MikesXS Electronic Ignition Kit

[rbirkey]

OK, I'm looking on the Niche site, and at first couldn't figure out what I need. But after some additional searching, I think I am looking for these in various sizes... correct?

Mikuni VM22/210 Pilot Jets
Mikuni N100.604 Large Round Main Jets

 

[5twins]

You found the correct pilots but for mains, your carbs use the small round main, the N102/221 type, not the large round type .....

 

[Jim]

And if you haven't already done so, 5t and grzld1 wrote an excellent carb guide... you should give it a read.

 

[MaxPete]

On tires - I just installed a set of Michelin Pilot Activs (no “e”) and they really ride very nicely.

 

[rbirkey]

Thank you all! I have ordered the Dunlop K50's for my friend's Yamaha because he likes how they look. I have ordered a range of jets, and found a few more items on Niche Cycle! Slowly, step-by-step I am learning and we will get this beautiful XS650D running, safe, licensed and back on the road!

 

[650trader]

Gawd: K70's are like hockey pucks. I had them new on my XS1b and after I switched to Pirelli Phantoms
I had a new machine - Suddenly it would stop, go and handle. The old K70's were passed from friend to friend
whenever someone needed a tire but had no cash. Touch the rear brake and they would break loose in an instant
but the tires lasted forever .

 

[MaxPete]

but the tires lasted forever .

On tires like that, we used to say: “the only reason they paint them black is to stop them from rusting”.

 

[rbirkey]

I am at the final stage of fine tuning the carbs for this setup. 5twins suggested 27.5 pilots, 132.5 mains and the stock needle leaned one step as a place to start because he has a similar setup to this 1977 xs650d. In reading the Carb Guide I understand that I need to start with the mains. I have the 27.5 pilots installed, with the stock needles as well. I tried the 132.5 main size but the engine cuts out at around 3000 rpm. So I went up to size 134, and it still acts the same. Does this suggest that I need to go still larger? I've ordered the 135, 137.5, 140 and 145 in case I do.

It starts and idles ok, with an exhaust pop on the right side exhaust every few seconds. I think I may have air entering the slipon's at the junction with the header. There is no clamp at that point on this bike.

The timing advance seems to be working. At idle the mark is dancing around the Fire mark. As the rpm's increase to 2500 to 3000, the mark advances toward to left end "Advance" mark on the scale.

Thoughts and suggestions?

 

[member28833]

engine cuts out at around 3000 rpm.

Does it stumble and then recover ?
If so I’d play with the needle height a little just because that is relatively easy. As you get very close, you can even shim the needles about a half slot by using a thin washer. That actually worked nicely once for me .(thx 5twins)
Also are you able to change main jets with the carbs in place through the bowl drain ?

 

[rbirkey]

Machine... no it never recovers... I can't get the engine past 3000 rpm. Right now I have the needles set on the 4th slot down from the top end... there being 5 slots total. I assumed this was the suggested "lean" one step. I had tried the 5th slot last night and it didn't seem to improve things.

 

[member28833]

no it never recovers... I can't get the engine past 3000 rpm.

Warm engine ? How did it run cold while on choke ?
Too bad it will not run above 3,000 for more clues. Does flipping on the choke affect it ?
Symptoms seem carbureation rather than electrical to me.
Remove air filters and try manually lifting the slides while running for clues? Good luck -R

 

[gggGary]

At idle the mark is dancing around the Fire mark. As the rpm's increase to 2500 to 3000, the mark advances toward to left end "Advance" mark on the scale.

Thoughts and suggestions?

Mark shouldn't be "dancing", cam chain set properly?

watch the mark as you rev it to 4000 does't stay lit or go out?
Is this mechanical or electronic advance?

 

[rbirkey]

This is the MikesXS ultimate kit with electronic advance. I just went over everything again, cam chain tension, timing, jets, needles, sync... everything seemed ok, and I don't know what I did but suddenly it rev's all the way up now! I am now adjusting the needles to get rid of some sputtering and power loss past 4000 rpm! I think we are in business!

 

[gggGary]

Too bad you are so far away...
Pic of the bike?

 

[rbirkey]

OK Friends... the 1977 Yamaha XS650D is running! I am in the final steps of tuning the carbs. I have them currently synced and set up like 5twins recommended: 132.5 mains, 27.5 pilots, stock needles set in the 4th position down from the top end, air mix screws out 2 turns. It runs but bogs down at around 4,000 RPM. Here is a video clip.

https://photos.app.goo.gl/z99xNpyPFjYfEJMo6

I've tried going to 136 mains and 130 mains, with the stock needles in the 3rd and 4th positions... with no noticeable improvement or success. I also tried the Y55-R needles (2.995 dia.) which did not work.

Any suggestions on the air mix screws, needle adjustments.... next steps?

Thanks!

 

[member28833]

OK Friends... the 1977 Yamaha XS650D is running! I am in the final steps of tuning the carbs. I have them currently synced and set up like 5twins recommended: 132.5 mains, 27.5 pilots, stock needles set in the 4th position down from the top end, air mix screws out 2 turns. It runs but bogs down at around 4,000 RPM. Here is a video clip.

Fun video. Not seeing the mufflers. That video sounds like open exhaust ?
The prescribed jetting may not be working well if the exhaust is still open.
The popping and back firing at high rpm ( over 4K) seems like ignition timing to my ear ..

 

[rbirkey]

As far as I can tell, these are the mufflers with stock headers...

http://www.nichecycle.com/ncs/categ...50-mufflers-taper-tip-by-mac-performance.html

My problem with timing is that the mark on the stator jumps around between the TDC and FIRE marks. Here's what it looks like with my timing light set at "0" advance. It displays the same on either spark plug wire. When I open the throttle, the timing mark seems to stabilize and advance toward the "Advance" mark.

Here is my entire timing setup...

 

[TwoManyXS1Bs]

Just for fun, temporarily reroute the left spark plug wire forward of the head, getting it away from and non-parallel with the ignition wiring...

 

[member28833]

OK Friends... the 1977 Yamaha XS650D is running! I am in the final steps of tuning the carbs.

Na, the final steps are while you test ride ! Diagnosing the main jets and needle choices needs to be further determined while test riding . Engine under load.
On the bike bench you can focus on the idling and sync and get the good feel for the transition off of the pilots but going for 4,000 rpm in neutral is not the whole representation of how the CV carbs are going to work.
This is a fun thread to watch though you’ve made modifications I would not choose.
And I hope you are close to a good running bike !
-R

 

[rbirkey]

So, based on TwoManyXS1Bs's comment, I did reroute the spark plug wires forward and away from the MikesXS kit ignition wires. This stabilized the timing marks and I've been able to improve the timing to pretty much dead on. I've synced the carbs again and adjusted the idle and air screws for a really nice smooth idle. It's idling and running the best it has so far, but when riding it still stumbles around 4000 rpm but not as bad as earlier today. My comments in earlier posts today were under riding load as well.

So I'm thinking I may not have the needles on the best slot. Instead of 4 slots from the top, I am thinking to try 2 as I've tried slots 3 and 4 already.