sschering

These guys are down in Oregon.. http://www.nwvintagecycleparts.com/index.php

Sound like you might have a clogged pilot circuit.. It's often mistaken for a vac leak.. Have you tried cleaning the carbs? Pilot jets are under the brass screw in caps next to the main jets. That passage leads to the pilot screws and then to 3 tiny holes on the roof of the throttle bore on either side of the throttle blade. clean em all out really well. Sometimes the pilot jets are stuck and you have to easy-out em and replace.

What RPM do you like to turn at highway speeds? say 60mph or 100kph I've been running about 4,500rpm in 6th but it feels a little bogged down. I ran for a little today at 7,000 in 4th. It Sounded great and ran really nice. I don't want to abuse it but it just like it was more at home in the higher RPM's. My bike is a 77 XS-400D http://www.pontiacs.org/modules/gallery/album11/IMAGE_008

I have a spare set at home for an 80 XS-400.. same as the 77 XS-400 part.. I'll measure when I get home.

I plan on doing more work over the winter.. I'd like to strip it down, power coat the frame, trees, chain guard and swing arm. Also clean up the wheels. It'll also need new mufflers soon. I can't decided what to do about paint.. the original paint is a bit dull and the emblems are not so hot.. BUT it is original paint..

No need for a new wife.. Hey she's getting me a new helmet for my birthday. She's the one who found the bike and was OK with me getting it. Plus in my state if you are caught riding without a motorcycle endorsement your bike gets impounded.

I got the XS400 out, washed it up and went for a spin around the lawn.. My wife won't let me past the driveway till I get my endorsement. It's running great.. needs a new seat cover though.

I have the same bike and just finished going through the carbs.. Almost all the parts are avaliable from Mikes XS http://www.mikesxs.net/ We have a earlier model of the BS34 carb used on the 80-up XS650 I'd recomend checking to be sure the diaphragms are not torn. to do this look in the intake side of the carb... push up the needle slider and then cover the oval hole on the top of the intake with your finger.. let go of the slide.. if it holds they are good. Also be sure they slide smoothly and don't hang. If you do take the sliders/diaphrams out be careful with them.. a new set is about $120 a pair. while you have the bowls off to check the float level you might take the time to pull and clean the pilot jets. these are located under the brass plugs right next to the main jets. also clean out the passages for the pilot jets and needle screws while you are at it.. If you open the throttle and look inside from the motor side you'll see 4 small holes in the roof.. the closer one is the passage for the needle screws, these are also called the pilot screws the 3 others are for the pilot jet circuit. You might see posts about the pilot jets being under rubber plugs but that's for the 80-up carbs.. Ours are srew on under brass caps. They also talk about removing a pressed in cap to access the pilot screws.. the 77 carbs didn't hide the pilot screws so don't go pulling out any plugs looking for em. the 80-up BS34 rebuild kits don't work for our carbs.. they changed the needle/seat design.

I was worried someone would say that.. that bracket is broken off and missing.

Anyone know where the rectifier mounts on a 77 XS400?

Does anyone know if the 1978 XS650 Rear MC rebuild kit will work on a 77 XS400D? Yamaha part for the 77 XS400D is 1U4-W0042-50-00 78 XS650E is 1J3-W0042-50-00 Close but not quite an exact match.. The pics on the kit from Mikes XS look correct.. If I knew the bore size of the XS650 part it might help. Or maybe someone can help me figure out what is wrong with the one I have.. It holds fluid and isn't leaking.. It will pump fluid but will not pull in fresh fluid from the resouivor. I've stripped it down and cleaned all the passages.. when it's dissambled fluid will drain from the resivour into the cylinder bore. The bore looks good.. No pitting.. cleaned passage from Resivour to cylinder bore. I've cleaned the little passages in the piston but the little spring valves don't make a good seal. I'm assembling as follows. Sping.. large end first, small capped end facing out Rubber cup lip first.. flat end facing out. piston, valve end facing rubber cup retainer washer lock ring.

I found one through Grainger http://www.grainger.com/Grainger/items/1EXZ7 12v 11A with the correct dimensions. but kinda spendy at $100

the 1980 code is 3F9 I picked up a no title 77 XS400 today.. Just needs a battery, seat cover and some minor fixes. Vin 2N2

Is there a Sealed Led Acid battery that will fit this bike or is the standard vented LA the only option? All the sealed ones I've found so far are to wide or low amps

It's a 1980 XS400 Not sure if it's a special or not.. Can you tell from the VIN? It has the XS650 Special type seat latches so the seat flips up from the back.. not to the side. (If I had a seat to flip)

I think you are right.. I've been collecting pictures of tanks and seats to compare.. The XS400 seat is open on the tank end with 2 brackets to hook onto rubber grommets bolted to the frame. It shares the rear latch system with the XS650 Special seat. When mounted the front of the seat overlaps the tank slightly. Both bikes also use the same grab bar. THe XS650 seat is a closed end and butts up aginst the tank. It has a single brackets that hooks around the bushing for the rear tank mount. (I think it does anyway) The tanks also differ slightly.. the XS400 appears to drop down over the frame more than the XS650 tank but appear to use the same basic mounts. Is the XS650 physicaly longer than the XS400? I'm just wondering if the XS650 Special seat and tank would fit a XS400 if used together. It looks lithe the XS650 seat/tank might be slightly longer overall. I'm think the XS650 tank will bolt on but I don't think the stock XS400 seat would fit with it.. I guess I better look harder for XS400 parts.

Just a quick question.. Will the tanks from the bigger bikes bolt up to a XS400 frame? I just picked up a XS400 but I'm missing the seat, tank and side covers. It would really help to know what models I can pick from.. I found a 650 with no title that would really help finish the XS400 off.. I know keeping the 650 together would be a good option but it takes 2 -3 years to get a new title. without the original owner to sign off.