Converting DT115 to DT140?

[lworley]

Does anyone know anything about converting DT115 to a DT140? From what I have found the only difference is the carbs.

[The Oz]

Conversion 115 to 140

The bore and stroke are the same, weight is the same, but hard to believe the only difference is carbs making a whopping 25 HP difference. Have you investigated whether the carbs for a 140 bolt up directly to the 115 manifold? If so, why not try it?

[jaysonbarn]

Yea try it out when you get a 25hp of extra power at just a small change.

[lworley]

Out of everything that I have researched the only two things that I can find different is the carbs and the plate they bolt to that bolts to the the manifold.. but I cant find one to try out im gona have to buy one.. and I dont want to spend the money if it wont work.

[Peter Devil Ears]

Hi, did you do the mod? Apparently the porting is also different. Did it produce good results if you have done it?

[keakar]

yes it will work but gas milage drops faster then hp increases so be ready for a gas guzzler

i had a 90hp evenrude and the same situation where the 90hp/115hp/135hp were all identicle bore stroke and displacement just as i think you are describing in this case and if so then the only thing you needed to do was replace the carbs and the intake plate should be changed but you can reuse the old plate you just dont get full benefit so you might get 135hp instead of 140.

i saw one guy had modified his plate to fit, he just ground out the opening to match the bigger bore carbs and that worked too

[noelm007]

this sort of thing comes up all the time, there is almost no outboards that have ********g HP that it is "just the carbs" that is the difference (regardless of urban myth) lots of powerheads share a common "family" but in fact there can be and often is, a lot of things that are different, thats why when you replace the carbs, you end up with a rich running crap motor. Even though they SEEM to be the same, most will have different exhaust, different porting in the cylinder (that cant be altered) and all sorts of other small things that make the bigger HP, it has been tried time and time again for years, some know what they are doing and get results, most fail dismaly!