Unkle Crusty
XS400 Enthusiast
Story so far. Bought an 83 XS400 with a well worn 6 speed DOHC motor. So bought another motor, 5 speed and put it in. Installed new front and rear wheel bearings, Installed new swing arm bearings and shaft. Removed the forward third of the air box.
And painted the main parts an ugly purple, that Mrs Snippets likes. Brakes work, tyres are good. New bars, old ones were bent.
Starts okay, sometimes on one. At WOT will not rev past 6K, back off throttle revs to 8K. No filters on carbs at moment, 125 main jets. When trying to go past 6K at WOT, getting a spluttering type sound. Might possibly be pre ignition, but I do not think so. Today checked compression, 163 pounds on both cylinders, so no worries there. Will check timing next, could not find much info here. Will study the ignition system on the 6 speed tomorrow. My current thinking is the main air jets are the wrong size. Carbs came off the 6 speed motor. I have the jet sizes for the XS400J and the XS400RJ, but not sure which is which. Have the jetting for GTI Dave. Paper style air filters going on in about two weeks. Later will put on foam type filters. Then will get serious about studying jet sizes. Meantime some pointers on ignition timing would help.
Also, carbs are clean, checked the float level.
Just insured Deep Purple for another year. This will be the winter bike. However as mentioned in another post, I have an XS11 if DP fails to proceed.
Forgot. Checked the plugs, they look good.
Unkle Crusty*
And painted the main parts an ugly purple, that Mrs Snippets likes. Brakes work, tyres are good. New bars, old ones were bent.
Starts okay, sometimes on one. At WOT will not rev past 6K, back off throttle revs to 8K. No filters on carbs at moment, 125 main jets. When trying to go past 6K at WOT, getting a spluttering type sound. Might possibly be pre ignition, but I do not think so. Today checked compression, 163 pounds on both cylinders, so no worries there. Will check timing next, could not find much info here. Will study the ignition system on the 6 speed tomorrow. My current thinking is the main air jets are the wrong size. Carbs came off the 6 speed motor. I have the jet sizes for the XS400J and the XS400RJ, but not sure which is which. Have the jetting for GTI Dave. Paper style air filters going on in about two weeks. Later will put on foam type filters. Then will get serious about studying jet sizes. Meantime some pointers on ignition timing would help.
Also, carbs are clean, checked the float level.
Just insured Deep Purple for another year. This will be the winter bike. However as mentioned in another post, I have an XS11 if DP fails to proceed.
Forgot. Checked the plugs, they look good.
Unkle Crusty*