_Wilson_™ 6,563 Posted September 5, 2020 plus ^^^ ... I'd re do it. if it was me ... you have all those fresh engine parts, as soon as the RTV starts breaking loose ... that engine is going to suffer... plus you've already invested your time, and money. 1 Share this post Link to post Share on other sites
Fishfiles 20,145 Posted September 5, 2020 When I look back at your older pics , I can see RTV silicone , that engine was gone into before and silicone used then , from the marks on the piston I would guess it was a lack of oil , screen is mostly already blocked up a large percentage from the previous failure 1 Share this post Link to post Share on other sites
_Wilson_™ 6,563 Posted September 5, 2020 (edited) i saw that... but looks more like it was sunk .... maybe a combination .. of both... anyways .. it's clean now, other then the RTV again... hm... we didnt pics of the screen (before it was cleaned) .. when it was broke down... that would have been handy.... for diagnosis... Edited September 5, 2020 by _Wilson_™ Share this post Link to post Share on other sites
texas123 87 Posted September 13, 2020 (edited) Well, I took it on it's madden voyage tonight & it's doing the same thing as before the rebuild, minus the smoke screen. Starts up after 2-3 kicks, idles & revs fine, goes thru all the gears well, but if the engine revs up past 1/4 speed, it stutters and doesn't rev up. Could this be a timing issue, fueling issue, spark? It really runs and starts up fine, but will not rev while in gear driving around. It will rev okay in neutral, but I didn't really push it too hard. I really hate to take it somewhere too. Edit: Pulling the choke kills it right away. Edited September 13, 2020 by texas123 Share this post Link to post Share on other sites
oh400ex 629 Posted September 13, 2020 (edited) I would pull the carb and go through it again. Sounds like something is blocked partially or not flowing correctly. Vacuum leak in boot? Have you done the spray starting fluid around the intake boot deal? (Or a similar test?) Spark is strong? Edit: Float level? Edited September 13, 2020 by oh400ex 1 Share this post Link to post Share on other sites
texas123 87 Posted September 13, 2020 18 minutes ago, oh400ex said: I would pull the carb and go through it again. Sounds like something is blocked partially or not flowing correctly. Vacuum leak in boot? Have you done the spray starting fluid around the intake boot deal? (Or a similar test?) Spark is strong? Edit: Float level? I'm not off work again until Thursday, So I'll try that then. I'm taking an atv trip Friday to Mena, Arkansas; anybody live near there want to ride that weekend? 1 Share this post Link to post Share on other sites
oh400ex 629 Posted September 13, 2020 (edited) 3 minutes ago, texas123 said: I'm not off work again until Thursday, So I'll try that then. I'm taking an atv trip Friday to Mena, Arkansas; anybody live near there want to ride that weekend? ~3 hours from me so a bit much lol Come up to NW Arkansas sometime! We have some awesome places to ride. Edited September 13, 2020 by oh400ex Share this post Link to post Share on other sites
_Wilson_™ 6,563 Posted September 13, 2020 22 minutes ago, texas123 said: Well, I took it on it's madden voyage tonight & it's doing the same thing as before the rebuild, minus the smoke screen. Starts up after 2-3 kicks, idles & revs fine, goes thru all the gears well, but if the engine revs up past 1/4 speed, it stutters and doesn't rev up. Could this be a timing issue, fueling issue, spark? It really runs and starts up fine, but will not rev while in gear driving around. It will rev okay in neutral, but I didn't really push it too hard. I really hate to take it somewhere too. Edit: Pulling the choke kills it right away. no, a spark issue wouldn't be the cause .... sounds like it's starving for fuel ... ... but you say it dies when then the choke is applied ... try choking it, and throttling it some ... and see if there's any change ... also look for dark exhaust gas out of the exhaust or a rich gas odor Share this post Link to post Share on other sites
SlammedRanger 1,556 Posted September 13, 2020 I had a very similar thing happen on a carb a buddy of mine pulled apart and cleaned. He didnt get the screws that hold the arm to the slide in tight enough. One fell out and the other was barely holding on. Under load it wouldnt take passed half throttle. But odd enough at idle it took any amount of throttle. I also had a cdi cause the same problem. That was actually vibration related i think. But it would rev fine at idle take it for a ride and it would cut out and pop and bang real bad. It was a ricks aftermarket deal switched back to oem and it ran 100% perfect. 2 Share this post Link to post Share on other sites
Fishfiles 20,145 Posted September 13, 2020 First thought carb issue , second thought timing ----what does the spark plug look like Share this post Link to post Share on other sites
RubiDan 596 Posted September 13, 2020 I bought a new 200X back in 1986 I think. I love the looks of them and both of my sons bring it up from time to time that they'd like to have one. I had a lot of fun with it and even rolled it over a big hill one time. Luckily I was able to get off of it pretty quick. It wasn't a powerhouse but it handled pretty decent and had pretty decent suspension. I hope you get yours running and have a good time with it. 2 Share this post Link to post Share on other sites
87Iroc 344 Posted September 13, 2020 (edited) This is an awesome looking ATC from my youth. I think I went and looked at one for 800 bucks back int eh day but it sold before I got there. Another option to cause that damage if you don't think its been sunk is maybe the carb went lean and they were running it hard and spark knocked it to death and it overheated the piston. Spark knock would be the flame front impacting another flame front and it would cause that 'sand' to form on top the piston and I can only imagine the head would look the same too. Edited September 13, 2020 by 87Iroc 1 Share this post Link to post Share on other sites
Fishfiles 20,145 Posted September 14, 2020 First thing I thought of was a diaphragm in the carb busted as it will do exactly the same thing your described , but looked at your carb breakdown and seen there isn't one on that carb ---then when I seen the plunger and it made me think of something elseI have run into , the plunger was installed 180 degrees out and there was a bevel on one side of the plunger , the bevel was facing the wrong way , you can't make that mistake on all carbs as there is a slot and a protrusion on the side of the plunger and it only fits one way , but some don't have a indexing groove , it almost looks like your has one in the parts break down ---- just throwing stuff at the wall , might get something to stick , LOL Share this post Link to post Share on other sites
texas123 87 Posted September 14, 2020 4 hours ago, Fishfiles said: First thing I thought of was a diaphragm in the carb busted as it will do exactly the same thing your described , but looked at your carb breakdown and seen there isn't one on that carb ---then when I seen the plunger and it made me think of something elseI have run into , the plunger was installed 180 degrees out and there was a bevel on one side of the plunger , the bevel was facing the wrong way , you can't make that mistake on all carbs as there is a slot and a protrusion on the side of the plunger and it only fits one way , but some don't have a indexing groove , it almost looks like your has one in the parts break down ---- just throwing stuff at the wall , might get something to stick , LOL I think the slide only goes in one way; but the bevel is towards the back not. Share this post Link to post Share on other sites
retro 4,048 Posted September 14, 2020 3 minutes ago, texas123 said: but the bevel is towards the back not. The cutaway on the slide has to face towards the air filter. If it is installed facing the head it is in backwards. 2 Share this post Link to post Share on other sites
texas123 87 Posted September 22, 2020 Just installed a Shindy carb rebuild kit; runs like new. The main jet was longer than the stock Keihin one and the needle set jet was stuck, so I couldn't replace it with a new one. It did not come with a needle jet holder either. I had a 108 & 110, and used the 108 jet per the manual. I'm at 115', so I was thinking to just use the larger one if I go into it again. The break in process will be cumbersome, especially since the hurricane is hitting us today. I'll post some pictures in a few days. Just got back from Mena, Arkansas for some atv riding; dang those guys are nuts. They know how to have fun though. Share this post Link to post Share on other sites
oh400ex 629 Posted September 22, 2020 Great to hear! Change your oil 😂 Share this post Link to post Share on other sites
texas123 87 Posted September 22, 2020 5 minutes ago, oh400ex said: Great to hear! Change your oil 😂 Oh yeah; probably 2-3x over the next 10-15 hours. I got almost 1 hour today, but with the tropical storm hitting us, it's been difficult to ride. I think the right front fork seal is blown, so that'll be next. The bike also sinks when I ride it (225#), so maybe stiffer shocks next. I'm actually picking up another project tomorrow, so the work will slow down a little. It's really a fun little bike though & I've always liked smaller engines since they're easier to rip around on. 1 Share this post Link to post Share on other sites
texas123 87 Posted October 4, 2020 I put about 25 hours on the bike since the rebuild & it's running flawlessly. Well, maybe a little flat spot early on the power curve and the shocks aren't set up for 225# people. The motor oil came out clean all 3 times also. I just smile the whole time I'm riding it and not because it can outperform my atvs or dirt bikes, but because it's soooo ridiculous to drive. Anyway, somebody offered me a lot of money for it, so I just sold it. It's really kind of dangerous anyway; I kept running over my legs & that solid rear axle was not very stable on bumps. I'll be looking for another project for the Houston winter, so any ideas would be cool. I appreciate everybody's help with this project & will keep in touch. 2 Share this post Link to post Share on other sites
oh400ex 629 Posted October 4, 2020 (edited) 21 minutes ago, texas123 said: Anyway, somebody offered me a lot of money for it, so I just sold it. It's really kind of dangerous anyway Perfect end to the story! This is the path most of my projects take as well 😅 You got to ride the nostalgia out of your system for now lol You did the right thing. ATC is great for the smile factor but they really are monsters. Happy for you! Edited October 4, 2020 by oh400ex Phrasing Share this post Link to post Share on other sites