Gas tank: wobbles, surface rust inside

[sirdurden]

So I picked up a 1979 xs400 last night. The tank seems to be a little loose on the frame. Also, I peered inside the tank for rust. The bottom has a fair amount of surface rust. Sides on the interior are spotless. Still need to clean? I intend to splice an inline fuel filter between the tank and the carb very, very soon.

My Vin is a 2L0******, and title says 1979 so I therefore have a xs400f? The tank seems different than what I have seen on similar bikes in online searches.

Also, SOHC?

No rear turn signals either so I have to figure something out there. Fronts are led and need resistors to reattain proper current.

Any help is greatly appreciated!

 

[arfstrom]

Yup, In-line filter, I used Kreem first, then I forgot to un-block the vent hole on the gas cap. so the Kreem fail due to my own fault, then this time I used Por-15. Use Amazon for review pricing comparisons. Kreem had a 3 bottle system kit, and Por-15 has a motorcycle specific kit. beats paying 120 off of ebay for a new tank. Youtube has some videos you can query to get the rust out.

The LED's are OK for the Tail/Brake lights. Untill your ready for the the "Piece of Resistance" Leave the incandescence in there. There is a active postings on the LED's and it seems he is going to make a How-To with a relay. I am hoping he will find out that its the shared ground???? So it google, and search, there is alot of stuff on flipping to LED's on our website, as well as anyother XS400 website. I bought my led's off of EBay, and now I am just waiting for the time to mess with it, and other projects. I have a relay queued up on Amazon, but I am not ready to buy it.
Tobie

 

[sirdurden]

Thanks for the reply.

So I finally got out on the bike. Couple things.

1) Bike started right up last night.

Switch turned to on, kill switch to on/run, kick stand up, clutch in, and pressed the electric start. Nothing.

Maybe the battery is dead and therefore bad. I tried the kick start which worked only if I had the clutch released (obviously in neutral). After a few weak kicks, the dash lights came to light as they should have when the key is in the on position. Am I missing something? Also, I have an on, off, and some short acronym on my chock.

I turn the chock to off when I am done riding correct?

Sorry, I am very, very new to the motorcycle world and tried some searching without very clear answers.

 

[arfstrom]

1) Bike started right up last night.

Coool!

Switch turned to on, kill switch to on/run, kick stand up, clutch in, and pressed the electric start. Nothing.

Leave the clutch alone. If the neutral light is on, you don't need to clutch in anything. On the other hand, supposely Clutch in, and Starter button should fire up. So Green light on, you can Kick start it, or press the button if your that lucky to have a electric starter.

Maybe the battery is dead and therefore bad. I tried the kick start which worked only if I had the clutch released (obviously in neutral). After a few weak kicks, the dash lights came to light as they should have when the key is in the on position.

If the battery is less than 10 volts, I don't think it will do anything for you. if you were driving, and the battery falls under 7 volts, the bike dies.

the dash lights came to light as they should have when the key is in the on position. Am I missing something? Also, I have an on, off, and some short acronym on my chock.

I turn the chock to off when I am done riding correct?

Sorry, I am very, very new to the motorcycle world and tried some searching without very clear answers.

Alot of that seems to be personnal preference, alot of people start to feel sheepish cause they never use the kill switch, then they do it once, and the next time they wanta go somewhere, they will forgotten the kill switch was on. and complain, and kick the bike, and then they will see the kill switch. Its allways funny when its not Me Take your time, read everything. Jump in when you got a question, and no one has answered it recently. Good luck Tobie

 

[Scorpio1963]

That tank is not proper for a 79 year model.It is an older style tank that was modded to be used on the frame.

 

[sirdurden]

Thank you for your advice. Turns out the negative terminal of the battery lead wasn't tight, not even close. Tightened it down and all is well.

While it had it apart I managed to rewire that the tail and brake lights. They now work well.

I over paid for the bike , but I am glad she's mine.

So I sat on the bike, got it level and the very tip of the dipstick and some rather dark oil. I guess I will do an oil change tomorrow night and skip riding to work tomorrow

20w50 is what the manual says for my bike. Obviously things have changed in thirty years. Recommendations? I read some viscosity of diesel oil works too. No synthetic since we have a wet clutch and all.

 

[sirdurden]

That tank is not proper for a 79 year model.It is an older style tank that was modded to be used on the frame.

Yeah I caught onto that today. Ended using a couple bushings to snug the fit up. It is better so I think that it will remain as so for now.

 

[arfstrom]

Alot of us are using Shell Rotella 15w40. Its 3.96 at Wallmart per qt, or 12.97 for 5 qts. do a search on here for Rotella, Synthetic, I am sure there are people doing the Synthetic. The code to watch for is JASC MA So that is the main thing. MA is for Wet clutch. I found Auto parts store here in MN "Orielly's Auto Parts does carry the right oil filter. check online for which one is closest to you.

FRAM® Extra Guard® - Motorcycle Oil Filter
Part Number: CH6003
5.99

as long as your at it, new plugs goes a long ways.

NGK Copper Core - Spark Plug
Part Number: 5534
$2.49

 

[sirdurden]

Alot of us are using Shell Rotella 15w40. Its 3.96 at Wallmart per qt, or 12.97 for 5 qts. do a search on here for Rotella, Synthetic, I am sure there are people doing the Synthetic. The code to watch for is JASC MA So that is the main thing. MA is for Wet clutch. I found Auto parts store here in MN Orielly's Auto Parts does carry the right oil filter. check online for which one is closest to you.

FRAM® Extra Guard® - Motorcycle Oil Filter
Part Number: CH6003
5.99

as long as your at it, new plugs goes a long ways.

NGK Copper Core - Spark Plug
Part Number: 5534
$2.49

Yeah when I checked the oil (sitting on it) the dipstick had almost no oil on it. People really don't take care of anything do they?

Sigh, I picked up some Rotella 20W50 at Walmart as well as a drain pan. Ran to O'Reilly's after confirming they had the filter in stock. I show up only to be told that they don't. Lame. So, thanks to your fram part number I called around and managed to a comparable Wix in town for like $8.

Get home, review the manual, and go to loosen the oil plug. Nada. That things is seriously seized. I emptied what I could out via the port for the mesh filter on the bottom of the crank case. Switched out the filter and the o-rings and put the oil in.

Overfilled by a small amount. Long day combined with the urge to ride resulted in the mistake of checking the level on the kick stand. Sat on the bike for a couple minutes to let the oil settle. It came in just above at the high mark. Obviously I will check in the morning now that the oil has cycled after tonight's ride (first one ever!!!).

My headlight is wonky to the left and the previous owner removed the rear turn signals while installing LED turn signals in the front without taking the time to do it correctly.

Honestly, I just want to pick up a front and rear set of incandescent. I like the bike, don't get me wrong, but it is my first and will surely be subjected to all sorts of noob mistakes. Therefore I don't feel like putting a ton of money into it but just enough to get it safe/legal

Anyone have suggestions for a signals (incandescent)?

Also, the petcock what are "PRI" and "ON". Really dumb question but I assume that "PRI" is prime for cold starts and that "ON" is for one the bike has started/warm. What should I leave this on when done riding?


This community has helped me so much in the first few days of ownership. Thanks again for all your help!

 

[arfstrom]

Anyone have suggestions for a signals (incandescent)?

1156 the type of Turn Signal lights
1157 the type of Tail lights.

Also, the petcock what are "PRI" and "ON". Really dumb question but I assume that "PRI" is prime for cold starts and that "ON" is for one the bike has started/warm. What should I leave this on when done riding?

Yup, your right. Pri = Priming, On is On, Res is for when you run out of gas, you can go another 20minutes i think.
Unless the PO put in a valve, the you On position is is fine. as long as everything is working, you can check it out buy pulling the fuel line off the carb. if it stops and you still have a lot of fuel in the tank, then its working. If it keeps draining, then you will need to rebuild the petcock. or buy a new one, or put in a new off switch.

My headlight holds to the left a little bit. its not bad on my bike. Double check the Rotella, Is that the synthetic model?

 

[willem]

Pri is not for cold starts, though. It's for filling the fuel bowls after you've emptied them, basically only need it right after maintenance (during which your carbs came off or you drained them). Or when you want to drain your tank of course.. Other than that yes arfstrom is right about the petcock working that way. It actually operates through the vacuum in your intake boots, there is a vacuum line from your petcock to the left intake boot of your cylinder. When your engine 'sucks' on this, the petcock opens for fuel flow in the ON and RES positions. PRI just bypasses this vacuum-switch and makes fuel flow freely at any time.

 

[sirdurden]

Today's progress:

Checked the oil this morning. The level sat right between the low and full marks on the dipstick.

Added some DOT3 brake fluid as mine was pretty low. Fluid was milky so the brakes need to be bled. Never done this before and I don't have a torque wrench to tighten everything back to spec.

Checked tire pressure as I had a bit of a wobble on the highway. Nothing scary but seemed like something was off. The front tire was 7lbs over recommended pressure. Rear tire was right on spec. Noticed the tires are quite weather checked and am having trouble finding the 3.0 x 18 (front) and 3.5 x 18 (rear). What is the aspect ratio a xs400f?

Any tire recommendations? I would prefer oem sizes to retain handling and what not.

Also, I need the entire turn signal assembly (lens, housing, socket, and wiring). One of the brilliant previous owners decided to remove the rear signals and ghetto fab led signals to the front. I would rather just get some incandescent signals in there. I'm going to check locally tomorrow but am not holding my breath on finding a decent deal.

Also need some grips as the left one is totally split and barely hanging on.

I had another question but can't seem to recall it atm.

 

[willem]

What tire pressure did you take as 'spec'? Cause the manual is probably not giving you the right pressures. That pressure is for stock tires, and nowadays tires work better with different pressures. You should look up your tire specific pressures.

 

[sirdurden]

I'll have to check out the sizing but tire specific pressures are necessarily proper either. A lot depends on loading but I will compare the factory specs vs tire.

 

[xschris]

110/90-18 on the rear for the 79f 90/90-18 on the front.

 

[sirdurden]

I called a couple shops in town and found some incandescent signals. They're actually just running lights but are amber so no big deal since all the work is done prior to the light anyway. I found a cheap set of grips just to replace the wore/torn set onto the bike as well. So I head home expecting to take care of this stuff tonight and be riding in the morning...

BUT

I got the front signals wired in and they turn on but do not cycle (flash). I searched the forum and am a little apprehensive on just going bonkers with the credit card. By no means am I wiring guru. I have looked through the wiring diagram for the xs400f and cannot for the life of me figure this out.

I CANNOT HERE THE RELAY CYCLE, I.E. "CLICK"

Let's first start with my newly purchased lights. Incandescent bulbs that are 12V and 23 Watts. Not enough current draw to cycle the relay? What are the oem bulbs for this bike? The lights get very, very hot quite quickly which is abnormal.

I looked through the fuses earlier this week to find them in proper order and the connections looked just fine. Also the bike starts without much (if any) hesitation when started with the electric start so I don't feel that the battery is trash.

What am I missing??

Here's a picture of the front wiring:

The dual brown and dual green are the positive wires I am wiring to the turn signal along with a ground.

Issue #2

I don't have enough connections in the rear to install both left and right signals. The green wire is connected to a black wire while there aren't any negative lines available.

Sorry for the image quality:

Sigh, I guess I won't be riding tomorrow morning.

Oh and I'm a total moron and ruined my new grips during installation (at least they were only $7).