Greetings, I am bringing back to life this XS400. It has good compression and I have completely rebuilt the carbs. from the first start up I could not get it to idle. I pulled the carbs and double checked the settings---they are ok. I even bought new carb mounting boots. (points and timing are set properly) QUESTION: Do these carbs need the air filters on to create some back pressure??? thanks, Lew
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1978 XS400 Carburetor problem---HELP
- Thread starter Lew11
- Start date
Yes, you need the filters to tune, but when you say "...the settings..they are ok"- what do you mean? What did you adjust and what is it set to. There are some "factory" settings that do not work that well. For instance, the factory idle mixture setting is way too lean and if you add no filters to that, I would not at all be surprised if it did not idle.
Thanks for responding. I just checked my book and cannot find anything on idle mixture adjustment. As I recall I used out one and a half turns. (I have always restored Hondas before. I bought three XS400s with some Honda cB700s. This is my first Yamaha) QUESTION: What setting do you recommend for the idle mixture settings?? Thanks, Lew
OliverB
XS400 Junkie
For the idle air mix screws, go to 3 - 3.5 full turns out.
What he said. I started at 3 turns out and it idled well most of the time and started well, but when warm, it would die every once in a while. I'm at 3.75 turns now and all is good. Get the filters on and open the mixture and let us know where it's at.
