120hp exhaust issue

[Pricey474]

Hi all recently had to change the lower unit on my 94 120hp which has through the prop exhaust to a 89 125hp which is through the snout exhaust now I have exhaust gases escaping into the engine bay which seems to be choking the engine at low rpms also escaping from under leg cowl obviously that lower unit is not meant for my leg but hoping there is some way to cure this has anyone had to deal with this? If so how did you fix?
Cheers Pricey

 

[jerryjerry05]

According to the parts swap on your drive.
​The ones you can direct swap is 90 through 94.
You have pics of the top of the old drive and the new?
There is a rubber exhaust seal that might need to be modified?? on boatsdotnet #69
120 H.P. (1990-1994) Force Outboard 0E000001 THRU 0E093699 GEAR HOUSING Diagram and Parts

 

[Pricey474]

Hi Jerry I moved that rubber seal to the back of the water pump as opposed to the front of pump on 94 in order to separate the exhaust and driveshaft canal but didn't help although not sure how well it sealed also thinking on placing a small plate in the leg to channel it to the snout only. Having trouble uploading pics keeps saying files too large.
Thanks again mate