carb interchangeability 85hp - 140hp

[warrior1]

i have 2 rebuilt carbs from a spare 1978 140hp, the number on the bore is 1 3/16.
can i put these on my 1972 85hp? the bore is 1 on the 85's.
i know they will fit, but will it flood out the engine? or cause driveabillity issues with a bigger bore?
thanks, in advance.

 

[wavrider]

Re: carb interchangeability 85hp - 140hp

I am no expert, a lot of more knowledgeable member's on here will come and tell you exactly what will be the consequences better than I can.

You will be running way rich will cause excessive carbon, idle problems and acceleration also.

Best bet would be to rebuild the carbs for the 85 if they are rebuildeable.
But like I said I am no expert on the issue.

 

[emdsapmgr]

Re: carb interchangeability 85hp - 140hp

If you have patience and are willing to spend the time, you can get them to work. They will bolt right up and can make an improvement to hp and overall performance. You may need to rejet somehwhat, so plan on spending a few weekends checking tach readings and reading spark plugs for color to get the right jet combination. I spent countless hours rejetting a pair of 1 5/16 carbs on a small bore 1972 100 hp. Despite the time spent, it was worth the effort.

 

[iwombat]

Re: carb interchangeability 85hp - 140hp

Just make sure you error on the rich side and not the lean side.

They'll work fine. Do they have choke plates, or do they use a primer solenoid? That could be your only real problem.