Honda Twins banner
1 - 2 of 2 Posts

· Registered
19 Posts
Discussion Starter · #1 ·
Just restored an old CB250k1, got everything up and running, jetted (primary and secondary jets) :???:the carbs to suit aftermarket filters and exhausts (i think they're about right). Runs a treat in neutral, as soon as you put it under load it runs like crap, bogs and misfires and does about every bad thing possible. The spark plugs are running pretty much spot on, not lean or rich! Any help guys? Cheers :???:

· Premium Member
27,090 Posts
What are the compression pressures?.....
An otherwise correct engine can and will run as long as it has some compression (within limits), but in order to do work (move the load weight) it has to have good compression....
Your 250 specs about 150 PSI as the minimum acceptable compression to run properly....170+ is considered the normal amount......

You have not mentioned timing and advance, but that can also affect proper running.....

And lastly, Fuel/air mixture.....No way to know jetting is correct until it runs properly under load.......
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.