Its Time to Start Again

[Adamc]

So I was digging through boxes and found an m-unit from what research I've done it seems to be a replacement for the fuse box system, and really expensive, is this something I should go ahead a use instead and how would this change the current wiring setup?

Yep, well worth the effort to install. I did it to my bike and built the whole loom from scratch. Solid state reliability, with fail safety built in. Plenty of info on how too on YouTube and Moto-Gadget website. Also help here with JP & me if needed.

 

[Dakon]

I would suggest then getting an M-button and momentary handlebar switches. It's optional, but make life easier and look "slicker"

Our friends over at Dime City (Tampa) have them
https://www.dimecitycycles.com/m-button.html
https://www.dimecitycycles.com/moto...-2-black-push-buttons-for-7-8-handlebars.html
https://www.dimecitycycles.com/moto...ainless-push-buttons-for-7-8a-handlebars.html

Well it looks like I already have the M-button so that's that, I'll go ahead and pick up some switches if that's all im missing

 

[Dakon]

Before diving into the deep end with the M unit, wire up a SIMPLE harness, ignition only is fine and find out if you have a WORKING ignition. Those mike's iggys have a bit of a reputation. Ditto Pamcos on capacitor only (no battery) electric systems.

The backing plate for the iggy doesn't appear to be bolted down, (timed).
Blue circles

Sounds like an excellent place to start, what do I really need to focus on to get the ignition tested? The bike is more or less in pieces so do I need to sort out the carbs/fueling before I proceed?

 

[jpdevol]

Sounds like an excellent place to start, what do I really need to focus on to get the ignition tested?

I think Gary is suggesting a temporary hook-up to see if it makes sparks. So long as the motor will spin, you can temp. hook-up the ignition and coil to a battery that is grounded to the engine block. Make sure to include the 7.5A fuse ahead of the ignition.........
Up to you, but a way to "get your feet wet"

EDIT: OOhhh, make sure to ground everything (battery, ignition module), including the spark plugs (while out of motor) to the engine

 

[Dakon]

On another note, I have two sets of carbs, one that seems original to the bike and a set of new ones I picked up from a Facebook marketplace estate sale that I paid like $100 for a few years back, there both labeled Mikuni and I was told they would both work with the xs650, but im not really sure which I should stick with, there's not really any sort of model numbers so Im not really sure where to start, figured I should probably go with what seems like the original parts unless its more work

 

[Jim]

First pic, the VM's .... IF those are Mikuni and not Chinese knockoffs, you'll need to know what size they are before you'll know if you can use 'em.

 

[jpdevol]

Pros & Cons each way and each may work. Both will likely need fiddling for sea level, the CV carbs slightly more complicated. CV's appear to be stock '78-'79 BS38, Niche may be these:
http://www.nichecycle.com/ncs/mikuni/carb-kits/yamaha/mikuni-34mm-yamaha-xs650-carburetor-set.html

 

[Dakon]

First pic, the VM's .... IF those are Mikuni and not Chinese knockoffs, you'll need to know what size they are before you'll know if you can use 'em.

In the box, when I got them probably 17ish months ago there was a receipt from Cognito Moto says Mikuni vm34, not sure where that paper is now but it was definitely Cognito Moto, I had been a big fan of theirs so I instantly recognized the name

looks like these
https://cognitomoto.com/products/mikuni-vm34-carb-kit-for-yamaha-xs650?variant=7834332161

 

[jpdevol]

In the box, when I got them probably 17ish months ago there was a receipt from Cognito Moto says Mikuni vm34, not sure where that paper is now but it was definitely Cognito Moto, I had been a big fan of theirs so I instantly recognized the name

looks like these
https://cognitomoto.com/products/mikuni-vm34-carb-kit-for-yamaha-xs650?variant=7834332161

OK, but the pic shows Niche Cycle and they list the pre-jetted specs (meybe a resale thing?)

 

[Dakon]

OK, but the pic shows Niche Cycle and they list the pre-jetted specs (meybe a resale thing?)

I would assume so. perhaps they just add the flanges and filters and call it a day?

 

[Wingedwheel]

One of the things I would check is compression. I know from experience what it’s like putting a bike together only to find it needed more motor work than I thought. There’s always this route also for the harness.
https://www.ebay.com/itm/2749944738...deQRADygs0yVUlnervVK1vwkvxA=|tkp:BFBMpoqoh_Jh

 

[Dakon]

Alright, I've got a bunch parts in from all over including the momentary switches, new handlebars that I can run wires through and a bunch of other crap, I'm using the revival cycle wiring diagram, between a new tank, the mikuni vm34 carbs, new petcocks, new lines, new battery, new solenoid, and doing my best to get the questionable mikesxs ignition system put together, I should have everything to attempt to start it up this weekend or next, I'm in the middle of moving stuff from my old place but I'm hoping that it all comes together so I can start focusing getting it to a stage that I can start riding it. Wish me luck!