Just picked up a 79 XS400

[bodean]

And I know sweet @#$2 all about points and carbs, I've taken the carbs out and have started cleaning them up but I am only getting spark to the one side, I've tried switching plugs, both fire and I have swapped coils and both will fire. So from what I have read its a timing issue with the points? Go easy I am a rookie with these things and just trying to breath some life back into this old bike.

Thanks for any help you can give me.

[bodean]

So after doing a lot more reading, and getting a manual I have managed to gap the points and am now getting a nice blue spark out of both plugs but I don't think the timing is correct, at all. The right side begins to open just around the time it get to the RF timing mark, but the left side is already open and when the left side does open it is no where near the LF mark almost seems to be 180 off, is it possible I am doing something wrong? or could the timing be off for the motor? I hope you can understand what I mean. Maybe some pictures would help? I have yet to actually try and start it. But I'm thinking it wont run if the ignition timing is out of whack.

[drewpy]

So after doing a lot more reading, and getting a manual I have managed to gap the points and am now getting a nice blue spark out of both plugs but I don't think the timing is correct, at all. The right side begins to open just around the time it get to the RF timing mark, but the left side is already open and when the left side does open it is no where near the LF mark almost seems to be 180 off, is it possible I am doing something wrong? or could the timing be off for the motor? I hope you can understand what I mean. Maybe some pictures would help? I have yet to actually try and start it. But I'm thinking it wont run if the ignition timing is out of whack.

I'd invest in a xenon strobe lamp as it times the ignition spot on when on tick over.

(try ebay only £20)

you need to check the heal of each contact for wear as this will send off your timing adjutment! or just buy a new set of contacts. don't forget that the firing is done 180' as the pistons move up and down alternatly not together a la brit bikes!!

[bodean]

I'd invest in a xenon strobe lamp as it times the ignition spot on when on tick over.

(try ebay only £20)

you need to check the heal of each contact for wear as this will send off your timing adjutment! or just buy a new set of contacts. don't forget that the firing is done 180' as the pistons move up and down alternatly not together a la brit bikes!!

The contacts look good, the bike only has 8000 miles on it. it almost looks like the cam for the contact is out of time, is that a possibility, like i said i don't know much about these things. in order to use a strobe light wont the bike need to be running?

thanks again.

[drewpy]

The contacts look good, the bike only has 8000 miles on it. it almost looks like the cam for the contact is out of time, is that a possibility, like i said i don't know much about these things. in order to use a strobe light wont the bike need to be running?

thanks again.

tick over does mean the bike is running at idle!

8000 miles on a set of contacts may need renewing!

[bodean]

tick over does mean the bike is running at idle!

8000 miles on a set of contacts may need renewing!

Drew I think you may end up walking me through this whole thing lol. So I think I have the ignition figured out the contacts just begin to open up as the in crosses the firing mark. Got it fired up pretty quickly, seemed to be idling fairly well but when I went to give it a little gas it would stutter out and die, tried this a few times before I realized fuel would spray out the petcock as I opened the throttle and the bike would die. So I am assuming a meed to rebuild the petcock? Also the rear wheel seems to be very hard to turn, neither of the brakes are working, I'm going to fill them with fluid and try and bleed them, could it be the rear calipers are causing the issue, or rear wheel bearing?

Thanks so much for you time and help.

[bodean]

So I pulled the petcock apart and the diaphragm looked fine, but the small rubber seat it sits in (looks like a hat) as a few tares in it, I've been checking out some rebuild kits and none of them seem to have this seat. Do I need to replace the whole petcock? or is there more complete kits out there?

[drewpy]

So I pulled the petcock apart and the diaphragm looked fine, but the small rubber seat it sits in (looks like a hat) as a few tares in it, I've been checking out some rebuild kits and none of them seem to have this seat. Do I need to replace the whole petcock? or is there more complete kits out there?

ebay is your friend

http://cgi.ebay.co.uk/YAMAHA-XS400-XS-400-FUEL-TAP-REPAIR-KIT-206347_W0QQitemZ400057646583QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item5d254b3df7

the calipers will need stripping ie take out the brake piston and check for rust. you can get stainless pistons from germany 20euros or get someone to make a set!

also sounds like the carbs need a strip and ultrasonic clean with new needles etc

[bodean]

ebay is your friend

http://cgi.ebay.co.uk/YAMAHA-XS400-XS-400-FUEL-TAP-REPAIR-KIT-206347_W0QQitemZ400057646583QQcmdZViewItemQQptZUK_Motorcycle_Parts?hash=item5d254b3df7

the calipers will need stripping ie take out the brake piston and check for rust. you can get stainless pistons from germany 20euros or get someone to make a set!

also sounds like the carbs need a strip and ultrasonic clean with new needles etc

I'm going to try and remove and strip both brakes today, see if that frees up the wheel.

That kit from ebay still doesn't have the damaged part. It looks like a top hat almost, maybe it doesn't need to be replaced one you rebuild it? I'm not sure.

Thanks for the link to the ultrasonic, I may have to look into that a bit more.

[BRB]

I'm going to try and remove and strip both brakes today, see if that frees up the wheel.

That kit from ebay still doesn't have the damaged part. It looks like a top hat almost, maybe it doesn't need to be replaced one you rebuild it? I'm not sure.

Thanks for the link to the ultrasonic, I may have to look into that a bit more.

The petcock kit you need should be the top one shown on the link.

http://www.siriusconinc.com/search_result.php?make=YAMAHA&model=XS400&part=Fuel+Petcock+Repair+Kits&partno=&x=56&y=12&search=search

As far as cleaning your carbs, a local carb rebuilding shop may have a ultrasonic tank (preferred) or you can by some Yamalube carb dip which mixes with water and a large second hand electric slow cooker (check the wattage, mine is a 475w) will do the trick.

[bodean]

Yeah it appears to be a carb issue, I rigged up a gravity fed fuel tank and blocked the vacuum line on the carb, its started up after a couple kicks but would only idle on one cylinder, but when I sprayed carb cleaner it the other intake both cylinders ran. So I guess an ultrasonic is in order.

Is there a way to tell if the master cylinder needs rebuilding or replacing, or if its just not bled properly. I can not get any pressure out of the front brakes, I filled the reservoir with fluid and opened the bleeder...when I held the brake the bleeder with flow but closing everything and squeezing the brakes repeatedly, open bleeder, squeeze, bleeder, repeat...did this for awhile and nothing.

Thanks for all the help and time. I know this thing will run...I've heard it, just needs a little work still. Also the back brakes are sticking, I loosed off the caliper and it freed everything up, but when I press on the brake it sticks again.

[bodean]

So little update, after doing some research I discovered boiling in lemon juice was highly recommended. So that is what I did. Couple kicks and it started up...ran poorly for a few seconds then its smoothed right out, dropped it to half choke after 45 seconds or so, then to no choke. Idled right around 1300 and would rev up cleanly when I would give it some throttle.

Going to rebuild my master cylinder and petcock, get some tires and a new chain and sprockets and ride the hell out of it when I'm not on my Aprilia SXV.

I will be sure to keep those interested updated.