me having problems with the above issue. We both are running Huber's. He said he removed the tranny valves and slightly machined the opening of each valve so the fluid would ease instead of thrusting the tranny into gear. This eliminated the stalling issue.
Any comments on this procedure?
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Re: High HP engines stalling when placed in gear.
I am having the same problem on one of my engines.If I play with the throttles it will not stall.It was rebuilt(do to a blow up) and now it stalls when put into gear.The other is fine.I am running twin Disc trannys with Kaama drives.Would not do this before the rebuild.SBC chevy with Mega Blowers.785hp.I would like to know the problem.
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Re: High HP engines stalling when placed in gear.
If you run centrifugal advance in the distributor, make sure you use stiff springs to keep timing from floating around under 1600rpm.
The valve mod in the tranny sounds like a good fix. Another fix would be to install a restrictor solenoid to drop line pressure around the docks (like the bigboys do with "trolling valves" on sportfish boats).
The valve mod in the tranny sounds like a good fix. Another fix would be to install a restrictor solenoid to drop line pressure around the docks (like the bigboys do with "trolling valves" on sportfish boats).
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Re: High HP engines stalling when placed in gear.
I have two friends who have blown the trannies trying to "feather " the fuel once shifted into gear. If high r's are created before or while shifting into gear the bands will not take the load. Especially in reverse, there are only two bands. Chi Town found that one out the hard way. The fuel can only be feathered once it is in gear(immediately). Too much then in a tight situation and you are launching.
This is only an issue when in a tight space or docking situation. The only thing I can do now is point it in the right direction, get close and start throwing lines.
This is only an issue when in a tight space or docking situation. The only thing I can do now is point it in the right direction, get close and start throwing lines.
Last edited by expresscat39; 09-05-2004 at 02:42 PM.
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Re: High HP engines stalling when placed in gear.
I feel your pain,manuevering with a single surface drive is about impossible.I have my distributor locked out at 34 degrees.I can have the boat out of the water running on a hose and it works fine.It is only when there is a load on the props.
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Re: High HP engines stalling when placed in gear.
The engine may be stalling because it is running lean on the idle circuit. If it is a carbbed motor try backing out the mixture screws 1/4 to 1/2 turn and see what happens. Chances are the motor will RPM way down, but the extra fuel will keep it running until you can coax it with the stick. Unless EFI this is the nature of the beast!!!
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Re: High HP engines stalling when placed in gear.
Running 1071's with dominators.
We have adjusted the carbs.
Anybody know anything about altering the tranny valves so it slightly spools the drive before full engagement??
We have adjusted the carbs.
Anybody know anything about altering the tranny valves so it slightly spools the drive before full engagement??
#10
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Re: High HP engines stalling when placed in gear.
Ex39,
I have been told about step down kits including solenoids that kick the rpms up when shifting on big HP engines. Sterling provides this on their engines. Tres has done several of these conversions. They run about $1,200 per engine. I am looking into this myself. I have the engines idling very high now to avoid turning off during shifting, however, I hear these kits work very well.
CMW,
Is this what you are referring to as well?
I have been told about step down kits including solenoids that kick the rpms up when shifting on big HP engines. Sterling provides this on their engines. Tres has done several of these conversions. They run about $1,200 per engine. I am looking into this myself. I have the engines idling very high now to avoid turning off during shifting, however, I hear these kits work very well.
CMW,
Is this what you are referring to as well?