RD250DX 1977 carbs

[jeffw]

Hi all

im new on here and this is my first post, I had an RD250dx back in the early 80's and always regretted selling it, but now I've rekindled my bike enthusiasm and bought an RD250DX 1977 coffin tank and ally wheels.
i have a leaky carburettor, looks as if a pipe is leaking petrol when started, is it an overflow pipe?, the bike is a German import, red in colour, the question I have is what could cause the leak and/or is it advisable to completely strip and give the carbs new jets mixture screws etc or is there a simple know common fault after the bike hasn't been used much, sticky float pin valve or anything else.
the bike is in great condition for a 40'year old bike and it will be even better when I've finished with it, 

[sispeed]

Hello,
which pipe is leaking? There are 3 on each carb. I think it's the one from the float bowl.
Try hitting the bowl slightly with the backside of a screw driver and see if it stops.
If not you have to open the float bowl and check if the valve hangs or is not sealing.
May be it is the bike I sold to a UK importer a while back. What did you pay for it.
Regards Siggi

[jeffw]

Hi siggi
Thanks for your reply, I've bought a carb kit to overhaul both carbs, I don't know the history of the bike, for my own peace of mind I thought best to do the lot.
Was thinking of getting the Newtronics electronic ignition set, any thoughts on that?
I got the bike from eBay from North Wales for 2k, condition is good generally, it's had new parts chain & sprockets, fork seals head set bearings, front disc and pads and a few other bits as well, guy even threw in a dial measure for ignition timing, is it 2mm before TDC for timing?
Regards
Jeff

[sispeed]

Hi Jeff,
2mm is correct. If it has new TKRJ Pistons it could be the bike.
Left exhaust has marks from battery acid
Newtronics is ok. Not superb, but not bad from my experience.
Sold it for 1250,- euro
Regards Siggi

[sispeed]

Here are some pictures from my bike
schrauberbude.de/motorrad/yamaha_rd250_red77-2.html
Regards Siggi

[dusty350]

Hi Jeff
Welcome to the forum
If the bike has stood a long time with fuel in the carbs it will be worth pulling them and giving them an overhaul, including an ultrasonic clean which is the only way to really clean all the little passageways inside the carbs. Muttsnuts on this forum offers an overhaul service for a very good price. Might be easier for you in the long run unless you have the kit to do it yourself. Certainly sounds like a sticky float valve though.

Enjoy your new bike, and the forum

Dusty

[jeffw]

Thanks for the replies, I have bought card overhaul kits from yambits going to have a go at it myself, it's been a long time since last owning an rd, 35 years, man that makes me feel old haha, my original bike I bought was damaged and by coincidence I spray red, the one I have now is red, the last time I saw my old bike someone had put a 400 engine in it DPU108T, funny how certain reg number stick in ones head

Jeff

[Ozhammer]

Word of caution about the Yambits carb kits Jeff, they will almost certainly be Keyster or another pattern brand, which are not as good as the genuine Mikuni parts, so most on here won't use them.

Mikuni stuff is available but is obviously more expensive, so you pay your money and you take your choice I guess but carbs are one of a number of areas that it is important. to get as right as possible on these bikes if you want the best from them.

Also, make sure you read the threads on removing the brass balls and cleaning the air corrector passageways, as this is essential stuff.

Hope this helps more than it confuses!

Rgds
Ozhammer

[jeffw]

Thanks ozhammer, sounds as if you certainly know what you're talking about, I wasn't aware of the mikuni parts, if I'm going to do the job I may as well do it properly, where are the mikuni parts sold, in the uk?
To save me loads of reading could you give me a link to the forum page about air corrector passageways, I would very much appreciate it.
Thanks again fo the info, I've forgotten most of what I learned about these bikes.regards

Jeff

[Ozhammer]

No dramas Jeff, that is what places like this forum are great for, lots of like-minded enthusiasts looking out for each other.

Norbo Lea (the guy who runs this forum) has an online shop that stocks some Mikuni parts at reasonable prices and another often mentioned source is Allens Performance, so you should be able to get a lot of what you need from one or the other.

Rgds
Mark

[jeffw]

Does anybody know how I can contact Muttsnuts about carb refurb? I sent him a message on Friday but no reply as yet

Jeff

[Ozhammer]

He might be on holiday Jeff but just check your outbox to be sure that your PM actually got sent to him. He is usually very quick to respond to any enquiries.

Rgds
Ozhammer

[jeffw]

Siggi

On your bike are the wheels painted or left in casting colour, mine are painted with a very light colour, do you know if that is standard?

Cheers

Jeff

[paulsx]

If its a DX the wheels should be painted, the early c and d ones were as cast.

For the carbs as said reuse the original bits as much as possible, as said the keyster suff can be hit and miss the only bits thats werent any good from mine were the pilot jets which are a b*****d to get out generally and the float valves.

If your has been standing its most likely the float valves that are stuck or sticking and either need cleaning or replacing. Make sure all the jets are either the originals or mikuni replacements the pattern ones aren't great.

Pretty sure I brought pilot jets, float bowl gaskets and float valves from Norbo quite cheaply, I ultrasonically cleaned the carbs myself and cleaned all the brass parts separately.

[sispeed]

Jeff,
sorry for not responding for a long time.
Was racing and on holiday.
Can't remember exactly, but I think it was not painted.
Regards Siggi