Maybe I’m wrong and it’s not the valves. I have a a stethoscope and I listen to each valve cover and it doesn’t seem loud. But I’m getting backfiring through the intake side of the carb it’s idling up and down and I have this loud tapping. I did the valves again for the 4 time now I’m a pretty smart fellow when it come to motors but this one has got me stumped. Is there something else I should be checking any ideas will help
Raptor 350 valve problem
I have adjusted the valves 4 times cleaned the carburetor 3 times I’ve set the valves to the tighter side and looser side but I have a loud valve noise and it backfires through intake side. At higher rpms it doesn’t backfire but still really loud valve noise I’m ready to drive it off a cliff. Please help
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Maybe I’m wrong and it’s not the valves. I have a a stethoscope and I listen to each valve cover and it doesn’t seem loud. But I’m getting backfiring through the intake side of the carb it’s idling up and down and I have this loud tapping. I did the valves again for the 4 time now I’m a pretty smart fellow when it come to motors but this one has got me stumped. Is there something else I should be checking any ideas will help
Bent valve or air leak
So got it all back together and it started right up same noise. I decided to take some carb cleaner and spray it around the carb no change in running till I get to the brake side and spray it on the boot were it meets the motor and it starts reving really hi so that is telling me there is a leak in the gasket. I just ordered it will see if that fixes anythingBent valve or air leak
Nope not it put it on same shit noise and back fire. What do I do next guys!
So I figured out one issue I had and that was the valve noise I guess I’m not as smart as I thought I was. So I also have a 2004 Suzuki LTZ 400 that I did the valves on once I had to buy a special feeler gauge that had a .05 in a .08 measurement on it it’s one gauge but it has two sides to it I was looking at it and I was looking at the numbers and then I was looking at what I was measuring them out and when it said .06 to .10 I was actually going with a .006 to a .010 What a dumb ass huh. Now there’s no valve noise but I still have the hiccup in backfire through the intake in the idle Is a Radick even though I replaced that gasket between the intake and the cylinder when I spray flew over there it still changes the motor RPM. Any ideas thanks guys
Also the header pipe is glowing redSo I figured out one issue I had and that was the valve noise I guess I’m not as smart as I thought I was. So I also have a 2004 Suzuki LTZ 400 that I did the valves on once I had to buy a special feeler gauge that had a .05 in a .08 measurement on it it’s one gauge but it has two sides to it I was looking at it and I was looking at the numbers and then I was looking at what I was measuring them out and when it said .06 to .10 I was actually going with a .006 to a .010 What a dumb ass huh. Now there’s no valve noise but I still have the hiccup in backfire through the intake in the idle Is a Radick even though I replaced that gasket between the intake and the cylinder when I spray flew over there it still changes the motor RPM. Any ideas thanks guys
I will try a new boot and see if that fixes it thanks for ur input !
But that boot is thick as shit and I can’t see any cracks on it. Anyway I just ordered a new one and will pick it up when they open I will have it installed this afternoon. So hopefully that’s it !
Just picked up new boot and gasket will install when I get home. Update coming soon cross ur fingers
So I got home and before I put the boot on I wanted to check compression it’s at around 140 150 I also sprayed some carb cleaner in the intake valve hole and it bubbles could the valve not be closing all the way
I think I figured it out. I hooked up a compressor hose to the spark plug hole and pumped it up with air and put some liquid in the intake so the liquid is sitting on top of the valve and I got bubbles so that is telling me the intake valve is not sealing. Right
I did the new boot and gasket and the valve noise went away because like I said I’m a dumb ass and don’t no how to read feeler gauges but it still hiccups and pops through the intake. So I pressurized the cylinder with air and with the intake boot at the cylinder I can see the stem side of the valve I sprayed a bunch of carb cleaner in until it made a puddle all the way around and I get air bubbles. I did it at tech. So the rocker arm had play. I even checked the clearance again and was good.
So I already got the head off and on the workbench. Are the valves heads in the cylinder side supposed to be the same color. One of them is black the other is light grayish.
So with the head sitting on the work bench can and the cam sprocket pointed at tdc can I measure clearance
So. If I’m adjusting it to between 10 and 20 for exhaust and I use a .005 which is .127 mm that’s correct
No on my air box lid it says intake 0.06-0.10 exhaust 0.16-0.20
I found one issue with the intake valve side I filled up the intake with fluid and it’s seeping around the cylinder side so that is telling me the valve isn’t seated all the way right
I lapped both valves and got head back together ? Can I set the valve clearance before I put the head back on. Thanks
So I got it all back together I think it’s running good I took a video but don’t no how to post it
I’m uploading it now here is the link
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