My bike trying to idle.

xs400neophite

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Hey whats up yammies?!

Can you guys listen to this video and tell me what you hear?

My friend at work says it sounds like its missing. If you listen carefully ,you can hear more of a pahpahpah on the right side and kind of a puhpuhpuh and the leftside.I was wondering if maybe the valve are sticking on the right side thus causing missing and higher temp(blue pipe) on the right side.Let me know what you think and any checks I can do.Does it sound like its running on one cylinder?


 
The easy way to determine if it's running on one cylinder is to touch the headers. Be fast or wear some gloves though; it gets really, really hot.

It sounds like a low idle; mine is turned up a bit. What's it idling at?
 
Hey bc what is up? Looks like your busy with the 'Re-build' cool as heck!! I dont want to sound like a newb but I dont know where the idle adjustment is! I know I have a sync screw but the air/gas mixture screws are preset on my xs '79...what am I missing? If I look at the tach ...its just under 1000? IDK?
 
800 to 1200 is probably fine. If it sounds like it's about to die you can turn it up a little. The idle rpm screw is between the carbs on the air filter side.
 
Disclosure: I have the xs400J (the DOHC engine).

Sometimes mine can sound pretty damn similar when the idle is too low. The manual for the DOHC says its 1200-1500. Below that and it hesitates/doesn't wanna go.

So turn up the idle some to around 1300 and see how it runs.
 
Thanks guys! Will do.

I gapped the points today and will static time it later. Thanks for the video link 'Houghmade' very helpful.

I am still concerned with maybe the valve,guides,seat.. been sticky or stuck in that right side.Some friends at work say it just needs to be rode and work that stuff through. It did sit for 28 years. After such a long time some stuff might gunk up. Added MMO to the oil to try and loosten some of that stuff. If a guide is stuck or a leak developed, this will have to be rebuilt? I just worry running it and about all that heat that right combustion chamber.

Thanks guys for your input and I will keep you posted :thumbsup:
 
I timed the bike today and it was off on the right side. The gap was tight too. Also the bike was firing on the 'RT' mark more than the 'RF' mark. Adjusted so my little check light turned on at the 'RF' mark.Hate it when my friends are right.....it was missing on that right side.
The right side adjustment screws were abused. I had to be careful with them and push as I turned to tighten them. Need to get some new ones for next time.I really hope that helps out with that side being off.

I also got into the petcock today. Drained the gas and took apart the petcock. Found someone had been there before me and tightened the face plate with the gasket askew.(see the pics) I turned the gasket over and hope it holds.

I also took apart the little diaphram in the back of the petcock. Really nothing that can go wrong back there. I carefully put it back together and sucked on the little vacuum hose and also blew into it. Heard it working. Hope it works...we'll see tommorow. When I sucked on the little vacuum hose, gas would come through the petcock on the 'on' position. We shall see tomorrow!!
 

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Instead of spending $ on MMO,try ATF[automatic transmission fluid]in the gas and oil.It's the same thing and is a good lube.You can put about 1 ounce per gallon in the gas,and about the same per quart in the engine to clean and loosen up gunk in the motor,and it's safer than motor flush before changing your oil. lha:bike:
 
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