Green450s 1 Posted March 28 I have a 2000 Honda foreman 450s 4w4. When I start it up with the choke on its fine but when I take it off it will idle then make clunking noise like the piston is slapping the jug when goes up then it will act like it's going to die. Sometimes it will and when it does my battery doesn't have enough power to turn the 4wheeler back over. I just got a battery tender fix that problem. Can anyone tell me what is going on please. Share this post Link to post Share on other sites
shadetree 5,869 Posted March 28 3 hours ago, Green450s said: I have a 2000 Honda foreman 450s 4w4. When I start it up with the choke on its fine but when I take it off it will idle then make clunking noise like the piston is slapping the jug when goes up then it will act like it's going to die. Sometimes it will and when it does my battery doesn't have enough power to turn the 4wheeler back over. I just got a battery tender fix that problem. Can anyone tell me what is going on please. with it being 24 yrs old ?, its hard to narrow your issue down. the piston, or bore can be worn ?, the connecting rod can have play in it ?. wrist pin top at rod can be worn out ?, valves can be out of adjustment ?. really hard to tell you what it can be. the only way you will find out, is too tear the top end down, and inspect the piston, bore, valves, rings, connecting rod. BEFORE you tear it down !!. make sure to have a top end gasket kit, and a tube of yamabond or hondabond on hand !...DO NOT USE RTV SEALANT ANYWHERE ON THIS ENGINE !!!. i'll go out on a limb here, and say your piston, jug, connecting rod is worn out..one of these..or all 3 need to be fixed. 2 1 Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 28 Welcome aboard. Is it smoking? Have you tried upping the idle a bit with the knob on the bottom of the carb? And check and make sure your stator is charging with the machine running. Use a multimeter and make sure you are charging. If not, you might have a bad regulator. 1 Share this post Link to post Share on other sites
shadetree 5,869 Posted March 29 11 hours ago, jeepwm69 said: Welcome aboard. Is it smoking? Have you tried upping the idle a bit with the knob on the bottom of the carb? And check and make sure your stator is charging with the machine running. Use a multimeter and make sure you are charging. If not, you might have a bad regulator. i just have to ask !..what good is it if its smoking when making top end noise ?, why does it matter if its charging or not when it has top end noise ?..please wizard..tell me !..lol. Share this post Link to post Share on other sites
jeepwm69 7,611 Posted March 29 2 hours ago, shadetree said: i just have to ask !..what good is it if its smoking when making top end noise ?, why does it matter if its charging or not when it has top end noise ?..please wizard..tell me !..lol. Noise could be something as simple as valves needing adjustment. Idle might be low or have a dirty carb rather than need engine work. More than likely you’re right, but might be a simpler fix. Share this post Link to post Share on other sites
Green450s 1 Posted March 29 On 3/28/2024 at 5:36 AM, shadetree said: with it being 24 yrs old ?, its hard to narrow your issue down. the piston, or bore can be worn ?, the connecting rod can have play in it ?. wrist pin top at rod can be worn out ?, valves can be out of adjustment ?. really hard to tell you what it can be. the only way you will find out, is too tear the top end down, and inspect the piston, bore, valves, rings, connecting rod. BEFORE you tear it down !!. make sure to have a top end gasket kit, and a tube of yamabond or hondabond on hand !...DO NOT USE RTV SEALANT ANYWHERE ON THIS ENGINE !!!. i'll go out on a limb here, and say your piston, jug, connecting rod is worn out..one of these..or all 3 need to be fixed. I was thinking it might be idling a little low so i will turn the throttle up some. I bought some fuel system cleaner is that worth putting in? I took the carburetor off and looked at it and it seemed clean to me no sludge or anything sticking. When I got it the man said that he had the carb cleaned and everything maybe he didn't fine tune it. I went to a 4wheeler mechanic and he said that the carb sounded like it needed to be looked at because there was a little hesitation in the throttle. I will look up were the stator is and check the voltage to see if that is correct. No it doesn't smoke at all never has. Thanks for your advice i Iike having someone with knowledge around that can help me learn. Share this post Link to post Share on other sites
AKATV 822 Posted March 29 I was kind of thinking the same- might just be a carb thing, as he said it runs fine with choke on and THEN clunks when you take it off choke Could just be struggling to run at low rpm and not clunking/slapping- but "described" sounds are different for everyone, so its hard to tell Might try turning idle up like Jeep said,, check or clean enrichment valve(choke) and make sure rubber boot under top cover of carb is not pinched if it has a throttle response hesitation. -Maybe post a video of it to better interpret sounds/issues -AKATV Share this post Link to post Share on other sites
Green450s 1 Posted April 1 Well I turned the idle up. It helped alot. I also changed the button on the side of the carb that you push to get more fuel because it was leaking. I also believe my battery is dead. I was curious to see how old it was and it's 3yrs old so I'm replacing it also. Does having a weak battery cause the types of problems I'm having? Thanks for telling me to turn the idle up to check the choke cable I did and it looked OK. So at the moment it's running as it should. Thanks again for helping me out. I bought a service manual and it is arriving today and I can't wait to read it. Share this post Link to post Share on other sites
AKATV 822 Posted April 1 Glad to hear that you got it running better Sounds like most of your problems were just fuel / carburetor related A weak battery wont really cause the issues that you were having with running, but the ES systems definitely need to have a good battery in place for proper operation as far as electronics and shifting, etc. Glad to hear you have a service manual coming, just so you know, we have a pretty much full digital library where are you could have downloaded it for free. You can see the link at the top of the homepage. If you need any more help or have any other questions, just let us know -AKATV 1 Share this post Link to post Share on other sites
Green450s 1 Posted April 8 Hey this Green 450s. I cannot find the service manual on the home page for my 4wheeler yr and make. Can you please point me in the right direction? Share this post Link to post Share on other sites
AKATV 822 Posted April 8 (edited) Are you viewing the forum on your cell phone or on a computer? If you’re on a phone, click the three white bars in the upper right corner and you’ll see the link for service manuals it will look like the very bottom picture If you’re on a computer, see the picture right below -AKATV Edited April 8 by AKATV 1 Share this post Link to post Share on other sites
Green450s 1 Posted April 9 Quote I found it and got it downloaded. Thanks again AKATV. 1 Share this post Link to post Share on other sites
