4 into 2 Collector box - interconnected?

[vonny232]

Hi Folks,

I have a K4 and note the collector box has a "cross bar" which joins the two pairs of exhaust pipes.

Question: Is it just structural or are the two pairs of exhausts interconnected within the collector?

The reason I ask is due to my elusive Oil leak. My friend saw a puff of smoke from my left exhaust yesterday and am thinking of removing the two exhaust headers on the left side to look for any evidence of Oil or heavy carbon buildup. However, if all 4 exhaust pipes are ultimately interconnected then I would need to remove all 4 headers.

Once the headers are removed, I can borrow an endescopic camera from work to try and view the valve tops for clues (Dad thinks the leak comes from the Valve rims or stem seals).

Thoughts?

[Hooli]

They are linked as far as I know.

But as the bike leans on the sidestand the oil in there will collect on the left & tend to come out of that pipe, so it doesn't really signify much.

Have you still got the PAIRs system? that can drop oil mist in the exhaust if the airbox has any oil in (which it can from the crank breather).
Plus if you remove the PAIRs valves from the top of the cam cover you can see into the exhaust ports much easier than taking the headers off.

[gsxbarmy]

As Hooli says, and I agree totally regards what he says on the PAIRS system.

If not that, going on your original post though I agree with your Dad - possibly valve stem seals. I would have thought a quick check on the plugs would be the first thing to look at though.

[vonny232]

Cheers for the replies folks, I also thought that the left leaning stand might have an impact. What would I be looking for on the plugs? Would one be more scorched or something?

[grog]

Vonny, cant rem reading about your oil leak. Is it leaking or using oil? I always thought stem seals just leaked oil into cylinder and it got burnt off at start up, didnt really make motor use oil. Workmate, twin cam toyota cruiser motor, lots of ks. Was using litre per 1th ks. Could smell oil if following it. We all thought rings worn out. Blew head gasket. He got head serviced, new guides, seals etc. Now no oil use, no smell. Proved us all wrong.

[Hooli]

Stem seals can cause smoking on the overrun too, as oil is sucked past them.

[vonny232]

grog - Yeah I was asking about the Oil leak earlier this year.

The bike burns around half a litre ever 500-600 miles. No visible oil leak, and I have never really seen much puffs of smoke either (I only posted this because my friend saw the puff of smoke the other day).

The exhaust does smell a bit oily and the end of "both" the exhaust cans seem a bit sooty/grimey (is that normal)?

In any event, Is there logic in me checking the plugs and removing the headers first (to have a peek at the valve tops) before taking the bike to an engine mechanic for a full investigation?

[gsxbarmy]

Plugs if burning normally will have a beige colour to the electrode

If burning too much petrol (running rich) will be a dry black sooty look

If burning oil will still be black, but will have a wet look to it.

See this article - explains it all

https://www.championautoparts.com/Parts-Matter/automotive-repair-and-maintenance/how-to-read-spark-plugs.html

[vonny232]

Hi Folks, I got a side question.

Im thinking of replacing the header bolts with better quality ones.

Can people reccomend the best place to buy some hardened? Stainless? whatever bolts?

[froudy]

Hi Folks, I got a side question.

Im thinking of replacing the header bolts with better quality ones.

Can people reccomend the best place to buy some hardened? Stainless? whatever bolts?

Just go to a local nut and bolt supplier, they'll be far cheaper than sellers on Ebay etc. 8 stainless bolts will only cost you about £3-£4.