Valve adjustment

[demito]

Hi,

after a 10000 km service my bike was running somewhat heavier than before, although valve adjustment and TB synch was done by the dealership.
Bought myself a carbtune and used Migsels manual to find out a slight difference between the two TB's, not even 1/4th turn of the TB screw thingy. Bike is running a bit better now (noticable), but stil not as before.

What I noticed though was that when revving up the two TB's were not in synch. At constant revs they were (2,5 K). Left TB dancing up and down a little more then the right one (or was it the other way around, can't remember )

Thinking of rechecking the valves and do some adjustments there (as described in the manual on this forum). Could a wrongly adjusted valve explain the difference in vacuum level when revving up? Is this worth investigating. Any experiences with the valve adjustment procedure as described in http://www.ukgser.com/forums/download/OVADv2.1.pdf ? Piece of cake?

Tnx for the feedback.

Cheers

Demito

 

[Gecko]

Yes - very good experience with the OVAD guide. It really is the dummies guide and has some humour in it too. First time it takes a while and you should follow the guide step by step all the way - second time you will know which bits you can skip with confidence.

 

[Tsiklonaut]

Youp, i readed the same manual too + Haynes i got.

First time is learning=bit harder.

Next times=piece of cake.

Sync the carburateurs after valve adjustment too - they'll very probably need it as mine does.

Cheers, Margus

 

[demito]

torque wrench

Read about estimating the torque. Anyone of you used a torque wrench to do the job or am I too concerned now. I would eventually buy one (8-60 Nm with 'stick on' open bits). Will this make any difference?

Cheers

Demito

 

[Slimie]

A torque wrench is ALWAYS a good idea, especially with so much alloy to strip threads from!

-Simon

 

[Flaps]

I never used a torque wrench to tighten the bolts. I took some of OVAD's advice and tightened up the bolts with only my finger tips on the spanner. To undo them I had to use a spanner and a hammer!

As to the change in pressres: I used the TwinMax differential meter OAVD recommended. When the engine is at tickover the needle is centred (properly adjusted). As the engine revs the needle moves in one direction (shown on the meter's most sensitive setting). I don't know why this is but according to OVAD it's quite normal. As long as the needle returns to the centre position when the throttle is of, everything is okay. At least that is what I did!

I did this for the first time with 28,500 miles on the clock. The engine is a bit smoother, but not as sharp as I hoped. The first 2k of the rev range feels a bit rougher though.

 

[Sergeant Pluck]

As to the change in pressres: I used the TwinMax differential meter OAVD recommended. When the engine is at tickover the needle is centred (properly adjusted). As the engine revs the needle moves in one direction (shown on the meter's most sensitive setting). I don't know why this is but according to OVAD it's quite normal. As long as the needle returns to the centre position when the throttle is of, everything is okay. At least that is what I did!

I don't know anything about OVAD but this sounds like you're only doing the first stage of a 2 stage process.

First stage is to zero the needle at idle using the brass screws - then the second stage is to zero the needle (or as near as poss) at just above idle - say 2000rpm - using the RHS throttle cable adjuster. Stage 2 being the important one.

 

[Flaps]

Sgt Pluck (T.T.F.K.A.P.)

I think you're right. I have just gone back and re-read Oilhead Valve Adjustment for Dummies (OAVD). It appears that I have missed the throttle cable adjustment as I didn't thiink I needed to do it. So that is this Saturday's task!

One question...why the RHS?

Cheers


Flaps

 

[Sergeant Pluck]

Cos the RHS is a slave activated by the main LHS cable which comes from the throttle. So any adjustment to the LHS will affect both sides - and not allow you to adjust them individually.

And a question for you! What is T.T.F.K.A.P.?

Cheers

 

[cookie]

The Twat Formerly Known As Prat?

 

[MikeO]

Cos the RHS is a slave activated by the main LHS cable which comes from the throttle. So any adjustment to the LHS will affect both sides - and not allow you to adjust them individually.

And a question for you! What is T.T.F.K.A.P.?

Cheers

Hmmm.

Not sure about the master/slave bit. The throttle cable runs from the handlebar to a splitter box where both left and right hand side throttle cables emerge. The reason for adjusting the right hand side is that you have to leave *one* cable alone, to match the second one to. Having replaced throttle cables, I'm pretty sure you could achieve the same effect leaving the RHS alone and adjusting the left...

Mike

ps I'm guessing " The Tosser Formerly Known As Prune"...

 

[Sergeant Pluck]

Hmmm.
Not sure about the master/slave bit. The throttle cable runs from the handlebar to a splitter box where both left and right hand side throttle cables emerge. The reason for adjusting the right hand side is that you have to leave *one* cable alone, to match the second one to. Having replaced throttle cables, I'm pretty sure you could achieve the same effect leaving the RHS alone and adjusting the left...

Mike

Could very well be right - I read about the slave thing somewhere, and it could well be wrong.... never actually bothered to look!

 

[(RIP) Bin Ridin]

Early oilheads had a cable which ran over the lh pulley to the rh pulley. Later ones have a splitter box.

 

[MikeO]

Early oilheads had a cable which ran over the lh pulley to the rh pulley. Later ones have a splitter box.

That'll explain it - I was talking about a 2002 Adv...

Mike

 

[Flaps]

Thanks Guys.

Okay, so I can use either side to adjust the throttle bodies. How do I know which side to use and which way to turn the knurled knob?

I used the LHS BBAS to adjust the air flow at tick over.

Flaps.

PS Mike is right

 

[Keith Chapman]

I was under the impression that all adjustments were made on the RHS body.

 

[MikeO]

Thanks Guys.

Okay, so I can use either side to adjust the throttle bodies. How do I know which side to use and which way to turn the knurled knob?

I used the LHS BBAS to adjust the air flow at tick over.

Flaps.

PS Mike is right

What you're doing, effectively, is matching the lengths of the 2 throttle cables. In other words, ensuring that both throttles start opening at exactly the same time. To do this, you're going to lengthen or shorten the right hand cable. Once you've undone the locknut, you can do this easily by hand - use the Twinmax (or whatever you're using to balance the vacuum), to work out which way to turn the adjuster (it'll be trial and error).

Once you've found the right spot, be aware that it's very easy to alter the balance when tightening the lock nut up again - it can drive you round the bend ...

Mike

ps Beware running the engine too long unless you have fans blowing on the pots - my headers glowed cherry red in a surpsisingly short time, even though the oil temp was still just showing 5 bars...

 

[Flaps]

Mike,

Thanks for that.

I had a go last Sunday and it turns out to be very easy. Having set up the Twinmax and checked everything was same from last time, I started to experiment. One very quick adjustment following your advice later, the needle does not move from the centre at all as I throttle up and down. So I went for a ride and the bike is running fine.

Cheers,

Flaps

 

[demito]

synchronization with crashbars

Any tricks there? I have the BMW crashbars and find it very difficult to reach the locknut of the throttle body.
Do you guys take them off when synching the TB's?

Cheers

Demito

 

[cookie]

Re: synchronization with crashbars

Any tricks there? I have the BMW crashbars and find it very difficult to reach the locknut of the throttle body.
Do you guys take them off when synching the TB's?

Cheers

Demito

i think you may be looking at the wrong adjuster. you should leave the one with blue paint on alone & use the cable adjuster & air bleed screws.