Bossdaddy 207 Posted May 2, 2022 It's not mine but I thought I would try and help a friend of the family. When he brought it to me it would run but only with the choke half on, it would run pretty good, plenty of power, he just wanted it fixed. The owner had put a Chinese carb on it about a year ago and shortly after installation he had to engage the choke to keep it running. He brought the original carb when brought the machine. I ordered a rebuild kit for it and cleaned the carb while I was waiting for the kit. I rebuilt the carb and got it installed this afternoon. It fired right up, I idled it up just a little and let it warm up good then adjusted the, I believe ya'll call it the pilot screw not sure but the only adjustment screw there is, very little since I set it two turns off the seat prior to installation. When I went for a test ride it ran perfect, no hick-ups at all but when you go to accelerate it don't bog down it just don't have the power it should have, almost like it is starving for gas but not running rough. It's hard to explain, I've never experienced anything like this before, maybe I did something wrong. I know with all the experience on here somebody has probably seen this before. Sorry for being so long winded, HELP!! 1 Share this post Link to post Share on other sites
Goober 1,547 Posted May 3, 2022 Check the jets are spec, the main needle clip is set on the third station and there are no holes in the piston valve rubber. Make sure the rubber is aligned properly Share this post Link to post Share on other sites
shadetree 5,429 Posted May 3, 2022 did you use a shindy carb rebuild kit ?, or did you cheap out..and buy a no-name kit from ebay/amazon ?. did you flush the tank ?, did you check the fuel flow ?, did you see if the oem snorkel was clear ?. did you check the intake boot for tears ?. is the air filter clean ?. is the valves adjusted correctly ?. spark plug fresh ?. check the timing ?, diaphram torn or holes in it ?. as you can see..there is more to a carb than just putting parts on an atv engine !. last but not least..if the c.d.i. is worn out, going bad ?, it wont rev right. Share this post Link to post Share on other sites
Goober 1,547 Posted May 3, 2022 Check to make the tank is clean and …see the nut on the bottom of this petcock? There’s a screen in there! Share this post Link to post Share on other sites
toodeep 1,712 Posted May 3, 2022 Some 300s are doggy compared to others while yet others are hot out of the box. Just something to keep in mind when chasing an iffy problem. If the rubber on the throttle plunger is expanded, not properly seated or has a hole in it you won't get full throttle out of it or quick acceleration. Share this post Link to post Share on other sites
Fishfiles 17,030 Posted May 3, 2022 I'd go for the easiest things to check first , compression test the engine (had a beat valve stem beat me up one time trying to troubleshoot it ) , pull the timing chain adjuster out and see if the chain is stretched out , and check that diaphragm in the carb for a hole or crack Share this post Link to post Share on other sites
Bossdaddy 207 Posted May 3, 2022 Guys thanks for all the input I'll start trying to work thru the list. I'll report the results. 1 Share this post Link to post Share on other sites
Wheeler 2,275 Posted May 4, 2022 I’m a little te to the game, but they covered all the key points! Share this post Link to post Share on other sites
Bossdaddy 207 Posted May 13, 2022 Went back thru the carb again and flushed the tank. Added fresh gas and she took off like it should. When going back thru the carb I did notice some blockage in the main jet so that prompted me to flush the tank. I used a Moose Carb Kit. 1 Share this post Link to post Share on other sites
Goober 1,547 Posted May 13, 2022 Sometimes that primer plunger seal breaks up and flushes more chunks in the bowl Share this post Link to post Share on other sites
shadetree 5,429 Posted May 13, 2022 2 hours ago, Bossdaddy said: Went back thru the carb again and flushed the tank. Added fresh gas and she took off like it should. When going back thru the carb I did notice some blockage in the main jet so that prompted me to flush the tank. I used a Moose Carb Kit. you should have used a shindy carb kit, its just as good...if not better than oem from honda. Share this post Link to post Share on other sites
toodeep 1,712 Posted May 14, 2022 5 hours ago, shadetree said: you should have used a shindy carb kit, its just as good...if not better than oem from honda. Moose use to be just rebranded shindy. I'm not sure who they have for a supplier now days though. Share this post Link to post Share on other sites
shadetree 5,429 Posted May 14, 2022 7 hours ago, toodeep said: Moose use to be just rebranded shindy. I'm not sure who they have for a supplier now days though. moose is made in Taiwan or china now ?, shindy is made in japan. ( unless you fall for a knock off ? ). Share this post Link to post Share on other sites
Goober 1,547 Posted May 14, 2022 (edited) I have also had good luck with K&L. They have different sized kits offering screws and passage plugs. I bought a couple off fleabay for $2. Labeled Made in Japan Edited May 14, 2022 by Goober Share this post Link to post Share on other sites
toodeep 1,712 Posted May 16, 2022 On 5/14/2022 at 6:35 AM, shadetree said: moose is made in Taiwan or china now ?, shindy is made in japan. ( unless you fall for a knock off ? ). All moose does is rebrand parts from other suppliers. In the past I have installed both kits and they was exactly the same kits, exactly. Like I said, I have no idea who they are using for a supplier now but to make more money I'm also guessing from china. Share this post Link to post Share on other sites
Bossdaddy 207 Posted May 17, 2022 Thanks for the info. Share this post Link to post Share on other sites