What's the deal?

[ostringer]

Newbie here,
’07 VN1600 Classic.
Had this happen to me a few times now over the last 6 months & I’m not sure why exactly:
Downshifting from 4th to 2nd & sometimes the engine will just die (clutch in & no throttle).
Normally I let off on the clutch and let the engine slow me down, but sometimes I don’t have the opportunity.
I find myself having to keep giving it a little gas (roll a hair, let off, roll a hair, let off…) just to insure it doesn’t die.
Idles great other than this at 950 – never dies while stopped.
Bought it serviced (new battery, plugs) – 12k miles.
This can’t be normal? (not good to have the engine die in traffic slowing down for a quick turn while downshifting).

Again, I’m learning & I may not be handling the bike correctly.

[redjay]

Have you tried cleaning the throttle body with a toothbrush and carb cleaner ?

[ostringer]

Nope. Add an oz of Lucas gas treatment about every other tank tho (previous owner did as well).

[redjay]

Try it.

[ostringer]

I'm no mechanic. I'm pretty sure the throttle body's never been removed. Looks like a lot of parts connected - could try if it will fix what sounds like a common issue. Is there some sort of written step-by-step procedure somewhere I can look at?

[ldhthept]

Just have to take off the dog bowl right side, throttle bodies right there. Twist throttle to open the butterfly valves. Spray Seafoam or throttle body cleaner of choice and clean butterflies both sides especially the edges as well as the throat of the bodies that you can see. Should be a write up on here, do a search. Piece of cake makes a big difference.

[ostringer]

So, the reason the bike dies occasionally downshifting with clutch in is "carbon build-up on the butterflies in the throttle body"? (Did the "how to clean throttle body" search you suggested.) Doesn't look like I have to remove the throttle body just to clean. What causes the build-up & is there a way to keep this from happening in future?

[redjay]

It is one thing for you to try to see if it cures your problem.

There is no way to stop the carbon build up.

[ostringer]

Thanks for the help! I'll do it.
https://gadgetsfixitpage.com/article...-body-cleaning

[andyvh1959]

Definitely take the time to clean the butterfly plates with denatured alcohol and long swabs. Open the throttle full, then reach in with swabs soaked in alcohol and completely wipe down both sides of the throttle plates, and bores where the throttle plates contact the bores.

My BMW R1100RS used to stall like yours, often sitting at idle in traffic, and suddenly dead. It would start right back up. Turns out the throttle plates build up sticky oil/carbon, and when the throttle plates close the buildup forms a seal that starves the air into the engine. After I cleaned the throttle plates it never happened again.

[ostringer]

Originally Posted by andyvh1959

Definitely take the time to clean the butterfly plates with denatured alcohol and long swabs. Open the throttle full, then reach in with swabs soaked in alcohol and completely wipe down both sides of the throttle plates, and bores where the throttle plates contact the bores.

My BMW R1100RS used to stall like yours, often sitting at idle in traffic, and suddenly dead. It would start right back up. Turns out the throttle plates build up sticky oil/carbon, and when the throttle plates close the buildup forms a seal that starves the air into the engine. After I cleaned the throttle plates it never happened again.

Thank you. Probably hasn't ever been done on this bike. Will do as you say. Suggestions as to where they might have the long swabs you mention?

[redjay]

Use an old toothbrush

[ostringer]

Originally Posted by redjay

Use an old toothbrush

OK (or my wife's - clean it good before I put it back - I won't tell if you don't)

[ostringer]

Went to O'Reilly and picked up their can of automotive swabs and some throttle body cleaner. Got an old toothbrush (not my wifes). Tied the throttle open and went to work with the toothbrush first. I didn't spray directly into the throttle body but filled the bottom of a glass jar to dip the toothbrush followed by the swabs. Before & after pics (swabs shown are from one bore only). BIG difference how it starts and idles! Obviously it was the first time this has been done. Thanks for your help fellas!

[miltonsain]

as you have just discovered, the members of this forum are the best, they have helped me work out the little bugs on my 2000 1500fi nomad