1990 force l drive idles but dies when in gear

[ldriveswaper]

I have swapped a 120 l drive into my 90 hp boat
The boat idles good with the odd stumble every few minutes
When I go to put it in gear when in the lake it has no power
Then dies out. 150 psi compression even spark on all cylinders.
Motor was just rebuilt. I have 4 spark plug coils 2 main coil packs for
The ignition. The lower two plug seem to fowl and all plugs seem
Wet. With the muffs it revs but a little rough and can go into gear.
I have not checked the timming yet. Any ideas?

 

[robert301972robert]

Re: 1990 force l drive idles but dies when in gear

You need to check the fuel system. your motor is not getting the proper amount of fuel. wene your motor has no power, Is the primer ball hard or soft. check your filters, and your carb bowls. Clean them if needed. check the filter in the fuel pump. I just got rid of a ldrive with a 120 in it about a week ago. That had the same problem. It turned out to be bad power packs. but that is not to say that is what is wroung with yours. I got rid of the boat because of the out drive. it started to leak water around the center seal on the out drive. they are very hard to find parts for.

 

[emoney]

Re: 1990 force l drive idles but dies when in gear

When's the last time the carbs were cleaned/rebuilt? How's the fuel system up to the tank like Robert mentioned? Venting properly? Is the tank a built-in and have you tried running with a different fuel tank?

 

[ldriveswaper]

Re: 1990 force l drive idles but dies when in gear

Thanks guys I will pull apart the fuel system and check things
Out then post back

 

[SkiDad]

Re: 1990 force l drive idles but dies when in gear

where is your mixture screws at - my 125 had an odd stumble at idle and i found they were set at 2/3 and 3/4 and I set them about 1 turn out and difference is night and day on the idle. But I did have to turn my idle up some too

 

[ldriveswaper]

Re: 1990 force l drive idles but dies when in gear

Finally got a minute to work on the boat today. I noticed a big screw up when I did the motor swap
I left the two stator charging wires disconnect to regulator. I will put in the water
Tommorow and post back the results.

 

[scottmm73]

Re: 1990 force l drive idles but dies when in gear

Most times when the motor idles fine on muffs but dies in the water it relates to a to low idle condition. Try setting idle rpm at 1000 rpms on the muffs this should put idle rpm in forward gear at the prescribed 750-850 rpm.

 

[jerryjerry05]

Re: 1990 force l drive idles but dies when in gear

If the wires don't make the difference.
Try swapping the packs.
The carbs leave at 1 turn out.
Clean carbs.
Check the fuel pump?
Water in the gas?

 

[ldriveswaper]

Re: 1990 force l drive idles but dies when in gear

Test the boat today....... It worked great! Jumps right up on plane and runs quite nice..... The steering has some resistance from the exhaust hose. Speedo says around 35 to 40 mph. Does that sound right? I will check it with gps this weekend. Thanks for all the help. Project 90 l drive to 120 l drive a success.

 

[jerryjerry05]

Re: 1990 force l drive idles but dies when in gear

YEA!!!! Good for YOU!!!

Glad it's working.
Now where are the air screw set at???
Not set right,your gonna be swapping powerheads again????
I'd hate to see any problems.

 

[ldriveswaper]

Re: 1990 force l drive idles but dies when in gear

I checked the air screws... I had them at 1/2 turn out. I moved them to 1 turn out. I will tests this weekend. I hope I dont look like an idiot at the boat launch lol. I think they were at 3/4 turns out why I got them but I had moved them when doing the previous troubleshooting.

 

[jerryjerry05]

Re: 1990 force l drive idles but dies when in gear

Glad I asked!!!
They can be left at 1 turn out.