81 400 project

[natboh]

Wanted to finally post here been a member for a few weeks reading everything I could to get started. Picked up an 81 xs400 a month or so ago while I was looking for a project.

Here is the bike as a bought it. Didn't run and had quite an exhaust needs a seat turn signals and brake lights and front brake caliper



Took the carbs apart and cleaned them out kinda got it running but not the best.
Bought a parts 81 and the first thing was putting the stock exhaust back on and definitely think it looks better
Also got 3 carbs with the parts bike so cleaned one up and put it on. Now it starts up first kick just need to do fine tuning.


Working on a seat now. Got the base made and will do some fiberglassing over the next few days


Used some thin dowel rods and hot glue to get an outer profile for the sides of the seat. Hot glued the start and finish of the dowel in place and pulled them into shape with some thin wire

 

[natboh]

Got a chance today to work on the seat a little more. Got the outer profile finished and filled in with some foam to shape it out before covering with duct tape. Hopefully will get to fiberglass tomorrow

 

[natboh]

finally had some time to get some work done.

plenty of take and painters paper


couple layers of fiberglass mat about 6 all together







after i got it trimmed down i picked up some carpet padding from the local flooring place they had some extra cutoff bits they were happy to get rid of.



couple layers of foam and sanding to get the right shape

still have a bit of trimming to do but starting to look like a seat

 

[HoughMade]

Looks like a fun project. I like the fiberglass work. Keep us posted.

 

[natboh]

Thanks it's a lot if fun to work with. Used to do a lot of subboxes and speaker pods so it was nice to work with again.

 

[natboh]

 

[natboh]

Took a break from the seat an worked on the brake light. Found an LED light that I liked and forgot to double check the size. It was about an inch too wide so I had to stretch the fender for a good fit. Bit of cutting and welding and it tucks right in. Needs a thin coat of filler and some sanding next

 

[natboh]

havent kept up on posting so going to try to get caught up over the next few days. so far ive finished the fender, turn signals seat, odd wiring and now just trying to get the gremlins out out of the carb.

 

[natboh]

for the rear turn signal pods I found some old map reading lights at a car show for about 5 buck. the leds fit right inside

 

[natboh]

I have a buddy that does auto upholstery repair and he insisted on covering it for me. turned out absolutely amazing and is by far the nicest part of the bike lol
originally I was going to do a plain black wrap but the leather and pattern really make it stand out

 

[natboh]

the exhaust was really scratched up and had alot of speckled rust so i wanted to clean them up. also i thought being chrome they stood out too much. I used rustoleum high temp matt paint. after i cleaned and painted I improvised with my kiln to cure them properly. worked out pretty well. I hung them from the ceiling to make putting fiber wrap on them easier

 

[natboh]

Been a while since I've had time to work on the bike. Switched out the front forks and rear to put the spoke rims on and also replaced the steering bearings.

I decided to try a different exhaust. I had a spare set of already hacked exhaust pipes and two shorty mufflers from a yard sale two end pipes from a buddy. Got them welded up and fiber wrapped to cover the welds. I still have the stock exhaust if I want to go back

And now tuning questions. It sat for a year so I gave the carbs a quick
Clean I'll go completely through them later and am replacing the throttle assembly and cables they are sticky. The carbs were not balanced or even close but it ran and I like the sound. I am keeping the airbox stock.

I'm guessing once I get the time to really tune it I'll have to go up on the jets and the idle screw as well? In not sure what size they are but but everything was stock

Any input would be a great help thanks!

 

[natboh]

Run into and interesting problem. I realized it's only running one the right cylinder. So I replaced the left coil and plug wire with a parts one and no change. I did notice it would fire the left cylinder if the cap was half on.

So I pulled the plug cap off while it was running so it was just the plug wire thinking the cap was bad.

Here is where I get lost. If I have the wire about 3/4 to an inch out it'll arc and the cylinder fires are it idles somewhat smooth. But if I go closer and have the wire touching the top of the plug it won't fire

 

[natboh]

I'm going to get new plugs caps and wires before I start anywhere else but that just seems odd to me

 

[cbrfxr67]

Kick a@@ progress. Just read the whole thing. Can't wait to see more of it come together. That seat is sweeet,... I dunno on your wire deal but hope you get it sorted out

 

[natboh]

Thanks! I'm really hoping to have it ready for spring. Just spent some time on Google and figured out the plug cap had a resistor that went bad and the one I got off the parts bike had no resistor so didn't run either. So going to pick up new ones and fresh plug wires and hopefully that'll be a step in the right direction

 

[natboh]

Got to Play around and start the bike trying to get an idea about what I need to tune it. Saw when it backfires there was a gap between the carb boot and engine in the one side that didnt want to run. The boots had a gasket which I've never seen used before on a boot but is this a common thing?

 

[xschris]

These boots use a gasket. If your boots have cracks it's a good idea to replace them as well. Aftermarket boots and gasket sets can be found for cheap on ebay.

 

[natboh]

Thanks! The boots are in good shape luckily but the left side wasn't screwed down snug so it was letting some air in. I forgot to check the carb jets today to see what size I have and what ones to order to start tuning

 

[natboh]

Just opened up the carbs and here are the jets I have
Main 135
Pilot jet 42.5
Pilot air jet 155


I'm I'm thinking going up one on the pilot to a 45 to see how that works as a start.

I'll order two different sizes of jets for the main and pilot unless anyone here has a set they want to part with.


Should I have to do anything with the pilot air jet?