78 Rebuild

[ohnomogan]

Hey, guys. I’m a newbie here. Just looking for some tips on my first rebuild. First up, I’m looking for a carb rebuild kit. I’ve checked a few out on eBay, but I’m not finding many that match my year. Any suggestions on good sellers/etc?

 

[NewHavenMike]

Welcome. You can find rebuild kits here:https://www.siriusconinc.com/pro-detail.php?pid=&product_id=712

That seller is also on EBay. Ive used these kits before and theyre good. Buy only authentic Mikuni jets if you end up needing those as well. The rebuild kit that I linked comes with jets but Im not sure that I used them or if my rebuild kits even came with them.

Tips on rebuild, take it slow. Dont tear everything apart at once. Keep your parts with the carb body they came off of. Do not soak the carbs in solvents when you still have rubber bits/seals on them.

After you get the carbs clean, do it all over again. Then do it once more, and then do it again.

Oh, and be sure to get a manual and read as much as you can.

 

[sandmanred]

Look for the write up in the tech section about carbs. It takes you step by step through all the things that need to be cleaned. My carbs didn't get work right until I followed these instructions.

http://www.xs400.com/forum/showpost.php?p=64401&postcount=17

and more info here

http://www.xs400.com/threads/carb-cleaning-carb-tuning-links.13321/

And check your rubber mounting boots. Any cracks or leaks in the boots or the vacuum connections that come off them will mess you up too.

 

[spectra]

Welcome and well listen to the above posts...................the carbs are the number one thing with these little bikes..............

Now if the girls at sirius would just show up and work on the bike the world would be good

 

[ohnomogan]

@NewHavenMike Awesome, thank you! I saw his stuff on eBay but couldn’t tell if it was legitimate or not because 90% of the product pics were of the girls haha.

 

[ohnomogan]

@sandmanred Thank you! And yeah, the boots are pretty much destroyed with cracks all the way through, I’m gonna need to find new ones as well.

 

[ohnomogan]

@spectra hahahaha well I’m a girl working on a bike, so don’t lose hope!

 

[spectra]

@spectra hahahaha well I’m a girl working on a bike, so don’t lose hope!

Well that's even better these things are not that bad just take your time and remember no question is a stupid one.......we all started out not knowing a whole lot on these and well at least I have learned a few things.......

Good luck and keep the pics coming of the build.

 

[NewHavenMike]

NOS carb boots are a bit hard to find.. I managed to come across a NOS set on EBay a while ago and I picked them up. I didnt even need them as I have a couple sets of repro boots... After tinkering with these bikes for a while, you kinda have to buy whatever you can when you see it available. If I buy one gasket, I make sure that I buy a couple more to keep a small stock of parts. Youll end up just knowing what you should need and what you should buy as an extra.

Youre gonna want to have a couple spares of sidecover gaskets and the rubber seals on the oil filter housing and a couple spare sets of ignition points. For me personally, if a leak happens or i need a part, I like to have it on hand and not wait a week for a simple gasket.

Get more pics and im sure we would all like to know what your plan is for the bike.

BTW, you can find a lot of parts you need right here in the classifieds. Ive purchased a bunch of parts from other forum members.

Owning any motorcycle that isnt "modern" is a labor of love. The maintenance must be upkept by the owner and the owner should know every nut and bolt on the bike. You should know what every sound means and what that particular vibration might be or if your timing is off by a couple degrees. This is just the surface and its a ton of fun...until it drives you insane lol

 

[ohnomogan]

@NewHavenMike Thanks for the heads up! I saw 2 full boot sets on eBay that may work, although they’re slightly damaged from normal use. The ad claims the clamps seal the little cracks, but I’m a skeptic at heart and don’t know if I should go for it.



That’s what the bike looks like right now while I figure out what all it may need repaired, replaced, or just cleaned up. But first I’m trying to just get it to start.



My goal is to have something similar to this one here, except possibly with air pods to open it up more underneath. It’s gonna be a lotta work, I know haha. And this isn’t just my first rebuild, it’s my first bike, period. Total newbie here. I haven’t even learned to ride yet. I’m using the experience to teach myself all the ins and outs of the bike like you said.

 

[xschris]

Don't buy used intake boots!!! Lots of repop new ones for cheap out there. Those will also include new gaskets also. Tourmax is a good one from what I have heard.

 

[xschris]

https://www.ebay.com/itm/intake-man...=item2cace3f0f1:g:iu0AAOSwDcZbNpPD:rk:11:pf:0 I have purchased stuff from this guy before.

 

[ohnomogan]

@xschris Thank you! I’ll check those out. Like I said, I was a skeptic about buying a used set.

 

[NewHavenMike]

The repro/repops are fragile. I have them on my bike now. The first set I had got ruined when I installed the carbs and didnt notice until I had to remove the carbs again.

It helps to seat the boot on the carb for a day or two and let the rubber conform to the carb. Theres a small ridge inside where the carb mounts to and this ridge is easily torn when you insert the carb. Other users here may advise against this, but I used a bit of old bearing grease on the carb and boot to help the carb get into place easier.

I dodnt even think I needed to use a ratchet strap to get it all in place.

 

[xschris]

Was that with a xs360 carb? They are made a bit different than the xs400 carbs. The with is the same but the lip is different. Also I know of you use the xs360 boot cage/carb support the fit is tighter. I use those on all the carbs. I have never used repop stuff but the cost if far less than any oem stuff. I lucked out a while back and pickup two sets of oem ones for $12.50 a boot shipped. I use a small board between the frame and carb to get them in and and little of Armour all type stuff as a lube.

 

[NewHavenMike]

Yes I only have 360 carbs. The aftermarket boots were probably xs360/400 general parts. I usually start my search for parts with the part number, which would be 1L9 in my case. I am taking the carbs off for Winter soon Ill have to double check that fitment. I do know that the carbs bottomed out in the boot so they must be a good fit.

 

[Petew]

I have used repop boots on all 4 of mine and they work great and don't leak at all. I wet my finger with motor oil and spread some lightly inside the lip of the boot and they pop on. I admit I have used the board method like xschris does.

 

[The Reverend]

Hey guys,

I'm helping ohnomogan get her bike up and running and we have a few questions.

We've identified which model she has (thanks to the thread on this forum that helped us!) XS400se2e.
So,
1. the rebuild kits y'all have recommended in this thread... will they fit her carbs?
2. Also, if she gets pod filters, is there a set out there that doesn't require re-jetting the carbs?
3. She purchased spark plugs at autozone and the guys there sold her a set of ac delco r42xls. are these compatible?
4. Any insights on fuel line?
5. I'm also having trouble tracking down a battery that will fit in this thing! Who knew it would be this hard to find a battery? Any insights there would be appreciated also.
6. xchris, we're interested in the kick lever you mentioned to me on the other thread.

Thanks all! We'll be getting a Clymer manual in the next few days so we don't have to keep bugging y'all!

 

[NewHavenMike]

1. The rebuild kits will work as long as you purchase the kits for the specified year of the bike.
2. ANY change to intake or exhaust will almost always require rejetting and more tuning. Pods are also junk and very hard to get dialed in.
3. Never listen to anyone at the counter of the autoparts place. They know nothing. Ive only ever used NGK BP7 and BP6 plugs with resistor boots. Ive used the NGK iridium equivalent plug with non resistor boots as well. If they don't have the plugs I want, I either go to another place or order them online. Youll need about 10 pairs of plugs if youre tuning and jetting so stock up on them.
4. Ive ordered fuel line from Dime City and I also use an inline sintered brass fuel filter.
5. I use the smallest AGM battery I can buy. I use whatever the store brand is that Pepboys, Autozone, or Oreilys carries. The smallest you could probably go and still keep the electric start will probably be a 120CCA, which is what I use.

 

[xschris]

Stick with stock boxes and filters. Tuning will be far easier and the bike will run much better. NGK bpr7eix plugs with non-resistor caps work well.