adjusting throttle bodies and air fuel mixture HP2s

Jeff Williams · 02-28-2009, 02:39 PM

hi all,
well i went for my 6000 mile service,(at 7000 miles), and very thing went well except that hollywood bmw can't seem to make the bike run like it should. it pops when warm at deceleration, and hesitates when given moderiate or full throttle under 4000. and the bike vibrates rough at idle. they say that they tuned it to specs and didn't put in the update because of the bike not running right

after the new map is put in.

questions.
1, can the throttle bodies be adjusted with a meter stick or v-max at home.
2. can the air fuel mixture be adjusted to make the bike run smoother.
jeff

SergioK · 02-28-2009, 04:26 PM

Jeff, who cares about popping on decel?? That's just what this bike does.

IIRC, the TB's are synced at idle using the GT1 and after idle you can use a Twinmax or similar and adjust throttle cables as usual. No idea about fuel mixture.

When you say "vibrates rough at idle", is it sputtering and spewing or just shaking? My bike shakes too - I think it's nervous cause of what I'm about to do to it.

Steve Carlton · 02-28-2009, 04:59 PM

Your bike needs a top-end overhaul, Jeff. I'll offer you a straight-across trade for my sweet-running R1200S. That's today only, buddy.

Jeff Williams · 02-28-2009, 06:04 PM

Quote:

Originally Posted by SergioK

Jeff, who cares about popping on decel?? That's just what this bike does.

IIRC, the TB's are synced at idle using the GT1 and after idle you can use a Twinmax or similar and adjust throttle cables as usual. No idea about fuel mixture.

When you say "vibrates rough at idle", is it sputtering and spewing or just shaking? My bike shakes too - I think it's nervous cause of what I'm about to do to it.

Sergio,
its shaking in a rough manner, like it out of sync.
but the killer,which is could be, is the hesitation when you roll on the throttle. Sometimes it hesitates, then hits very hard which is a recipe for a high side

jeff

Peter Parts · 01:41 AM

Hard to think of anyone who better merits that fine machine than Jeff.

The best I can offer is a little diagnostic suggestion: ride around with dual vacuum gauges. They can provide you with a whole world of "insider" information and far more than a TwinMax (which only reads relative pressure and in unknown and arbitrary units, not absolute pressure in conventional units). A special issue they might illuminate is the butterfly-on-a-wire and what the stepper motors are doing while you are busy driving. Even if all indications are that the breathing is more or less normal and the same on both sides, that reduces or makes less likely a lot of possibilities. I assume the Moditec or whatever reads from some vacuum ports somewhere on the TBs.

Might cost $50 for a pair (be sure to get snubbers and/or raid your office for hemostats!). And some duct tape. Or buy three and return the one most poorly matching the others.

Steve Carlton · 02-28-2009, 06:42 PM

Jeff- do a search under "idle actuator." I'm having a rough idle problem myself, and I think that's going to be the issue.

Guest24 · 07:39 PM

I'll try and talk to the tech that works on Nate's HP2S on Tuesday and see what he says. Nate's #32 bike is pretty much stock except for the Akra exhaust. Jeff the pop on decel is due to the relief valve on the exhaust flap opening I think. Jeff you may very well be lead the flee stateside on mileage.

SergioK · 02-28-2009, 08:16 PM

Quote:

Originally Posted by Jeff Williams

Sergio,
its shaking in a rough manner, like it out of sync.
but the killer,which is could be, is the hesitation when you roll on the throttle. Sometimes it hesitates, then hits very hard which is a recipe for a high side

jeff

I have noticed a very slight 'hesitation' on the bike. I say 'hesitation' but it was more like a slight power dip. It was consistent in that it was always at the same rpm range and gear (IIRC, it was a higher gear/lower speed/elevation too, which may be why this materialized). Either way, I don't think the idle vibration has anything to do with it. Like I said, my bike doesn't really idle too smoothly. The mirrors shake so much you can't really see. It's inconsequential since it runs fine, IMO. As for the hesitation I discovered, it seems like it is just how this engine behaves at that gear/rpm/altitude. It's been a good couple months since I experienced the issue. Do you remember what gear/rpm it was most noticable?

Guest24 · 02-28-2009, 09:22 PM

Too much NOX in the air out there.

Jeff Williams · 02-28-2009, 10:55 PM

Bubba,
please talk to him and find out what can be adjusted w/o a computer in this area.
as for nox.... well pull my finger hehehehe
Sergio just rode home tonight from hollywood, moms not doing well... The bike idles like a ducati and below 4k it sucks, very abrupt. The only thing i can figure is they put it on the computer and adjusted it to smog specs.

Steve Carlton · 03-01-2009, 12:48 AM

Jeff- I'll throw in the luggage and the tank bag...

shreddr · shreddr's Garage

I hate to suggest the obvious, but isn't there a thread about a single throttle body cable not fully seated on one side that was giving some really rough performance?

JonyRR · 03-01-2009, 09:45 AM

Dr. jeffery:

The symptoms you describe remind me of my bike, stock from the showroom floor.
I'll bet there's not a large body of knowledge on how to tune a HP2S specifically.

You know you're gonna have to tune it to get it right.

Rapidbike and dyno time, doc

I'd also wonder about the ethanol content in the fuel.......

NakedRider · 03-01-2009, 09:57 AM

Quote:

Originally Posted by shreddr

I hate to suggest the obvious, but isn't there a thread about a single throttle body cable not fully seated on one side that was giving some really rough performance?

I've had that happen but it will raise the idle for obvious reasons.

Steve Carlton · 03-01-2009, 10:05 AM

Don't forget- my bike's black, Jeff.

Or Plan B: ship the bike to SJBMW. I will work very very hard with Chris to make sure that puppy is running sweeter than a cheerleader's 18th birthday.

Guest24 · 03-01-2009, 10:20 AM

Quote:

Originally Posted by Jeff Williams

Bubba,
please talk to him and find out what can be adjusted w/o a computer in this area.
as for nox.... well pull my finger hehehehe
Sergio just rode home tonight from hollywood, moms not doing well... The bike idles like a ducati and below 4k it sucks, very abrupt. The only thing i can figure is they put it on the computer and adjusted it to smog specs.

I'll make it a priority Jeff.

Steve Carlton · 03-01-2009, 10:46 AM

Somebody call a tow truck for Jeff.

Jeff Williams · 03-01-2009, 11:51 AM

Quote:

Originally Posted by JonyRR

Dr. Jeffery:

The symptoms you describe remind me of my bike, stock from the showroom floor.
I'll bet there's not a large body of knowledge on how to tune a HP2S specifically.

You know you're gonna have to tune it to get it right.

Rapidbike and dyno time, doc

I'd also wonder about the ethanol content in the fuel.......

Jony,
you nailed it...
Guys remember when your bike was new,(the hp2 guy especially), it sputtered, ran rough and wasn't consistent.
Well thats how it feels only the bike is broken in and hasn't felt like that for 6000 miles.

I'm going to a fuel management system within the month but I would like the bike to be at least a proper base line rather than this shyt.

Stevie,
you can ride my bike anytime but you can't have it unless you throw in a baby's arm holding an apple or a heard of Winnebago's,(their giving them away

)
Jeff

SergioK · 03-01-2009, 12:04 PM

I just clicked over the 3k mark and I haven't noticed this change you describe. Something is wrong with your bike. I strongly suggest you take up Steve's offer before he rescinds it.

Guest24 · 03-01-2009, 12:10 PM

I'm remembering all the child abuse you two posted during the early mileage days of those two west coast twins. Could this be teenaged rebellion?