air filters jet kits & cans

[midlifekrisis]

Hi everyone
Hope you all had a good summer, can I pick your collective brains?
I purchased an x plate with just 10k on the clock and art cans, it now appears it has some sort of jet kit as the internals are not standard, the only standard bit is the air filter.
it pulls ok up to 6k then holds back pops and farts and doesn't want to play.
The questions are; which is the best air filter k&n, piper or bmc?
How many carb jet kits are there and the pipes are very very noisy.
I suspect the filter is causing the holding back and the sliders aren't lifting, the plan being to try a filter and put some db killers in the cans to save being lynched. next step would be to see if the needle needs lifting.
What do you think?
Dave (midlifekrisis)

[tony.mon]

Cam timing is 180 degrees out.

[midlifekrisis]

Thanks Tony, cam timing 'should' be fine as 38 miles after collecting it the front tensioner spring failed, I was very lucky and the valves did not hit the pistons, some of Aides ccts were fitted and the valve clearances checked and adjusted, so cams have been out. How can it run if 180 degrees out?
Dave

[lloydie]

It runs good when the timing is out 180' right up to 6k then won't pull through .
You need to check the timing .
First set the rear to tdc on the rear cylinder the cams should be pointing up and in on the rear cylinder .
Now rotate the crank 1and 1/4 turns anti clockwise till the ft lines up in the window .
The front cams should be pointing away from each other . If the front ones are not its 180' out and you need to reset the timing .

[lloydie]

They normally get timed up wrong after the ccts have been changed by someone that don't know these bikes or follow the Haynes manual that is wrong

[VTRDark]

Now rotate the crank 1and 1/4 turns anti clockwise till the ft lines up in the window .
The front cams should be pointing away from each other . If the front ones are not its 180' out and you need to reset the timing .

Not quite mate. If only it was that obvious. This is why it gets overlooked as everything will look exactly right and as it should be, including all timing marks.

Thanks Tony, cam timing 'should' be fine as 38 miles after collecting it the front tensioner spring failed, I was very lucky and the valves did not hit the pistons, some of Aides ccts were fitted and the valve clearances checked and adjusted, so cams have been out.

Now here lays the problem. Someone has moved the crank before re-fitting the cams or not set it right to begin with. All it takes is for the crank to be moved to the next RT or FT (depending on which cylinder is being used) misleading someone into thinking the timing is correct. These bikes have an offset timing order between cylinders.

The fix is to set the rear cylinder to TDC (RT at crank) with both rear cams pointing UP and INWARDS (not out like the front) Note the RI and RE on the cam sprockets will align with the top of the head casing on the outside. To fix the 180 out, loosen the cam cap holder bolts or better still remove the cams out the way. Then with a helper holding (feeding) the chain so it does not get caught up around the crank or fall down the cam tunnel. Rotate the engine at the crank anticlockwise one full turn until RT comes around again. Then re-fit the cams as before (as they should be) with the lobes pointing up and in and the RI and RE aligned with the top of the cylinder head and it's done.

Tip for you put the inlet cam in first and pull the chain tough around that one first. Secure down loosely and cable tie the chain on to the sprocket. Then install the exhaust cam. You want the slack on the tensioner side which is then taken up by the can tensioner.

The questions are; which is the best air filter k&n, piper or bmc?
How many carb jet kits are there

Standard filter is best. As for jet kits I can think of about 7 different types off the top of my head. It's not a case of one kit working better than another, it's a case of understanding carbs and how they work and how to adjust your jetting accordingly.

If your slide/s where sticking or not opening you would have the bike run like a pig, coughing and spluttering as if it's fuel starved, way before you hit 6k. In fact the bike would run better at higher speeds/revs.

(:-})

[sirch345]

When the CCT failed, did you follow the guides we have here in "The Workshop Knowledgebase" for setting the valve timing, or use the Haynes workshop manual

Chris.

[VTRDark]

Argh yes off course the Haynes manual boo boo

(:-})

[AMCQ46]

sounds like a classic 180 deg cam timing, and the fact that the bike has just had CCT work done makes this the #1 suspect

[AMCQ46]

I need to sort out a day in the workshop to replace the noisy CCT [with stopper] on Malc's bike, if you need help to re-do the timing we can try and do both together.

its an easy mistake to make if you follow the Haynes Manual [hence everyone asks if you followed the instructions on this site, as they will make sure you don't do it wrong], but it causes no damage, its just the bike cant flow enough air through the airbox when both cylinders are on inlet stroke too close together. it is also fairly easy to fix, but you need to strip it all back down till you can get the cam covers off again

[midlifekrisis]

Hi everyone

Many thanks for all the info, the symtom is 'running out of breath' and the fitting details I used were from the Keiger website, I've only just brought a 'haynes' manual - ripped the cam timing pages out now.
I am having trouble in my brainbox thinking 'how can it be 180 out - it shouldn't run' I then wake up in a cold sweat at 3am.
Thanks for the offer of checking the timing AMCQ, I know its a ball ache stripping but I know there is nothing siezed, stripped or broken, I shall ask Adam (tech who fitted the ccts for me) about it and get straight back to you. Did you know there is a micro real ale brewery in Hockley Heath?

Best regards
Dave

[AMCQ46]

What happens is the cams are fitted back at the wrong tdc in the sequence (in a 4stroke, there are 2 TDC's per cycle), so if you talk about crankshaft error, it is 360degrees out. But as the cams run at half speed of the crank, they are 180deg out.

On a single cyl bike this would be no problem, but on a v twin, the relationship between the firing stroke on each cyl can be important for high speed breathing.

Put simply, the engine is now running like a Big Bang configuration with both intake and firing strokes very close together. This empties the air box as the revs rise, hence it struggles to get past 7k. The bike was designed to have longer gaps between intake cycles so the airbox can fill up again, so needs the cam timing of 1 cyl moved by 1 rev

[StuartWags]

Hi everyone

Many thanks for all the info, the symtom is 'running out of breath' and the fitting details I used were from the Keiger website, I've only just brought a 'haynes' manual - ripped the cam timing pages out now.
I am having trouble in my brainbox thinking 'how can it be 180 out - it shouldn't run' I then wake up in a cold sweat at 3am.
Thanks for the offer of checking the timing AMCQ, I know its a ball ache stripping but I know there is nothing siezed, stripped or broken, I shall ask Adam (tech who fitted the ccts for me) about it and get straight back to you. Did you know there is a micro real ale brewery in Hockley Heath?

Best regards
Dave

It is easily done, i have done, when i did my first failed cct repair.

[midlifekrisis]

Many thanks for all the support and guidance, I think I know where I'm going now, go back to basics!
I have also been ferreting around regarding throttle position sensors & ignition advancers, winter is coming and there is a window of opportunity!
The sensor is an adjustment but the advancer a mod, what do you think of a 2 or 4 degree?

Dave
Midlifekrisis

[lloydie]

+4' advancer is good .
I have one fitted and I get a few more mpg and a few more bhp with it ,

They are a good mod if you can find one ,