1989 evinrude xp200 back firing thro prop

[mike1]

i had a question, the motor is in good shape the carbs are clean and adjusted according to seloc manual and the motor back fires, but when i manually open the priming system and it gets more gas it run fine and it stops popping, any ideas? Thanks also the ignition is good and the timing is right

[flabum1017]

does it pop and sneeze when it's in the water? Those enginges will do that with no back pressure.

There are a few things that can cause the engine to sneeze/pop. The first would be carbs. Then there's air leaks and carb linkage syncronization. The pop is caused by too lean of a mixture, if this just started happening, then you should start with a cabe rebuild and look for any broken mounting o-rings or gaskets.

[mike1]

thanks for the answer, the carbs have been rebuild and the water pump is new and only the lower unit and a little bit of the midsection is under water but how do i richen the mixture this has fixed jets and i got the motor recently and it has been doing this since i got it i got from a guy that had it sitting in his shed for 5 yrs i have another 200 just like it and im thinking about swaping the carbs and throttle bodies, do the plastic carbs warp over time and get air leaks?

[bigbore]

The o-rings should be re-placed.,air leaks will cause that n u sure the timing is correct?

[mike1]

well the timing is around 8 degrees btdc i think ill need to check again but if it was a timing thing wouldnt it back fire even when there is more gas avaliable from when i use the priming/choknig system because when i open the priming system up to let in more gas it stops popping

[flabum1017]

8 before tdc sounds wrong....I will check the manual tommorrow.

Yes, those carbs can warp. The emulsification tubes in them can rot away, passages can be clogged easily and the o-rings can easily dislodge during assembly. If the engine has been sitting for 5 years, the recirculation passages can give problems as can the VRO pump diaphragms.

Look at the idle and mid jets....the idle jets should be a #35 and the mids should be a #39. If they are put in the wrong place, it can cause a lean pop. The top one is the mid,the bottom one is the idle.

The throttle bodies need to be thouroughly cleaned when the carbs are done as well. The throttle bodies have the idle and mid passages in them.

[baja200merk]

8 before tdc sounds wrong....I will check the manual tommorrow.

Yes, those carbs can warp. The emulsification tubes in them can rot away, passages can be clogged easily and the o-rings can easily dislodge during assembly. If the engine has been sitting for 5 years, the recirculation passages can give problems as can the VRO pump diaphragms.

Look at the idle and mid jets....the idle jets should be a #35 and the mids should be a #39. If they are put in the wrong place, it can cause a lean pop. The top one is the mid,the bottom one is the idle.

The throttle bodies need to be thouroughly cleaned when the carbs are done as well. The throttle bodies have the idle and mid passages in them.

timin timin timin

[Freddie Webb]

Pull the flywheel and make sure the woodruff key is not sheared. Seen this before twice, fuel usually pops thru carbs or intake not the exhaust. Index the flywheel and make sure you don't have a cylinder firing out of order.