Airhead

Nice intro

BR8 is a hotter plug than BR9 so may help Here's a useful picture

Yours looks nice, I can see why you recommend the guy. BUT you have to admit that your picture is many times better than his, thats just bad marketing on his part and were just having a laugh

When it is hot and cuts out, check for spark immediately, if no spark then maybe you need a new pulser coil as these are sometimes known to open circuit when hot. Then let it cool down and if the spark returns it is more confimation of this.

first ride today, only to the next town though, had a busy day so unable to go for a better ride. God it's gutless but was nice to ride even so

Welcome Isaac Bzzzzzzzzzchargethebatteryzzzzzzzz Apart from that I dunno mate.

Posted 11 September 2009 - 07:52 PM Another 1 poster guys

A bit lost now, you seem to have covered most of the bases, Starts fine when hot, but cuts out for an unknown reason That might be either fuel (stood for 6 years...hope you did a good job of cleaning the carb) or losing spark (sometimes pulse coils will open circuit as the temperature rises, should not make for difficult starting when cold) or a remote chance that you havent set the valve clearance correct so losing compression when hot. ( again should not make for difficult starting when cold unless its way out)

Be a while yet as the top end is down for a rebore, plus i need to re-paint that pipe. The trouble is that i have rode this bike so little recently...coupled with the fact it will be carrying other mods too, Reeds, carb, air filter.... so i wont be able to say just what this mod did in isolation When you say the 125 pipes are the same you mean your DT125R, they are heavily restricted with all the sound absorbing ant-gas flow matter that is stuffed in them, the clue is...start the bike allow it to idle for 15 minutes then place your hand on the pipe where it becomes fat...its still stone cold now theres some serious crap in those pipes Will do a thread on it when I attack mine.

Well it's out now Restrictor diameter = 29mm, Header diameter = 35mm This is now a 45% bigger area than when the restrictor was fitted.

sounds like possible fuel starvation to me, what kind of fuel tap is it, a standard gravity tap or a vacuum operated tap. If its a vacuum tap you need to set it to 'PRI' for a while when you have had the carb in bits. What is the fuel flow to the carb like?, pull off the pipe and run some through to check for a good flow, again use 'PRI' if it is a vac tap Are you using the choke when its cold? ...Paul

I was the same waiting for mine, the weather has conspired against me riding it evar since what with all the frost and salted roads, in the end i decided not to tax it as it was very late January, now its taxed and insured so hopefully i'll get out on it this weekend unless the weather spoils it again. Drewpy's the master when it comes to XS400 carb problems.

Dohh, them carbs are carp. Good luck with it.

I always go from second to neutral when i'm stopping and i also click for neutral just before i stop so dont have these 'problems'

How serious Drewps? can ye sort it?

Here is the starter arrangement, my tailpipe was made by SM (Serval Marketing) back in the annals of history, just dont see them anymore, not even on ebay. You need to sort out that cable routing though as this is likely the problem, you should hear the throttle (clunk) as it bottoms out when you shut it off

Sounds like you dont know your clutch from your throttle, if thats the case what were you doing stripping the carb down. Dont you mean then when i try and use the clutch throttle it will try to rev more power but just chudder if u get what i mean and then cut out.

What fender is on it now? I suppose any old fender would do for an off roader. Have the bike still got the bit of fender (black plastic0 that the swing arm passes through. this is the front part of the rear fender. then the seat base forms the top part. Finally the two piece rear part has a plastic top and a steel under section to take the weight of the rear light unit. As far as replacing the rear section its your call really so long as it is fastened securely and will hold a light / licence plate unit if required. Have you got a parts book? you can download one go the workshop 'sticky' As to the question though i dont know if it will fit youll have to try it and see. ...Paul

As far as the clutch goes, you could try warming the engine up until the transmission oil is warm, then kill the engine select a high gear 5 or 6 pull the clutch and rock the bike to and fro, this may work. Failing that you will need to strip the clutch plates out and seperate them by hand. When youve done change the transmission oil too.

Welcome in Steve Yep you have a problem with the float or float valve. To check the float just remove it and shake it to see if there's fuel in one of the floats (very unlikely mind) The valve has no doubt got a wear ring around the seat, you will see it better with a magnifying glass, (sometimes the spring loaded pin can be weak too) if it has buy a new one complete with seat, all that remains to be said is the float height setting to 21mm you will have to be clearer on the clutch issue, is it stalling when you put it into gear? if so might just be plates stuck together which is a common occurance through lack of use. ...Paul

be sure to wrap up warm now Joe

Yep...lets not waste any time on hello's here !

someone un-soldered the coils or what jan? ...Paul

Thanks Alex, hope its an easy fix for ya. Edit...all fixed now thanks

Not just you mate, i've sent Alex a message via email.