What's the problem? Coils, wires, plugs, carbs, VR???

[FIZR]

Ok, since I bought this bike a few weeks ago the bike has had a hard time going past 5-6K rpm when riding. Granted, I've ridden it without the airbox on because it didn't come with one. I did pick up an airbox a few days ago and installed the boots onto the carbs (since the box would not go on) and tested it like that(probably made it worse since the carbs had a less turbulent, less restrictive path for the air to flow through). Anyways, the bikes torn apart right now. Just trying to make sure I cover all my bases while it's apart. The plan is too rebuild the carbs, clean up and re-gap the plugs, maybe change the coils, wires and VR???

While I'm at it I might as well clean the tank out and put in a new fuel filter.

From the looks of the swing-arm near the lower shock mount the guy that had this thing before me just slapped some paint on it(everywhere except there) after the bike had sat for who knows how long?

Any thoughts?

Sorry for the elongated post... need sleep.

[yamaha_george]

hi,
If you are looking to give it a proper service change out all the liquids on the bike. clean gas in a cleaned tank, filter,pump, gas tap. fresh oil & filter , fresh brake fluid,& coolant.

The VR if the old tin can & rubber type replace with a late model 6 pin VR (you ignore the center top pin between the ground & live line.

Fresh plugs gapped correctly

Carbs cleaned especially the brass jets use thick nylon fish line if you use any kind of "poking" device NOT metal pins/rods / wire.
set the float hight (see Rage Digitals natty tool for this)
And then synch the carbs statically then with a synch tool with the bike running.
If you need a synch tool there is a WIKI on how to make one on this site .

If the rear shock & its knuckle are in crap condition clean them up replace bearings if required and re-pack with grease for sure.

[thatkid]

Don't buy coils wires/leads nor plug caps until you carry out a simple no cost test.

Ignition OFF, disconnect the coil low tension wires (White and Yellow connectors)

Test the primary windings @ the coil solder joints, factory spec is 1.8 to 2.2 Ohms

Now check the coil secondary windings/plug wires/leads
The secondary windings are tested between the ignition/spark plug wires/leads. Remove the spark plug caps (unscrew counter clockwise). Connect an ohm meter between #1 & #4 plug leads, then #2 & #3 plug leads factory spec is 9,600 to 14,400 Ohms. If they are out of spec (high reading) trim 1/4 inch off the leads and retest, it's probably the leads that are @ fault, failing that the leads can be replaced.

Now check the spark plug caps, factory spec is 9.000 to 11,000 Ohms.

All readings should be checked when the coils/plug caps are cold I.E. 68 degrees F

You should also check the White Yellow connectors, and the TCI connectors for corrosion, clean as necessary, use dielectric grease on all connectors

[FIZR]

Thanks for the reply's! I will check them out before buying, thanks.

[yamaha_george]

Thanks for the reply's! I will check them out before buying, thanks.

Fizr,
it is always cheaper to ask a question, than buying on a hunch.

[FIZR]

Ok, with the carbs "rebuilt", I found three small o-rings laying in the bottom of my spray bucket? Where do these go on the carbs? They are maybe 4-5mm in diameter.

[thatkid]

they go here and you should have 4

[FIZR]

I've been looking at the schematic and it says there's o-rings under the main jet? Could it be these? Just want to make sure before they come apart again. Thank you!

[thatkid]

I've recently serviced a set of carbs, it did look like there was/could be o-rings under the main Jet, I didn't try getting them out. What schematic were you looking at?

also the mixture screws have a metal washer & rubber o-ring.

EDIT: The mixture screw comes out, then the spring, metal washer, o-ring. in that order.

[FIZR]

Ok, it was the o-ring's by the diaphragm assemblies. I always use the Babbitt's online oem parts diagrams. Thanks again for your reply's!

Carbs done.
Tank cleaned.
Fuel filter turned around(was in backwards).
Fluids drained.

[yamaha_george]

I always use the Babbitt's online oem parts diagrams. !


Fuel filter turned around(was in backwards).

Fizr,
Babbitts? not one i am familiar with, URL?

As for turning the filter backward for use NOT an idea.

Good filters are made to operate in one direction ie on one side they have a bigger space to catch the crud, if you turn it round ,even "cleaned" or new you are reducing the working life(ie reducing the amount of room for crud )of the filter & possibly pumping very tiny bits of stuff into your carbs again.

If you love cleaning carbs fine, there are a lot of guys here who would use your services .

Pop down to the store and buy a fresh one.

[FIZR]

http://www.babbittsonline.com They have schematic's for most major brand bikes.

It's a clear filter that looks clean. Either way I'm sure it will work alot better installed in the correct position.

[thatkid]

No offence, You really should take heed of the advice given Y-G is not a weekend mechanic, he is a Certified Yamaha Engineer.

after the bike had sat for who knows how long?

Any thoughts?

that filter (which is measured in microns) will be full of crap, since it was fitted the wrong way round (which you corrected), that crap is now in your newly cleaned carbs.

[yamaha_george]

http://www.babbittsonline.com They have schematics for most major brand bikes.

It's a clear filter that looks clean. Either way I'm sure it will work a lot better installed in the correct position.

Thank you for that link I will put that in the WIKI,

Link now in the WIKI along with a company that sells Japanese loom repair kits

[FIZR]

http://www.babbittsonline.com They have schematics for most major brand bikes.

It's a clear filter that looks clean. Either way I'm sure it will work a lot better installed in the correct position.

Thank you for that link I will put that in the WIKI,

Link now in the WIKI along with a company that sells Japanese loom repair kits

Thanks for the help George. Now to find a VR in good shape.