Why is my motorbike going pop?

just been out for the first ride on my motorbike for about 6 months. took it gentle to start with but then once I was happy I wound it up and found that if I give it some stick for about 5 seconds or so then drop the throttle I get a loud pop from the exhaust.

never had it before but then its never stood idle for 6 months before either

any ideas what it could be?

Anytime I've had this it's a leak in the exhaust system. Once had a slightly loose header on the bonnie and the backfire was like a bomb going off! Was quite entertaining for a wee while.

engine about to fail.
be careful.

😮

running a bit rich, unburnt fuel in exhaust?

my Kwak use to do that in any tunnel, but probably me flicking the kill switch off/on had something to do with it 😆

Humm, I know there is a slight hole in the exhaust where it goes from four tubes to one so that could make some sense

mine does some massive backfires on start up if I have overdone the choke

Start up was fine, took a lot of choke but got there pretty quick, the pops only happened when I rolled off the throttle after giving it some stick.

I had this on my Fazer6. The header pipes had corroded and a small hole had appeared. Got some second hand ones of ebay, and problem gone.

Funnily enough its a fazer 600

Prob with the Fazer 6 is the down/header pipes are mild steel and if brought within 5 miles of a a grain of salt will fall apart. Have a look around the header pipe welds as that is where they usually blow through. I was just fixing up to sell, but if your planning on keeping it then it might be worth investing in some stainless steel replacements.

You might be able to get it welded if lucky tho.

Cheers for the info, I've had my eye on some ss ones, seen them go for about 200 on ebay so I might have to invest in some once I'm back from Japan, in the meantime I've got some exhaust putty and some heatproof paint so I guess I'll just patch it.

Is the odd pop going to cause any issues? I'm looling to commute on it as I'm sick of the traffic jams in / around glossop so I'll be doing 80 – 400 mile a week dependant on weather

Is the odd pop going to cause any issues?

….

Not really. It will just shorten the life of your already holed exhaust.

Not really. It will just shorten the life of your already holed exhaust.

+1.

…plus you will have the fun feeling of scaring the crap out of everyone as you slow down for junctions/roundabouts etc

well I'll see what i can do about patching it for the time being, thanks guys

The air leak is a stone-cold MOT fail if your tester notices/cares, mind.

I guess the other possibility, if it's old enough, might be a sticky choke cable as it's been sat around, that could kick extra fuel into the exhaust. But you should notice that from other symptons, fast idle etc.

Could it make the engine run hot enough to burn valves? Or is that only from the days of old british bikes?

@TJ – yes this is possible……if the hole in the exhaust was big enough. But, the OP says the odd pop….he hasn't said that the bike sounds any different….plus he says he's going to 'patch it' short term.

So I reckon he'll be OK.

MOT is a while off so that's no issue, everything else seemed ok, gonna run it a bit more tomorrow and get that patch on it at lunch

You'll be fine patching it up until you can get it sorted properly. If you want a new exhaust then give me a shout. My old man owns and runs an engineering workshop Johns Engineering and we would probably be able to help you out and save you a bit of cash.

Zed.

Cheers

its sick of you playing classical…

ill get my coat.

@ zedsdead, I've said this before and i'll say it again (this is an assumption, having never been to your shop) can you bottle the aroma of your shop please? I feel it would be just fine in my little shed, despite not having anywhere (by a long way) near as much in it.

check valve clearances? doubt it would have slipped anywhere if sat still.. but worth a wee check?

I took it to work and back yesterday (about 80 mile) and it never made a sound so I guess all is good but I'll still patch the exhaust

| love it when things fix themselves.