Discussion for swapping a KDX motor in a MX frame...
4 posts • Page 1 of 1
- Posts: 4
- Joined: 02:59 pm Nov 13 2017
- Country: USA
I have a very clean 1981 KX 125 I bought sight unseen from a guy in AZ and had it brought down to me in SoCal, it was supposed to have a completely rebuilt engine with a KDX 175 top end. When I got the bike it started easily and sounded very crisp but when the bike was under a load it would miss (not jetting) and it has pretty bad vibration. I came across a 1980 KDX 175 that was pretty rough but was supposed to run good so I swapped that complete motor into the KX. It runs good but is very slow so my guess is it needs to be rebuilt. I also have an 86 KDX 200 motor sitting in my garage that also needs to be gone thru. My goal is to have the ultimate vet race bike, I race 50+ intermediate and I am 165lbs so I love the 125 platform and the bike handles great. I guess my question is should I build one of the 175 engines which is a bolt in or go for the 200 engine and do the necessary fab to fit it? Can the 175 engine be ported and tricked out to make more power? Help
Last edited by redlinegw on 12:22 pm Mar 15 2021, edited 1 time in total.