RD250 E very difficult to start

[ogri211]

A friend of mine has bought an Rd250 E, which looks to be in very nice condition, but he can never get it to start. I have went over to his house a couple of times and got it going for him and when it is running it rides perfectly and ticks over. I have taken the carbs apart they are clean, I have checked the float heights, and checked for air leaks ( none,this would stop it from idling as would faulty reeds.) We have tried several different plugs, balanced the carbs, set the oil pump , what happens is I need to kick it about 20 times to even get a splutter and it needs full throttle, will start to catch slowly eventually on one pot then will slowly get away. once the bike heats up it idles and runs fine. I have checked the heads are tight there doesnt seem to be any wear as it runs nice and quiet when it eventually does go. His wife has the exact same bike and hers starts 1st or second kick every time. She has gave me permission to try her carbs on his bike ,so I was going to try and swap the carbs on both bike to see if the problem was with the carbs or not, the only thing I was thinking was a problem with the choke circuit. I would be grateful for any suggestions if anyone has had the same problemand found a cure, as I say when the bike is going it goes great so that eliminates crank seals or a lot of problems.

[reedpete]

Float bowls are specific for choke and right side but either fit either side....possibly they are on the wrong way round....well known head scratcher that one!

[ogri211]

Thanks I will check that out because the bike has the symptoms of a choke problem very difficult to get going but once it's running it goes fine , how is it you tell the difference with the float Boal's anyway?

[reedpete]

One has a drilling into the fuel ‘pot’ , the place the brass tube on the choke side goes down into.

[gazzatt2]

the pipes from the float bowls up to the air filter should be on the inside when he carbs are fitted on the bike

[urbantangleweed]

99.9% it will be float bowls on wrong carbs. I had exactly the same thing on a YPVS, complete pig to start but once running it was fine, checked everything and it made no difference, saw about the float bowls on another thread here and sure enough they were on the wrong carbs, switched them over and it started straight up and has done ever since.

[mikelc]

I had exactly the same problem as you ogri if you take the choke plunger out there is a small hole at the bottom which lets the fuel through mine was blocked up cleared it out and now starts 1st kick

[Ozhammer]

Probably less likely but slight blockage of the pilot jets can also give a similar problem and that was after I had paid an ‘expert’ to refurbish them. It was a bugger to figure out at the time but fortunately it led me to discover that the two stroke oil injector ports were also plugged, so in hindsight, it’s probably just as well it wouldn’t start easily as it would have seized running like that once the initial tank of pre-mix had been used.

[ogri211]

I had a look at it, and the float bowls were correct, I cleared the wee hole out and made sure the fuel was going into the chamber, still no good, I swapped the left hand carb with the one off his wifes bike which alaways starts first kick, and it still wouldnt start, but the slides were open quite a bit due to the cable being tight, I reset the cables balanced the carbs and set the oil pump, but still no good. As usual I managed to get the bike going with about 30 kicks with the throttle full open and it spluttered into life, we took the bike out a run and again it went perfect. I asked him to try it the next day when it was cold and sure enough it wouldnt start, my next thing is to put both his carbs in my ultra sonic bath to check that everything is clear, beacuse it still sounds like a starting circut problem to me.

[hoist1]

Think you need to fit both his wife’s carbs to be sure, even then it’s not conclusive. Even though it may seem smooth and quiet and tick over, i would be taking the top end off while carbs are off, the clue ( to me ) is he has only just bought it.