tamaman6 Posted July 30, 2007 Share Posted July 30, 2007 Ive just turned 16, i dont know alot about bikes. I picked up a yamaha DT 50 MX to ride until im 17. The owner before me reconned they did a complete rebuild of the bike. Its all running fine apart from when trying to start it up for the first time. It wont kickstart at all. The only thing i can do to get it running is by push starting it everytime I want to get it running. which is a pain in the ass when your out with your mates. any ideas on what might be the problem. I think its a 90' but i could be wrong. thanks in advance. Link to comment Share on other sites More sharing options...
tamaman6 Posted July 31, 2007 Author Share Posted July 31, 2007 Ive just turned 16, i dont know alot about bikes. I picked up a yamaha DT 50 MX to ride until im 17. The owner before me reconned they did a complete rebuild of the bike. Its all running fine apart from when trying to start it up for the first time. It wont kickstart at all. The only thing i can do to get it running is by push starting it everytime I want to get it running. which is a pain in the ass when your out with your mates. any ideas on what might be the problem. I think its a 90' but i could be wrong. thanks in advance. I really need help guys urgently. Another problem is security. I dont want it getting nicked, I dont have the steering lock key. Chains are known for being cut through can anyone give me some advice please?? Link to comment Share on other sites More sharing options...
fosdyke Posted August 6, 2007 Share Posted August 6, 2007 Hi Are you sure that the kick start is kicking over the engine? test for compression with the kickstart - you can do a simple 'rule of thumb' by taking out the plug, putting your thumb over it and cranking it on the kickstart - if it blows your thumb off compression is good and the kickstart is operating ok. As the bike runs when you you push it its reasonably ok - but 2 strokes are fussy, everything has to be about right or they just don't go: Check 1. Fuel is reaching the plug 2. you have a good (blue) spark 3. You have at least 120psi compression (@ full throttle) If you have all of these it should run - it may not run good, but it should run - after that check points gap, ignition timing, clean and reset the carbs, check the auto-lube (if it has one id working) - and put a couple of hundred miles on it. You may find after a while some of the niggly problems go away as crank seals soften. Good luck Link to comment Share on other sites More sharing options...
tamaman6 Posted August 7, 2007 Author Share Posted August 7, 2007 Hi Are you sure that the kick start is kicking over the engine? test for compression with the kickstart - you can do a simple 'rule of thumb' by taking out the plug, putting your thumb over it and cranking it on the kickstart - if it blows your thumb off compression is good and the kickstart is operating ok. As the bike runs when you you push it its reasonably ok - but 2 strokes are fussy, everything has to be about right or they just don't go: Check 1. Fuel is reaching the plug 2. you have a good (blue) spark 3. You have at least 120psi compression (@ full throttle) If you have all of these it should run - it may not run good, but it should run - after that check points gap, ignition timing, clean and reset the carbs, check the auto-lube (if it has one id working) - and put a couple of hundred miles on it. You may find after a while some of the niggly problems go away as crank seals soften. Good luck Thanks for your reply.. The weird thing is if i sit on my bike kicking it for about 3 minutes it will eventually start, and surely if it was what you were suggesting then it wouldnt start up if it was already warm. Link to comment Share on other sites More sharing options...
fosdyke Posted August 7, 2007 Share Posted August 7, 2007 OK so we know the kickstart works, and we know that it will go if you push it which suggests that you have 1. A spark 2. Some compression 3. Fuel reaching the plug You now need to check that everything is set up right - don't take anything for granted, the guy you bought it from may have rebuilt the engine - but he could have set it up wrong: Check: 1. Points gap and condition (if its not CDI) 2. Ignition timing 3. Remove and clean the carburettor - that means taking ALL the jets out and blowing them through with compressed air. 4. Compression - can't emphasize this too much - on a 2 stroke you need more that 100psi to get it to run real good 5. Auto-lube system is functioning 6. Reed valve (if fitted) isn't sticking Keep me posted - change the plug for a new one and use fresh petrol. Link to comment Share on other sites More sharing options...
tamaman6 Posted August 8, 2007 Author Share Posted August 8, 2007 Piston & barrel was completely screwed. Apparantly seized up. This aint gunna be cheap.. Link to comment Share on other sites More sharing options...
tamaman6 Posted August 8, 2007 Author Share Posted August 8, 2007 ordered a 60cc big bore kit.. I need to find 4 cylinderhead studs for a yamaha dt 50 mx. Any ideas where I can get one? I have searched everywhere!!! Link to comment Share on other sites More sharing options...
Lonewolf Posted August 12, 2007 Share Posted August 12, 2007 Hi.... I bought a yamaha dt50 mx 4 weeks ago and 2 weeks later i had an problem starting and driving it it suposed to be an ecnition problem .......i checked the bougie and the sparkplug both are ok even the sparkgaps are correctly adjusted and clean, what schould i do Sorry for my bad english but i come from holland and i m trying everything to solve this problem i i supose you guys know alot about this moped, even though my dad is a mechanic and thought me everything he knowed about engines and electronics. But we both cant find the real problem i can only discribe it like: when you are driving the yamaha and its good warm like 30 mins driving it starts to stop the engine the engine fails and you come to a stop sometimes you l have to push it for 2 meters and is ok again sometimes you cant do anything else than walk it home ,like everytimes it just starts the last 10 meters end just runs properly until you drive it good warm again and then the problem makes its way round and starts again......... Pleas help me Jen van de Venne Link to comment Share on other sites More sharing options...
tamaman6 Posted August 14, 2007 Author Share Posted August 14, 2007 new barrel/piston/gasket installed. now had much better responce. Feels like a totally new bike. Easy to kick over & starts first time. Love it... What would u guys suggest to wear it in... what should i do before going full speed...? Lonewolf. might be worth doing same as me check out www.wemoto.com Link to comment Share on other sites More sharing options...
lincoln10 Posted August 21, 2007 Share Posted August 21, 2007 I did 300 miles on mine before opening it up runs really nice. Has a 70cc polini kit 19mm dellorto carb boyesen power reeds Polini air filter Gets up to 56/57mph As for the starting problem. Did you use the choke? Mine can be a pain in the rear to kick start if i dont put the choke on. Lonewolf sounds to me as though the bikes overheating happened to me once. Check the heat rating on your plug & try a different one. I think mine is a 7 but not 100%. Link to comment Share on other sites More sharing options...
Lonewolf Posted August 22, 2007 Share Posted August 22, 2007 well now thanks for the reply but i thought i found it... i replaced the condenser (http://shop.wemoto.com/pictures.dyn?u=2147569qqq5828015) and ir ran perfectly but just for 2 days . now its broken AGAIN and i realy dont knw what to do i took it for say 12 km and it is broken again..... i cant tell what i m doing wrong ( i even didnt flatout it 75km/h) well at least the cops dont get me with my zundapp cuz it speeds only 50 and thats just alowed on the roads here... well i hope you guys can tell me ore else i dont know anything else than sending it to the moped shop 40 km from here so waiting for you're sugestions kind regards LoneWolf Link to comment Share on other sites More sharing options...
Lonewolf Posted August 26, 2007 Share Posted August 26, 2007 hi guys ... i would like some help here a few weaks ago i had an exident i ran into 2 bycicles and an expert is coming to see the damedge the yamaha has to run he says so i need to do the repairment this week pleas help me!!!! wel now i thinking of replacing the egnision coul next to the condenser i hope that works.... If i cant solve this problem ........then i m going to sell my orange yamaha monster cause i dont have money for all these repairs ... If i cant fix it and sell it i m going to buy ether a Gilera GSM ore an Rieju RR from the year 2000-2006 so if you can help me you can help me keeping one more yamaha on the road ,Another piece of wonderful history!! LoneWolf P.S. wanna see photo's of the yamaha now?? look here : http://www.brommerforum.nl/gallery/view/2824 if you see the photo's i d like your meaning HOT ore NOT and why..... Link to comment Share on other sites More sharing options...
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