ADVrider

Go Back   ADVrider > Bikes > Old's Cool
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-04-2011, 05:10 PM   #1
bikecat OP
Beastly Adventurer
 
bikecat's Avatar
 
Joined: Jan 2006
Location: Tropical Far East
Oddometer: 1,078
Fuel in cylinder? She's ain't the same anymore

Hiya,

I think I had messed up my R100R when I was taking a look at my Bings. Failed to set the right Bing's main jet jet properly and got fuel dumped into the carb. Rectified that but may have screwed the fuel prep system?

Bike now runs rough at lower (1-2.5k) rpms with popping on deceleration. I am told that this is as a result of fuel being dumped into the cylinder, and it will take time to burn off. It's weird but the now bike rattles at low revs, especially just before the clutch's bitting point hit, something that I did not get previously. Once I hit past the biting point it purrs. Had taken the bike for a say 40 km ride and problem persists. TwinMax check is good, balances at 1k to 3k.

Anything else that I can do?

Cheers

bikecat is offline   Reply With Quote
Old 09-04-2011, 05:47 PM   #2
Stagehand
+/- V TDSPP
 
Stagehand's Avatar
 
Joined: Oct 2004
Location: Shawangunks
Oddometer: 25,073
You want fuel int he carb and cylinders I thought popping was lean and/or an air leak. And the rough running is probably just a case of your carbs now being unsynched... sorry, dont mean to denigrate your twinmaxxing. How do you fail to set a main jet properly? It just screws in till it stops unless you try to clean it with a wire.

Make sure the float heights are correct, the o-rings around the jets and air screw are not ripped or buggered, and tighten down the clamps again when the thing gets hot. And I would just make sure the idle mix is correct. Basically just do everything again until its right.
__________________
Unintentional psychokinesis.
Stagehand is offline   Reply With Quote
Old 09-04-2011, 06:06 PM   #3
OldPete
Be aware
 
OldPete's Avatar
 
Joined: Oct 2007
Location: Los Alamitos, CA
Oddometer: 3,766
How much fuel in the cylinder?
Enough to create a hydrostatic lock? If so, a connecting rod "could" be bent very slightly.

At anytime did the starter kind of lock up and its button had to be tapped several times? If so you have a real issue.
OldPete is online now   Reply With Quote
Old 09-04-2011, 06:11 PM   #4
Stagehand
+/- V TDSPP
 
Stagehand's Avatar
 
Joined: Oct 2004
Location: Shawangunks
Oddometer: 25,073
Quote:
Originally Posted by OldPete View Post
How much fuel in the cylinder?
Enough to create a hydrostatic lock? If so, a connecting rod "could" be bent very slightly.

At anytime did the starter kind of lock up and its button had to be tapped several times? If so you have a real issue.
I call hyperinflationism. But you had better have the crank replated just to be sure
__________________
Unintentional psychokinesis.
Stagehand is offline   Reply With Quote
Old 09-04-2011, 06:12 PM   #5
caponerd
Kickstart Enthusiast
 
caponerd's Avatar
 
Joined: Jul 2005
Location: Halfway between Munich and Redditch.
Oddometer: 1,976
I'd like to know what you mean by "set the main jet".

There's nothing to set in the main jet, you take it out and put in a bigger or smaller one, and besides, main jet size is nearly irrelevant to anything except full-throttle operation.
caponerd is offline   Reply With Quote
Old 09-04-2011, 06:36 PM   #6
JamesOn2Wheels
Banned
 
JamesOn2Wheels's Avatar
 
Joined: Apr 2008
Location: dammit..back in the states
Oddometer: 422
sounds like it's running lean

which would cause spark knock under 3000 rpm's - I've had exactly that symptom a few times - over 3000 it runs fine.....

Maybe that carb isn't giving fuel right, like stagehand says check the float level...but remember you've dicked with it and now it could be a combination of events

check your idle mix screw...maybe richen it up a little

but pinking, pinging, detonation whatever you call it is either too lean mix, too far advanced, or combination of the two....usually

James
JamesOn2Wheels is offline   Reply With Quote
Old 09-04-2011, 08:32 PM   #7
Xcuvator
Justa Venturer
 
Xcuvator's Avatar
 
Joined: Jul 2007
Location: Skolls Or
Oddometer: 1,352
I suspect he is referring to the float valve as the main jet and setting it right would be setting the float height, Who knows?.
__________________
___________________________________________

So much riding-so little time
Xcuvator is offline   Reply With Quote
Old 09-04-2011, 11:49 PM   #8
bikecat OP
Beastly Adventurer
 
bikecat's Avatar
 
Joined: Jan 2006
Location: Tropical Far East
Oddometer: 1,078
I must apologise. It's the float needle that was not placed properly, then cause the floats to be jammed and I got a deluge of fuel. Case of rushing to do stuff when I should have taken my time.

Perhaps the float height had been altered somewhat, I guess I will start from scratch i.e.

1. valve clearance (might as well)
2. adjust flat height (1/2 inch from top edge of bowl)
3. stock idle / mixture screw settings
4. Long ride to warm up (20 mins / 10 miles)
5. Sync carbs?

Anything I missed out?
bikecat is offline   Reply With Quote
Old 09-05-2011, 07:06 AM   #9
Stagehand
+/- V TDSPP
 
Stagehand's Avatar
 
Joined: Oct 2004
Location: Shawangunks
Oddometer: 25,073
An easier way (for me) to adjust float height is adjust it such that the seam on the floats is parallel to the carb body just at the exact place where the float needle begins to actuate. But otherwise yes, you got it.
__________________
Unintentional psychokinesis.
Stagehand is offline   Reply With Quote
Old 09-05-2011, 07:22 AM   #10
Wirespokes
Beemerholics Anonymous
 
Wirespokes's Avatar
 
Joined: Jul 2002
Location: Jackson's Bottom Oregon
Oddometer: 7,796
setting float level

To say it another way - with the carb mounted to the bike and float bowl off, hold the float up against the needle, turn on the fuel, then slowly lower it till the fuel flows, then slowly move it up till the fuel stops flowing. At that point the seam on the float should be parallel to the bottom of the carb/bowl mating surface. Adjust the tang to make that happen.
__________________
Wanted: Dead, smashed, crashed or trashed gauges
BMW GAUGE REPAIRS - TACH*SPEEDO*CLOCK*VOLT METER *PODs & LIGHT BOARD*
Wirespokes is offline   Reply With Quote
Old 09-05-2011, 07:44 AM   #11
Stagehand
+/- V TDSPP
 
Stagehand's Avatar
 
Joined: Oct 2004
Location: Shawangunks
Oddometer: 25,073
thanks thats much clearer
__________________
Unintentional psychokinesis.
Stagehand is offline   Reply With Quote
Old 09-05-2011, 08:09 AM   #12
Wirespokes
Beemerholics Anonymous
 
Wirespokes's Avatar
 
Joined: Jul 2002
Location: Jackson's Bottom Oregon
Oddometer: 7,796
Welcome! You were clear as well, it just seemed to need expanding a little for a noobie.
__________________
Wanted: Dead, smashed, crashed or trashed gauges
BMW GAUGE REPAIRS - TACH*SPEEDO*CLOCK*VOLT METER *PODs & LIGHT BOARD*
Wirespokes is offline   Reply With Quote
Old 09-05-2011, 05:09 PM   #13
bikecat OP
Beastly Adventurer
 
bikecat's Avatar
 
Joined: Jan 2006
Location: Tropical Far East
Oddometer: 1,078
Have narrowed down the symptoms.

Runs rough, almost reluctant at 1,000 to 2,700 rpms or so, then fuel / power comes in very well. Like I've said, purrs thereon. Have checked float height, cables and also made sure that the cables are smoothly laid out along the chasis. Popping, when it happens, is usually around the 2,500 rpm zone, quite mild but clearly audible.

Points to idle jets, yes?

Thanks for the viewpoints.
bikecat is offline   Reply With Quote
Old 09-05-2011, 05:24 PM   #14
Wirespokes
Beemerholics Anonymous
 
Wirespokes's Avatar
 
Joined: Jul 2002
Location: Jackson's Bottom Oregon
Oddometer: 7,796
Quote:
Originally Posted by bikecat View Post
Points to idle jets, yes?
That'd be my guess. Look very close at the orings - they easily get sliced on the sharp edge of the jet on installation. I'll take a small rat tail file and dull that edge a little to prevent that happening. Anyway, the oring can get sliced, but the cut will hide from view. You've got to lift it away a little to see the damage.

And smear a very light coat of grease on the oring when installing - wipe off any excess so it's only shiny, with no grease visible.
__________________
Wanted: Dead, smashed, crashed or trashed gauges
BMW GAUGE REPAIRS - TACH*SPEEDO*CLOCK*VOLT METER *PODs & LIGHT BOARD*
Wirespokes is offline   Reply With Quote
Old 09-07-2011, 06:24 PM   #15
bikecat OP
Beastly Adventurer
 
bikecat's Avatar
 
Joined: Jan 2006
Location: Tropical Far East
Oddometer: 1,078
Hiya,

It was the idle/pilot jet, cleaned it out with a strand of wire and compressed air. Also checked timing, valve clearance and she's nearly back to normal, pulls well at all ranges. Nearly cos' there's still mild popping on deceleration even though repeated checks with TwinMax show balance at 1,000 and 3,000 rpms.

I can live with the popping but is it indicative of something detrimental?
bikecat is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 05:29 AM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014