My Seca 400 project

Hi all...

I Just picked up a Seca 400 as a project bike, lots to do as there is much damage from improper storage, and over the course of the project I'll likely have lots of questions and pictures to share. As I work away at this rejuvenation project I'll keep posting in this thread and maybe what gets posted by me and others will be of use to someone else with the same bike.

To start off I'll mention this is the first street bike I've had in 20 some years and ironically enough my last street bike was a Seca, albeit a 750 though. Before that I owned a Yamaha Vision 550, a Honda CB550 four, a Yamaha RD350 and the first basket case bike I dragged home when I was 13 was a Honda 150 Dream. In the 20 year span that I've not had a street bike I scratched my itch with a couple trail bikes and as of late a small collection of mini motos that my son and I race\ride at the kart tracks in our locale. Never enough though...the itch was just too itchy and I just had to have another street bike. This Seca 400 came to me fairly cheap and delivered, I also purchased it pretty much sight unseen too...bad move I know...but hey I wanted a project and I got one. So as I said above most of the damage on the bike is from improper storage and as you see in the one picture the chocolate milk looking stuff in the bowl is what came out of the crankcase. Experience tells me when oil is that color it's got water in it and I suspect water got in there because the bike had been sitting outside with no oil fill hole plug in it. The bike was complete though sans the battery so I guess that's a plus :lol: Anyway I've now got the bike indoors and the motor is out and on the workbench...pulled the valve cover last night and the cams, chain and other goodies under there look good with no signs of anything serious. Will be digging deeper into the engine over the winter to check things out and make what's wrong right. Going to chip away at stripping the frame this weekend so as to make neat little part piles under the bench and a long "To Do" and "Need To Buy" list. One of the things I know I'm going to add to the need to buy list first is a set of fork tubes, the left hand tube is pitted badly well into the wipe area and the other side is not much better off.

First question...

Does anyone know if the tubes from other Yamaha's will fit this 400?

I'm roughly measuring the originals with my vernier to be about 35mm OD, not sure of the length at all but I figure they'd likely be in the 600-650mm range. Would be nice to hear something else may fit as I've not seen any direct replacements of that year worth looking at in my area. Yamaha dealer says he might be (and that's a big MIGHT) able to get new ones but they are pricey at 260 each !

Here's the first load of pictures to look at, as you'll see the fork tubes are a real mess. The gas tank too will need to be stripped, blasted and coated, suspect it must have leaked going by the bondo plastered on the lower seams. The dents appear to have been from something falling on the bike. Seat is obviously in need of a new cover and some creative foam work too. If only the past owners had stored it properly :roll:













As you can see this bike suffers from fusebox rot too...lol




Cheers all...

 

A bit of a duh me moment...

Although my 400 is a Seca it is not an XJ...it's an XS400 RJ. I probably should have started this thread in the "Other Motorcycles" forum

Mods, feel free to move this thread if I posted in error...

 

You should be fine, the folks on here helped me get my XS400K (Maxim) up and running. A lot of the info her transfers to out bikes as well. My fork tubes are in similar shape, you could try e-bay, but that can be hit and miss. I do have a copy of the manual if you need any info in a hurry. I have pics and some of the issues I went through posted up here..Maxim Project

 

Hey, I've completely rebuilt, customized, modified two XS400J's so I know every inch of those bikes...PM me if you want any help. BTW, those tubes will be fine.

 

So you guys think the tubes will be fine? This could be good news

I seen some info on the net where a guy cleaned his tubes, which looked much worse off than mine, up and then used JB Weld to fill the pitted areas that were in the wipe zone. He reports that his forks don't need to be re-filled on a weekly basis anymore...

Hey ZaGhost I'm planning on ordering a Yamaha service manual after Christmas but if you have a manual handy I do have couple nagging questions that I'd like to ask if you don't mind...

1) Fork spring length specs
2) Fork oil amount

May sound kind of silly that I'm worried about the forks at this stage of the game but hey they are an important\expensive end of the bike so it's one of the things I'm going to get sorted out first.

Thought I'd add that like others my oil filter bolt is messed up bad, don't know why the PO or whomever attacked the thing with Vice Grips...geesh I hate those things and I don't and won't ever own a pair :roll:

 

Was just taking a break from stripping the frame and seen my feeler gauges sitting on the bench...thought I'd take a look at valve clearances just for fun

I have no idea what the factory specs are but with the lobes opposite to the lifters I get the following readings...

R intake = .002 slides nice, a .003 won't go

L intake = .003 slides nice, a .004 won't go

R exhaust = .007 slides nice, a .008 won't go

L exhaust = .008 slides nice, a .009 won't go

Please let me know what you think.



Cheers...

 

OK

Forks, Free Length for the springs should be, 561.7mm or 22.1 in.
Oil 263 ml or 9.3 Imp oz or 8.9 US oz
I did mine last, seals were shot.....
I thought about using something like a JB weld, but if a piece came loose, it would shred the seal in no time....

As for the filter bolt, i can tell you exactly what happened.... a PO over torqued it (only calls for 11 ft lbs), steel bolt in aluminum , 2 different expansion rates and a small 12 mm head on that sucker (it's quite large) the head on mine was ROUND!!
EMGO make a replacement with a 17mm head, much nicer.

Valve clearances
Intake 0.11~0.15mm or 0.004~0.006 in
Exhaust 0.16~0.20mm or 0.006~0.008 in

I need to check mine while she's down for the winter (hoping to get a few more days in yet, not looking good in the long run)

That should keep you busy for a bit... any more questions, just ask...

 

Thanks ZaGhost, much appreciated and I'll be looking at the springs in a few days. Wouldn't mind finding a set of Progessive springs to stuff in it now that I think about it, used a set of those in my Seca 750 and they made a night and day difference 8)

Well I've stripped most of the frame...got a few part piles now with more to come :lol:

Was thinking about the tank and what I'm going to do with it, seems after looking around I'm better of restoring it to my liking. Cost for a used one that's not much better off than mine drove me to thinking I'll just fix what I got and then I'll know for sure what I got if you follow me. Anyway the PO tried to seal leakage with a thick smothering of bondo on the outside and some hard epoxy looking stuff on the inside and the epoxy stuff is all puddled up and is as well chunking\flaking off. The lines drawn on the bottom is me getting ideas on how I might cut it apart so as to sandblast it inside and out real good plus I need to punch out some dents on the top. After I do this prep work I'll be sending it to these guys for final prepping, reassembly and sealing, they come highly recommended as one of the best fuel tanks restorers in the business.

Anyway here's some pictures...

 

Welcome, SteveG!

You're in the right place. Even though our baby Secas are technically XS's, they share a lot more in common with the XJs than with the other XS's (SOHC 400s and 650s, etc.).

I have an '82 Seca 400 that I commute daily on -- 15,000 miles worth over the last 15 months. I love it, and am glad to see you resurrecting yours from the junk heap.

I also have a 1983 parts bike which was left outside for 10 to 15 years (in humid and rainy sub-tropical Louisiana). It was running with good compression when it was parked outside after being traded in to a local bike shop. It was robbed of its gas tank at some point, and the forks and shock are totally useless now (flaking rust), but the front fender, tail section, exhaust and wheels are in pretty good shape if you need any of those items.

Its engine was sealed tight with all filler plugs, spark plugs, etc. in place, but I still got the same milky goo as you did when I drained the "oil". It is locked up tight, but hopefully can donate some parts to my spare engine project.

Anyway, welcome again and good luck. This site has some talented and knowledgeable folks who are always willing to share their gifts and experience.

Regards,
Herb

 

AHA!! a few more and we can branch off into our own DOHC XS group

WOW, the inside of the tank looks nasty, and I was worried about mine!!
Plan to redo mine over the winter as well...

 

Thanks for the welcome Herb and the heads up on an exhaust. Is that exhaust you have an original factory set? Mine came equipped with some slip-ons of unknown origin and at this point I have not decided what I'll do. A custom superbike style end can of my own design and getting a local pipe bender to weld me up a 2 into 1 pipe set would be cool 8) Looked at all the MAC 2 into 1 setups for this bike...YUK was my first thought :lol:

Yea my tank is a bit messed ZaGhost...lol...if only the rest of the world knew how to properly store a bike when it's not in use we'd be able to buy 25 year old bikes with mint tanks. Seen new tanks in stock at this European online shop but by time it landed at my door I'd have $500+ bucks into one that would still get rusty if not lovingly cared for. I've seen a few used ones too online and at the local salvage yard but the prices were $150 and up for something that was really not much better off than mine so if I sink some man hours and a say $200 for outside work into mine I'll have a better than factory rust proof tank.

Anyway gotta get back to work...

Cheers all

 

Steve:

Yes, the exhaust on my cadaver bike is the original factory unit. Some surface rust, but fairly nice and solid.

Good luck with the project and keep us posted!

Herb

 

Thanks for the info on the exhaust Herb...


So my machine is pretty much stripped except for the forks and front wheel...kinda stuck at the moment too with the swing arm as I need to pick up a couple bigger sockets to get the swing arm bolt out. Anyway I was bored tonight and was thinking about the little things I might do and the airbox came to mind. My airbox is pretty much fubar as the bottom was melted due to a small fire in there?? The side cover on the filter insertion side is missing too but obviously the airbox can't be completely eliminated as not only does it contain the air filter but it's also is used for securing the battery, brake light switch etc etc. So as the story goes I'd kind of would like to use some K&N's or foamies for air filtration, little more intake roar at WOT never hurt anyone either and it'd be a nice personalization touch too. Now getting those type of filters fitted with a stock airbox would be tight if not impossible and eliminating it completely screws me up for other things...so what to do??

HAVE SAW, CAN CUT... :twisted:

Pictures show my airbox after the rough cuts and yea I'll be cleaning it up more for appearance sake but in the end with what I've done I'll be able to mount the battery and the other things as they were and also have a ton of room to fit some nice reusable filters on the end of my carbs 8)







Cheers....

 

Taking a saw to the Airbox might not be the right thing to do for a Baby XJ-Twin.

You have a delicate balance going-on making power from the restricted Airflow present through the Airbox Intake Inlet.

Once you eliminate that ... you get a One-Way Ticket to Re-Jet City!
You don't have the leeway that a 4-Cylinder Bike offers. The Four's can be close and still Pop and make power.

You foul a Plug on a twin and you are one cylinder away from pushing it home.

Try getting the thing to run right the way it was built ... then, after you have added another bike to the stable you can ride while you play-around with the XS-400 ... Do your Mods and see what happens.

Pods are not a solution, really.
Pods can be a real headache.
On a lightweight twin ... they might be an Excedrin Headache!

 

Not too worried Rick, I've got a nice collection of jet drills and reamers to dial it in when the time comes.

Edit: thought I'd add this link to a DIY AFR meter, I've built a handful of similar units over the years for myself and friends that were mucking about with 2 stroke jetting and they do the trick quite well. You'll obviously have to scrounge up a good 02 sensor and position it properly.

 

i cut the snot outta mine with a rotozip. The factory diagrams show that the airbox should separate into two halves but you would definitely need some sort of MAGIC hammer to do it. All I left on mine was the battery tray, the two bolt holes under the seat mounts, and the little tab that hangs down that the brake light switch screws into. You must remove the swingarm to get the box out and then determine what needs to be saved and start hacking. I am running UNI foam pods PK-92 kit and 122.5 mains and stock pilots and she is a solid runner and starts fine...Oh, I also shimmed the needles with some 4mm washers. PM me if ya need any help.

 

Really the factory diagram shows 2 parts? That's nuts...lol...a MAGIC hammer would be needed to separate them for sure :lol:

I like those PK-92's, nice looking filters...

 

dwcopple:

It's nice to have someone that's been down the path ... show the way to those who are heading that way.

Please fill-in all the blanks on this job. I'd be looking to you for help if it were me; too!

 

Sccoped a decent looking set of forks on ebay, tubes look pretty clean and seller says they are straight with no visible leaks so for 90 bucks shipped I'll take a chance.

I think they do look much better than mine although the pictures were not the greatest :lol:

 

well, I'll take some pics soon but it is frickin' freezin' here right now with hellafied winds. But soon.

 

Nice looking set of forks, sounds like a good deal to me.

 

hope this helps...you can see the battery is inside on the trickle for the winter. I do still use the bolt on battery cover on that side...it is hanging down in the first pic. My other 400 is getting a tray welded in between the frame tubes for the electrics and battery...that'll be a sweet ride when that is done!!!

 

here is the bike...

 

Steve:

Regarding your fuse box rot -- take a look at the blade-type inline fuse holders.

Garden variety Buss ones are available everywhere, but for the real trick try to find some by Posi-Lock (or use the Buss fuse holders wired in with Posi-Lock connectors).

I've been using Posi-Lock connectors for the last few months as I've had to replace my pickup coil unit 2x, and plan to use them as I gradually replace all of the connectors on my 400.

They're somewhat pricey and hard to find, but I'll never crimp again!

Herb

 

dwcopple: Even with the airbox cut to oblivion it's still looks like a tight squeeze to get the PK-92' in there...they are one of the shortest set of pods on the market too. Nice looking ride btw, like the seat job...plan is to cut\contour mine down slightly when I recover it as I like to be flat footed when I'm stopped.

Thanks for the tip Herb, I've been looking at some mini fuse panels online...been eying this one with 4 connections, it's a marine unit with a water tight cover. Thinking I could cut the fender out a little to "sink" it some so as to be able to close the seat without crushing it. Be a while before I put the wire snake back in it though I fear...

Gosh...so many little bits of this and that to buy and do, there's a running bet in our house about how long it's going to take dad to refurb his motorcycle :lol:


ZaGhost there's lots of little goodies on eBay for our style of the XS400, I figure I got real lucky on the forks if the arrive looking as clean as the pictures show. Local salvage yards want 150 a side for decent ones and new tubes alone are anywhere from 120 to 250 worldwide! The last dealer I spoke with wanted 139 US$ per tube plus 40 bucks shipping...he said Yamaha in Japan shows 6 new units in stock.

 

I spotted some things on e-bay... found better luck with others with parts bikes
Some are willing to sell you thins they aren't using....
Just realized a while ago, I need a chain guard... otherwise planning some overwinter mods... new signals, brake lines, bars and grips maybe a seat mod and some surprises as well

 

Just a little update on where I'm at...

My eBay forks have not arrived yet although they have left the USA on a plane so I expect they should be here this week, am really hoping they are in as good a condition as they appeared to be in. I picked up a wicked deal locally on a new all black ceramic coated MAC exhaust system...180 bucks taxes included! I know I said I didn't want a MAC system but I was basing that statement on seeing nothing but all chrome systems...I'm not a chrome kinda guy! Anyway the all black system will fit the color scheme I have planned and the price it was offered at sealed the deal. I got the gas tank back from the metal finishing shop yesterday, I took it in to have the outside cleaned off and after I cut it apart I will be taking it back to get the inside cleaned up...along with the frame and a whack of other rusty parts. So as you'll see in the pictures the tank has a few holes but not to worry, old school body solder will be the primary material used to repair it. Also I've now decided that since I'm going to repair the thing primarily with solder I won't be cutting the bottom out as the heat generated while welding it back in will obviously play games with the body solder...even the lead free stuff that's got the higher working temps won't stand up to a TIG working in the vicinity. So the new plan is to cut a hunk out of the top side, well away from the style lines, that will give the metal cleaning guy enough room to do his thing inside and me plenty of room to get in and repair the leaky spots. What I'm likely going to do too while the top side is cut out is shape a new piece of metal and install a flush mount aircraft style gas cap in the forward center section of the tank...me thinks that would look trick and go with the theme I have in mind. Oh and another little note is that I stripped the carbs so as to have a look and man I dunno they look pretty sad inside and out! I tend to think that rather than throw money and time at them I may just pick up a set of round slide VM32's or 34's to adapt to the stock intake boots...every hot rodder knows CV carbs suck right :wink:

Anyway...I'll shut up now :lol:

 

And the rest of the pictures...

 

wow, I'd look for a new tank...that is gonna be alot o' work & bondo...if you are up to it...it's worth a shot I guess. GOOD LUCK

BTW...there is tons of room for the pods, I think it is just how the pics look. I can put em on and off just by reaching in the frame rails...

 

No bondo!!

...metal and lead is where it's at :wink:

New tank is min 500 landed at my door, used that will need repair\cleaning\sealing and paint ?? Screw that, work with what ya got and make it yours and make it nice 8)

 

How are you going to fix those holes ... Braze or Lead Loading?

 

Rick I plan to use lead for sealing leaks but I'm not approaching this in a plug it "ALL" with 10lbs of lead manner. I'll TIG in some well formed metal pieces on the really bad spots then seal the little stuff and smooth\seal any welded seams with lead. I guess I'll know better what the final plan is once I get the top off and get the epoxy blobs on inside blasted out as it's likely the major spots seen on the outside now will look much worse once the inside is cleaned. Sitting here looking at tank pictures from various bikes and pondering how to cut the top...thinking about if I should add some new style lines along the weld seam, where I want to position the flush mount fuel cap etc etc...lots of fun 8)

 

This the style of gas cap I'm going to use...only I'm hoping to find a completely red or black anodized unit. Brush aluminum might not be so bad either but NO CHROME!

 

Sounds good ... I like the Cap.

 

I want to see the finished tank.. I think it will look sweet once that is all painted and has that cap on there.

 

Forks I bought on eBay arrived today...what a deal!! No imperfections at all in the wipe zone so that find saved my bacon in a big way 8)

Tank progress...

Went on a little quest today to see if I could find someone local to modify the topside for the gas cap, lots of shops claim they do "custom metal work" but not one has an english wheel or even a good bean bag pillow and a proper set of mallets to recreate the top's shape. Even more frustrating is that only one of them has tig capabilities and none can or will weld with O\A...they all will mig up a plant stand for grandma in a hurry though :lol: I'll be damned if I'll let anyone attack the top or bottom of my tank with a mig, I'll buy an O\A rig and do it myself first! Head scratcher of the day was when I walked, tank in hand, into to the premier local shop that advertises on all our radio stations as being custom bike builders...I think they should reword the sales pitches to custom bike assemblers. They don't have the capabilities do any custom forming of sheet or tube and the lead tech guy I was directed to talk with instantly squawked about how much he hates tig welding! They had piles of off the shelf custom tanks and frames that other people made for sale though...tisk tisk...and here I thought they'd be the local equivalent of OCC.

 

You should take the tank right down to OCC and bust-in during a taping of the show yelling obscenities and asking what a guy has to do to get his tank fixed in These United States. Tell the Old Man that your going to hold everybody responsible for helping you out because you can't weld it up yourself and the guy who you brought it too said: "Why don't you take it to OCC ... them boys can do anything down there."

Then just cry and tell them you are sorry and leave ... conveniently leaving the Tank and a note attached to it saying something tear-jerking enough to have the Producers have Paul call his friend Jesse James and do it on an nepisode of Monster Garage!

 

Although sometimes I wish and regret I didn't I do take issue with places that advertise they do something yet when you know what your looking for you can easily see what it is they can do :wink: We run in to this all the time though don't we with mechanics, doctors, contractors and so on...I've had experiences and paid large so if it's an important task I want done I always investigate first.

 

Hey SteveG....Lockhart-Phillips makes a few different anodized gas caps in this style. Take a look through the Parts Canada On-Line Catalogue, and have your local dealer order one up!

Cheesy!

 

Thanks for that Cheesy...went to Parts Canada and then to the Lockart Phillips site and I'm eyballing the Goodridge unit pictured. You can get the flange and neck parts too 8)

I like the PP Tuning caps too...not as pricey as the Goodridge

 

No prob Steve.....Actually, I preffer the look of the PP over the Goodridge. Do they come in a Red Anodized finish like the L.P.'s?

 

$211.00!!!!

 

ACK!!!! I was looking for a possible replacement for my cap... guess I'll just replace the gasket

 

At least you Maxim guys can buy the rubber gasket separately. The only thing available for my Seca is a "cap assembly", which runs $40+ (plus shipping).

All I really need is a thin cork gasket which was INSIDE the cap mechanism. Mine disintegrated and clogged the cap vent, leading to fuel starvation problems.

I took the cap apart and removed the remnants of the gasket, and my bike runs fine now, but it does seem to weep a little gas from under the cap every now and then. It also seems to smell a little more strongly of gas when you first walk up to it...

The cork gasket was too mangled for me to determine what it used to look like, but I may eventually try to recreate it.

For now, though, I just ride.

Be safe-
Herb

 

Thought I'd post a pic of the ebay forks I got to replace the DOA units the bike came with...

The wipe zone is good on these ones, there is some minor pitting up near the triples...for 100 bucks though including shipping I'm not complaining. Funny the seller said no visible leaks...yea no wonder...there is no oil in them :lol:

 

Here's a pic of the new exhaust system, got lucky and found an all black setup which works for my planned color scheme. Was looking at the removable offset baffle system they used in the muffler and I'm thinking this thing is going to be way loud as there is no packing material of any kind in there. Maybe when I get my welding rig setup I'll cobble up a tube and packing type baffle to mellow out the sound. Also included is a picture of a tank I'm going to go pick up next weekend, yes I'm still going to repair and customize mine but I lucked into this good non leaking and dent free one for 50 bucks and given how rare these tanks seem to be I'm going to scoop it. Pictured too is my swingarm bushing, it and the needle bearings are FUBR so I have to get some replacements. Bearings are cheap, about 5-6 bucks each at my local bearing supplier but the bushing itself is pricey...was quoted 60 bucks at the local Yamaha dealer. My frame, cut apart tank and some other parts are going off to the sandblasting shop this week so all that cleanup work should be out of the way finally. Will soon be time to start putting the frame back together and then get on to inspecting and sorting out the engine...


Cheers 8)

 

since you arent using that tank would you be interested in selling it?? or know where I could find one?