Recent content by David Houston

Does anyone know xs400 mechanics in scotland

Hi there , I am looking for a Xs400 mechanic in scotland

hi there i am changing fuel system from vacumm petcock valve on tank to manual fuel tap , do i cap of the vacum ports on the inlet manifolds on ech intake maifold (mikuni bs34 carbs fitted} is that all i have to do for the bike to run normal , or do i have to do anything else. i would...

Spot on.

Hi guys I have a 1977 xs 400 . It starts and revs OK for about 5 mins then cuts out , it will not start again when hot . It will start again when engine is cold then cut out again in 5mins. All jets and needles are new. Any guys got an idea what is the problem. Ignition 100% spot on. New ht...

Hi guys I have a pair of mikuni bs34 carbs for my 1977 xs400. Could anyone tell me the diameter of the hole in Air Pilot Jet . I have attached a diagram. On the diagram the air pilot jet is number 53 on the air intake side of the carbs. The Air Pilot Jets were missing when i got the carbs...

Hi Guys Hopefully someone can help me out here.i have pair of Mikuni bs34 carbs on my 1979 yam xs400d. This issues are as following. I require 2 x pilot air jets with 6mm threads on pilot air jet , i have attached a pic of the air intake side of the carbs, they were missing when i got the...

hi there i have a 1979 xs400 , it has a non vacumm fuel tap on fuel tank and both vacumm pipes on carbs have been sealed. the compression is 145psi each cylinder.the timing is 100% spot on and replaced both HT coils so there is a great spark on each. i cant get the bike to start , the only way...

Cheers mate

Hi tyler I have checked it many times know, it is reading 70mm all over the cylinders . The piston ring gap when in the cylinders is over the max recommended. The pistons and cylinders are all in good condition. When i did a compression test i got 120psi on a dry test and 145psi on a wet test...

hi there hopefully someone can help me out , i have a 1979 xs400 it has been rebored and i require 1mm oversized piston rings. i cant seem to find them anywhere. does anyone now where i can get 2 sets. appreciate any help. cheers dave

cheers mate i will get my mates micrometer which is calibrated constantly due to work he does and will do a load more test all over the cylinders dave

I assume my micrometer is out of calibration and the engine has been rebored to 70mm , which is max on the xs400 i believe. The bores are in great condition no scratches or scores ( reading the same just under 70mm through out the chambers). Should i try fitting new 1mm o/s rings to pistons ...

i have trouble with low compression mine is 120psi should be about 165psi i tried a wet test with small amount of 2 stroke oil in each cylinder, refitted the spark plugs (did not fit the HT leads) the wet test brought the pressure up to 135 psi on each cylinder. stripped head off to make sure...

i have trouble with low compression mine is 120psi should be about 165psi i tried a wet test with small amount of 2 stroke oil in each cylinder, refitted the spark plugs (did not fit the HT leads) the wet test brought the pressure up to 135 psi on each cylinder. stripped head off to make sure...