So I am getting almost finished with this bike mechanically and all that is really left is electrical wiring/rewiring of the turn signals and battery relocation along with painting the tank and seat. But I am super intimidated with tweaking the carbs. I am going to use stock headers with emgo dunstall replicas and mikes xs air filters. Does anyone know what I need to swap out? I tried running it before to see if the engine is proper and it would never idle without full choke and goes really high in rpms. Any help is appreciated, I would really want to get hands on with this to save money and gain experience in the long run.

So I am getting almost finished with this bike mechanically and all that is really left is electrical wiring/rewiring of the turn signals and battery relocation along with painting the tank and seat. But I am super intimidated with tweaking the carbs. I am going to use stock headers with emgo dunstall replicas and mikes xs air filters. Does anyone know what I need to swap out? I tried running it before to see if the engine is proper and it would never idle without full choke and goes really high in rpms. Any help is appreciated, I would really want to get hands on with this to save money and gain experience in the long run.

It should idle ok with stock pilot jets, try upping the mains to next size but they really affect the engine from 3 k revs so you may have an air leak somewhere.

have you checked the intake manifold for leaks and all vacuum take offs are secure?

float height ok?

carb really clean?

did you check this site out?

I can see some cracks on the intake boots and is there more than one vacuum? I only saw one and I plugged that up. What is the right float height? and does it apply to all stock/modded bikes?

take a look at the "xs400 links" sticky at the top of the forum, there are links to manuals that should have the float height.

oh yes i know that, in fact I even have a hard copy of the clymer manual. But I was just wondering if the float height needed to be different since its I am getting airpods and new exhaust mufflers.

oh yes i know that, in fact I even have a hard copy of the clymer manual. But I was just wondering if the float height needed to be different since its I am getting airpods and new exhaust mufflers.

Oh, sorry for the misunderstanding on my part. I may be completely wrong here, but i don't think the float height will need to change from stock. in my limited knowledge of how carbs work, i believe the floats are just keeping the fuel level in the bowl at a constant level. The jets take care of all the changes you need to make to accommodate the change in air flow. I'll let someone verify that i am correct though.