My engine on my 2000 kdx200 is making a banging noise. I does not get louder when it revs. It actualy kinda goes away. I changed the gear oil and put 700cc in it. It still made that noise. I just bought it last week ago. It's in real good shape. just a few scratches. I took the spark plug out and it was a little brown right at the tip. I guess thats good. I have the stock pipe & silencers on it and the air box lid off. Please help me out here.
Banging noise from engine?
- Thread starter Aaronkdx
- Start date
"Banging" is a little vague. KDXs make lots of crankcase noise. You might try dumping the rest of the quart of oil into the crankcase and see if that reduces the noise. Many of us do this with good results. If that doesn't help try giving a little more in depth description of the noise.
- Thread starter
- #4
I can't really desribe it, it's almost as loud as the engine & exhaust(stock pipe&silencer) but it goes away when you rev it alittle. I am taking to my local shop to have them look at it tommorow? Does any one else have this problem. This kid that lives out the road and has a rm85L say his dad's 04 rm250 does the same thing. His dad says it's PISTON SLAP. He also said that those 200 Kawasaki do that.
css_elfers
Member
- Aug 26, 2004
- 166
- 0
My brothers 98 200 does the same thing. We've done all that you have said you've done with no improvement. Let us know what the result from the shop is.
Thxs
Elf
Thxs
Elf
Although the normal KDX crankcase noise is pretty loud it's not piston slap. If you've heard piston slap you'd know if that's what it's doing. Piston slap is what you get when your piston is worn out and the clearance between the piston and cylinder wall is too great. It's cure is to replace the piston. I have a KDX200H with an FMF-30 pipe, An FRP pipe guard, and an FMF Q silencer. My crankcase noise at idle is greater than the exhaust noise even with a full quart of 10-40 or 20-50w oil in the engine (the manual calls for 10-40).
- Aug 29, 2004
- 2,958
- 0
cr deathrattle sound familiar ........the honda clearances are way off i put a B piston in my A cylinder and whallaa :cool: death rattle mystery solved :bang: too bad i didnt join before the dozens of speculating threads i poured over looking before i got a chance for a top end
- Thread starter
- #9
OK so I got the top end off the bike and am taking the sylinder to a shop. The guy listened to the bike and said that it is louder than it should be, so got home and started taking stuff apart. The bearing that the connecting rod goes to in the bottom end has alittle bit of play :bang: It has side to side but thats normal. Up and down is bad :| So I will post later when I find out more
- Aug 29, 2004
- 2,958
- 0
give it a go yourself first , worst could happen is you pay to assemble only instead of all
heck i saw a thread a couple months ago a guy offered beers and dinnner to any DRN'er in his area who'd oversee his project and the guy got multiple responses and some more riding partners :)
heck i saw a thread a couple months ago a guy offered beers and dinnner to any DRN'er in his area who'd oversee his project and the guy got multiple responses and some more riding partners :)
- Thread starter
- #12
Well I took the bike to the shop and let them look at the conecting rod with the play, and they said that its fine. It just must have been my inagination. Well the pistion was a little worn, so I just ordered a new top end. He said he coundn't find what was wrong with it. So I will see if it makes that noise after the new top end and breaking it in. The cylinder is good.
razrbakcrzy
Member
- Aug 12, 2004
- 136
- 0
you have the KDX rattle. I venture to say that it is the same as all other kdx's. They all rattle during idle. It's a fact. What happens is you get use to hearing a bike that does not do this and it makes the KDX's sound like they are going to blow up. Just calm down and ride.
Jim
Jim
Glad I found this forum. I recently bought a nice 1986 KDX200 for $700 USD. Only thing missing was the stock muffler insert (baffle pipe). But when the seller fired it up and I heard that engine noise, I figured I'd have to do a top end job. Seller said "It always makes that sound"--guess he was right.
So after checking it all over after I got it home, I greased the fittings, oiled the chain, changed the trans. oil, and went for a ride. Runs fine below about 1/3 throttle, but simply will not fire above that. It just goes way lean, not rich. Returned home thinking the main jet had to be plugged. Pulled the float bowl and the jet was clean-as was the rest of the carb. The float level wasn't low at all. I looked at the jet under a low-power microscope and it appears to be a 320--the carb. is a Mikuni, not a Keihin.
Any ideas on why it goes too lean to fire? As soon as I return the throttle below ~1/3 it runs fine!l
So after checking it all over after I got it home, I greased the fittings, oiled the chain, changed the trans. oil, and went for a ride. Runs fine below about 1/3 throttle, but simply will not fire above that. It just goes way lean, not rich. Returned home thinking the main jet had to be plugged. Pulled the float bowl and the jet was clean-as was the rest of the carb. The float level wasn't low at all. I looked at the jet under a low-power microscope and it appears to be a 320--the carb. is a Mikuni, not a Keihin.
Any ideas on why it goes too lean to fire? As soon as I return the throttle below ~1/3 it runs fine!l
Benesesso, If it's lean it will cut out on you. If it's rich it'll "4-stroke" on you (acts like it resists gaining RPMs, just kind of "misses"). If it is indeed lean I'd check for a fuel starving problem (tank petcock or pickup tube, dirty needle and seat assembly, low float level). You can test your lean theory by adding some choke when you're in the problem area and see if the situation gets better or worse.
Rhodester,
Thanks for the quick reply. The problem isn't "fuel starvation" in the usual sense-the engine just quits firing instantly any time the throttle is opened more than ~1/3. It doesn't load up (rich)-it immediately runs fine as soon as I back off the throttle. It also happens at any RPM-low, mid and high.
I'm starting to think the KIPS is to blame--gotta read up on how it works.
Thanks for the quick reply. The problem isn't "fuel starvation" in the usual sense-the engine just quits firing instantly any time the throttle is opened more than ~1/3. It doesn't load up (rich)-it immediately runs fine as soon as I back off the throttle. It also happens at any RPM-low, mid and high.
I'm starting to think the KIPS is to blame--gotta read up on how it works.
Rhodester,
OK, I'll try the choke tomorrow. I also regapped the plug down to .018" from .025". I'm now thinking that the ignition may be dying and simply can't fire a .025" gap under high cyl. pressure. This makes sense to me because the failure to fire is just as if I were flipping a switch--it's so abrupt both failing to fire and then running fine as the throttle is backed off--no blubberling, etc. at all.
OK, I'll try the choke tomorrow. I also regapped the plug down to .018" from .025". I'm now thinking that the ignition may be dying and simply can't fire a .025" gap under high cyl. pressure. This makes sense to me because the failure to fire is just as if I were flipping a switch--it's so abrupt both failing to fire and then running fine as the throttle is backed off--no blubberling, etc. at all.
Thread resurection time. My engine cut-out problem was the spark plug gap. Regapping it to .018" solved the problem.
New problem--where does the rubber tube (breather tube-?) go that's located on the engine just below the carb? Is it just a drain hose? I pulled the carb off a while ago and can't remember where it goes.
Bike is an air-cooled 1986 KDX200.
New problem--where does the rubber tube (breather tube-?) go that's located on the engine just below the carb? Is it just a drain hose? I pulled the carb off a while ago and can't remember where it goes.
Bike is an air-cooled 1986 KDX200.
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