Throttle body balancing

Bikerhoss · Post by **Bikerhoss** » Mon Jun 17, 2013 9:07 am

Older thread I appreciate, but resurrecting just to ask a silly question.....

I checked my valve clearances (exhausts were a bit tight, inlets a bit slack), and set the end floats, but the bike seems to hesitate between 4-5000rpm? Just needing a balance?
Ta, Hoss.

conkerman · Post by **conkerman** » Mon Jun 17, 2013 10:24 am

Most probably as by adjusting clearances you are changing the amount of air getting into the cylinder.

I did mine yesterday with a carbtune as they were well out and the idle speed was too high. Just did a quick and dirty adjustment, as I'll be servicing the bike fully and will need to re do. Took me longer to free off all the adjuster nuts on the cables than to do the balancing.

Bikerhoss · Post by **Bikerhoss** » Wed Jun 19, 2013 6:39 am

Right, I played about with the brass idle screws last night (only 1.5 turns each out from fully in) and the throttle cables seem to be opening/closing at the same time/tension, but.....

the bike seems to almost run out of fuel at 4500rpm, and really struggles to rev beyond that (but only under load), which is damn frustrating as I tend to hover around 5000rpm most of the time,

I checked I hadn't crimped any fuel lines when I had the tank up, and swapped out the plugs just in case,

Am I mistaking poor balance for an ignition failure? Coils on the way out?

Dai wiskers · Post by **Dai wiskers** » Wed Jun 19, 2013 7:16 am

Fuel filter?

Could be ignition side of things but check that fuel filter first

conkerman · Post by **conkerman** » Wed Jun 19, 2013 4:20 pm

My bike is a PITA to get some slack on the left throttle body.

Will be having another pop at it.

On a sort of related question, what difference does an adjustment to the TPS make??

Steptoe · Post by **Steptoe** » Wed Jun 19, 2013 7:02 pm

Bikerhoss wrote:Right, I played about with the brass idle screws last night (only 1.5 turns each out from fully in) and the throttle cables seem to be opening/closing at the same time/tension, but.....

the bike seems to almost run out of fuel at 4500rpm, and really struggles to rev beyond that (but only under load), which is damn frustrating as I tend to hover around 5000rpm most of the time,

I checked I hadn't crimped any fuel lines when I had the tank up, and swapped out the plugs just in case,

Am I mistaking poor balance for an ignition failure? Coils on the way out?

is your bike a twin spark model - if so check the main coil sticks. They're notorious for failing and give the type of symptoms you have.

Bikerhoss · Post by **Bikerhoss** » Wed Jun 19, 2013 8:10 pm

Single spark Steptoe, Ta.

Well, tank off earlier, and jeez is that pump/filter assembly a bitch to take out the tank or what

Anyways, disconnected and cleaned out the filter, Wee bit of black sludge, but it blew through ok. Cross fingers runs better tomorrow morning.

Dai wiskers · Post by **Dai wiskers** » Wed Jun 19, 2013 10:13 pm

If no better remove the plastic covers on the rocker covers (can't remember the propper name for them ) you have guessed it Dai's been self medicating again

Start the bike up in a darkened garage or wait till it gets dark (now would be a good time ) and check for any stray sparks from the high tension circuit yup looking up under the tanks a bit awkward
A temp bodge for stray sparks is damp start available from most motor factors just soak the area and let fully dry before starting the bike

Mine used to miss in the wet coming home in the wet one night the missing got better for no apparent reason looking over the bike the next day i found i had lost one of the plastic covers on the rocker cover when i took the other one off a surprising amount of water ran out of now my bike runs fine in the wet with no covers over the plugs (got fed up of saying covers on the rocker covers )

Don't give up on the simple cheap fixes okay the fuel filters a bitch to get to but it's a job well done

Hope this makes sense Dai

Bikerhoss · Post by **Bikerhoss** » Thu Jun 20, 2013 6:50 am

made it two miles from the house this morning, and had to turn and limp home,
Bike ran like a pig, not passed 3000rpm this time, and by time I got home I could smell burning

and on looking in the exhaust, the pipes were glowing red hot!!
Sounds like I'm missing the ignition spark, and fuel is burning off in the exhaust, Am I right

New HT's needed

Dai wiskers · Post by **Dai wiskers** » Thu Jun 20, 2013 8:23 am

Calling Steptoe

Glowing pipes? Lack of power weak mixture or timing out just thinking out loud hall sensor wiring?

Steptoe's the man hopefully he will be reading try a pm just in case

ned1 · Post by **ned1** » Thu Jun 20, 2013 10:28 am

Single or twin spark.................

Twin spark has a coil pack on the main plug so I would think it would just run a bit lumpy.
Just thinking out loud.

Ned

Merecat · Post by **Merecat** » Thu Jun 20, 2013 10:42 am

Bikerhoss wrote:Older thread I appreciate, but resurrecting just to ask a silly question.....

I checked my valve clearances (exhausts were a bit tight, inlets a bit slack), and set the end floats, but the bike seems to hesitate between 4-5000rpm? Just needing a balance?
Ta, Hoss.

I would recheck.?
What was it running like before?

Bikerhoss · Post by **Bikerhoss** » Thu Jun 20, 2013 10:48 am

Ned -

Bikerhoss wrote:Single spark Steptoe, Ta.

Was staring to run a bit 'coughy' about 5Krpm before doing the clearances, and valves were noisy, but nowhere near as rough as now.

Bikerhoss · Post by **Bikerhoss** » Fri Jun 21, 2013 6:27 am

Ok, valves rechecked last night, Spot on still. Plugs out and checked for spark on tick over, fine too. Couldn't see any 'stray' sparking either.
Holding the engine between 3-5K, the bikes splutters and doesn't want to rev, Fair smell of unburnt fuel from the pipes,
Ignition under load problem

Dai wiskers · Post by **Dai wiskers** » Fri Jun 21, 2013 7:21 am

http://www.gsshop.biz/

The best advice i can give you is give Neil (Steptoe ) a call

Those of you in the south east if your bike needs a service or other work there really is only one place to go