SPUDGUN

Oh yeah right side 125psi Left 130psi after compression test. Not sure how to work out what its meant to be... anyone know?

Bought a multimeter from Supacheap auto and it didn't work. Good one Stanley made in China. I think my petcock is gonna gonna be donated to landfill. still dribbles when ON. I set the valve clearances though. Have another look at it tomoz.

I read on another site the petcock is meant to be connected to the carb inlet right hand side brass nipple so I got all excited as mine just had a cut off bit of red hose on it when I bought it and the two carb inlet ports were capped off. But it didn't work once attched to petcock. Infact now petcock flows full when ON position so I'm in the market for a NOS one. Anyway bought a tried the fuel cap open as well btw no change. Blew thru the cap to see if intake on cap was blocked but air came thru. SO now I'm gonna check the valve clearances and timing position (static) armed with a couple of CC and colas. I'm not gonna take it to a mechanic, I won't I won't. Have manual and feeler gauge ready to be bent up also multimeter for the coil check

Hi I have same bike with similar probs of flooding carbs which I have cleaned many times and adjusted floats heights but you say it may be the needle valve if everything else is set up correctly. BTW the manual says 26mm float height measured with carb upside down from top of gasket to top of float. My plugs are black so you I figure there is too much fuel getting thru and thats why it dies after a few minutes running. I can keep it going with choke off and open throttle right up for a while but it won't idle if I let it off.

Carbs. Plugs. Filters clean. Floats set at 28mm as it was flooding and I checked the level with a clear house it was a couple mm above the fuel inlet height in the bowl which I transfered to the outside. Petcock replaced but still leaks out slowly when ON position. Pri and Res full flow. mmm Still doesn't run after 5 mins it conks out. I'm gonna check timing next after I try the floats at 26mm. I went to check points gap but it has a solid state ignition module instead so I'll just have to rely on that being right once I check the timing. Dumb question do I need to drain the oil first before removing the side cover or not. I saw a guy on youtube running the engine whilst strobe timimg so wouldn't the oil come out when running or seize the engine if empty???

I just bought a replacement petcock kit for 1980 xs 250 and when ON it still drips out a bit. It should stop completely right? changed all the o rings didn't break the diaphragm but it still leaks out...

I have the same solid state module in my 1980 xs250 and a bought a manual that only had info on the points type so this has been a great post. Thanks, BTW the manual description I bought included my model so Ive written to the seller for a refund.

I have had all the same issues and done everything you did bar the points. I also put in a replacement petcock kit but when ON it still allows a trickle through so not sure about that. STILL dies after 5 mins though so obviuosly haven't got to the bottom of it yet at least I have eliminated, float levels, dirty carbs, fouled plugs, plug leads, leaking petcock... so now clean air filter, check points, could it be valve clearance??? ignition coil??? sorry flying blind here. Any other suggestions. She's a nice looker at least

Cheers for that. I also just read in an XS400 forum that it could be flooding so I'm gonna try the o-ring replacement for sure. I'll repost if it works. "Viton" is meant to be the unleaded proof brand to get. I tried the screws out at 2 full turns last night to try and keeps the idle speed down to under 1500 but they were out more like 3-3.5 when I bought it and it still happened but I'll try again. Is premium fuel the way to go??? BTW I'll clean the carbs again before I bother reposting as well.

I have just bought same bike and same problem. Leave it for 10mins or so and it goes better for a few minutes then starts to die. Did you solve the problem yourself??? I thought it could be the fuel petcock needing replacing??? About to order a replacement kit as o ring is pershed and I have put a generic tap after the petcock. Any suggestions would help.