Hi everyone I am new to here and new to xs650s I just bought my first one. Its a 1980 with 5500 miles on it and looks real good for its age. My problem is it was popping on the right side. I cleaned the carbs and I have stock jets. Now I put in a 45 pilot jet and a 137 main jet. My problem is I cant rev over 5000rpm the only mods are free flowing pipes with short baffels. I had this problem since I bought the bike I thought with the bigger jets it would clear it up.Now I am not sure what to do next should I continue to raise the main jet or should I buy the Canadian needles with the clips and try adjusting that? Or what would you recommend? Sorry for the long post and thanks for the help.
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wont rev past 5000 rpm
- Thread starter smzj4
- Start date
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- Tags
- carburetors
Ironsled77
XS650 GRAND HACK
Search for a carb tuning guide. Covered many times already.
Posted via Mobile
Posted via Mobile
Welcome aboard...Nice on the low miles.
Did it run decent when you first purchased it?
Did it run decent when you first purchased it?
Have you checked the diaphram for holes and to make sure it is seated in the grooves well.
@nj1639 do you remember johns post/thread about tying the top three coils of the slide spring?
@nj1639 do you remember johns post/thread about tying the top three coils of the slide spring?
Tech7
XS650 Junkie
Don't forget to check basics. Plugs, wires, compression, valve clearance, etc.
The diaphram has no holes and is seated correctly. I have bought a clymers off of ebay and am waiting for that. With that in mind does the main jet or jet needle control 3/4 throttle I kind of think I need to go bigger on the main or fit a washer under the needle does this sound correct or should I look else where?
To tell the truth, I don't want to run mine to 5k rpm. Mebbe 4500 max, don't have a need for any more than that with the gearing I'm using. More of a cruiser 'stead of a screemer.
When I first got mine it had 2into1 pipes and ran like crap. I'd be tempted to take yours back to a stock configuration with the exhaust and jets, get your rpm's where you want them and then do the mods. I know that mine was a great improvement with the stock pipes and jets, gave me a solid base to work from.
Good luck.
Good luck.
www/amckayltd.com/carbguide.pdf is the carb guide you want to read.
18 tooth front and 32 tooth rear. I was running 17/30 untill the last chain and sprocket change out. 17/30 is about the same as 18/32 but leaves a little more room around the front sprocket.
I'm doing around 65mph @ around 4k+ rpm. Damn site better than stock in my opinion.
My riding is highway, hills and hollers- no interstates in this neck of the woods. All my lower gears are very usable...not just something to go through to get to 5th gear.
I need to do a video ride sometime if I can figure out how to mount this camera.
Last edited:
bloodhound
XS650 Addict
main jet at 3/4 but the popping is that in the carb or the pipes?
bloodhound
XS650 Addict
yes, just don't get too far ahead it you have not set your valves and timing. Sync the carbs as well.
I've got stock jets and my XS, like most, will turn past the redline. It might be that you need bigger jets to cure a lean condition caused by open pipes but just changing to a bigger jet is not going to increase your RPM until you fix whatever is wrong.
Things it might be.
dirty carb
coil or coils breaking down
points if you have points
plug wires
spark plugs
shorts
stopped up fuel line or filter
timing?
more.....
But you can only check and/or adjust 1 thing at a time. Jetting is not the reason you're limited to 5000 RPM.
Questions:
Which side is popping?
Have you read and GAPPED the spark plugs? Spark plugs have not been factory gapped since the 1970s.
Which side is popping?
Have you read and GAPPED the spark plugs? Spark plugs have not been factory gapped since the 1970s.
