mercruiser 165 runs rough when engaging drive

i recently purchased a 19 ft. renken bowrider with a merc 165 ran fine on the hose but when i took it to the lake it would die when engaging drive.i finally got it to engage and move but ran like it was skipping or bogging real bad anybody got any ideas where to start? any help would be greatly appreciated this is my 1st boat band i am not that familiar with thes motors

Re: mercruiser 165 runs rough when engaging drive

Welcome to iBoats.

There's a module that cuts the engine out when shifting. If it's messed up or not adjusted it'll kill the engine when you don't want it to.

Check into the ADULTS ONLY section of this forum for info on a manual for your drive. It will contain the adjustment/check procedure for this issue.

Re: mercruiser 165 runs rough when engaging drive

Another issue that will trigger the interrupter is a bad or stiff short shift cable.
This is the cable that goes from the converter (somewhere on the engine or just behind it) out through the transom mount to the drive.. When this cable gets stiff (needs to be replaced) it puts pressure on the interrupter causing the engine to die or run rough. Usually worse in reverse when this is the case.

Replacing the cable requires removing the drive and the bell housing (on outside of drive) It is not really a do it your self project (unless you have done one) as it requires precise measurements and cutting of the new core wire and careful crimping of the tube and total readjustment of the shifting mechanisim.

Re: mercruiser 165 runs rough when engaging drive

you will see the kill switch to the port side rear of the motor on the transome. have someone shift it into gear under load and the tab on the switch should only move up the "hill" about 1/32 nd of an inch.(the actuator has a valley that the tab sits in to run and a "hill" that it rides up to "kill" the motor when shifted only OUT of gear. Have someone do this so up will see the movement and fully understand the system) if it moves any more it will start to "kill" the motor. go through all the adjustment procrdures and take your time and do it a couple of times because it will seem more confusing then it is. if all this fails remove the drive and check for corrosion on the inside of the shift fork. shift into reverse and remove the end retaining screw in the fork and slide the fork around as much as poss. and lube it up with grease real well. 9 out of 10 times the fork is the problem (NOT THE CABLE) . let us know what you find.

Re: mercruiser 165 runs rough when engaging drive

danond said:

Welcome to iBoats.

There's a module that cuts the engine out when shifting. If it's messed up or not adjusted it'll kill the engine when you don't want it to.

Check into the ADULTS ONLY section of this forum for info on a manual for your drive. It will contain the adjustment/check procedure for this issue.

Click to expand...

It's a module on an OMC, but not on a Mercruiser. It is a simple kill switch (microswitch) mounted in the shift cable mechanism in the back of the motor on the top, that momentarily kills the motor when shifting. These go out of adjustment sometimes, especially if the lower shift cable gets worn, if the adjustment procedure (in the service manual) doesn't work, then you need to replace the lower cable, it's not that hard, but of course the drive has to come off But, I don't think the bellhousing has to?

Re: mercruiser 165 runs rough when engaging drive

thanks guys i will give it a try i ,have downloaded the manual so now i guess it's up to me one more question ;does an inboard motor (pee for lack of a better word) like an outboard motor does? when on the hose water only coming out of the bore of the prop,is this correct? or do i have more issues?

Re: mercruiser 165 runs rough when engaging drive

this is what i think is normal for my 165.



the water comes out in 4 places. the prop, the hole at the ft. of the bullet, and both sides very close to the transom. idle relief ports i think there called. ya can see if you look close by my zinc on the transom shield. more like spits out these holes. my port one is usually more of a mist than the starboard one for some reason. this pic was took right after a new impeller... also note the lack of water coming out from around the muffs. i think a good sign that it's sucking up the water....

Re: mercruiser 165 runs rough when engaging drive

ok got another question . how does this motor cool itself? does it get water from the pump in the foot ?or is it supposed to be a closed loop system? my motor has this model number on sticker mcm 165 serial number is 4940062 .i can't tell from the manual i downloaded but according to this model number all i can find is it is supposed to be (seawater cooled)? i hope i am wrong here,because if i am not there are a few things missing from this motor can someone straighten me out on this one? thanks again and it 's ok to call me ignorant cuz thats what i am on this one