Hey guys. After a ride on Saturday, I started wondering if my motor sounds a little "rattly". Since I have, essentially, zero experience I made a quick video of the bike at idle and posted to youtube for my brother-in-law to view. Frankly, I'm not convinced you can pick the rattle I'm concerned about but he suggested cam chain tension may need adjusting. Do you reckon just adjust it or is there another way to check the tension to confirm his diagnosis?
MC22s dont have a chain ... they have gear driven cams .... start looking elsewhere Hows the engine oil ? .... been changed lately? ... wat are u using in it?
Thanks @GreyImport . Oil level is good and the colour is good. I haven't changed the oil since the last service, which was done less than 500k's ago, and I don't know what the shop used but I could ask. I suppose it couldn't do any harm to change it and see what happens so I might get on to that.
Sounds like your oil is ok then ..... u can upload the vid here .... click on the media icon in the reply box here and put in the 'share' link from youtube
Like I say, I don't know if what I'm hearing actually came through on the video.... And maybe it's nothing but my tinnitus trolling me
Does the noise change or go away when you pull the clutch in, or put it in gear and hold the clutch in?
I have had a few different rattles on my mc22 that I have had to find, the hardest of which was the air box hitting that gas tank because there is 1 bolt that attaches to the frame near the left ignition coil which was missing. It actually sounded metallic also and varied in sound from revs. But that's the thing you need to try isolate a few things. 1. does it get louder or change when you rev the engine? 2. does it happen in gear with the clutch in or is it just neutral? 3. does it get louder or change when going different speeds? 4. does it change when you pull the clutch in? Here's some other things you might want to try before considering pulling the left and right hand side engine covers off. -Tightening the bolts on the header of the exhaust (most likely the problem in my opinion as it sounds like the valve train noise is escaping out of the headers from a vacuum leak based on what I'm hearing in the video). -Check the airbox is firmly bolted down -Check the radiator clip is in and not loose in any way -Check cables/cable connections e.g. choke, clutch, throttle leads etc -There are this little rubber grommets that are on the intakes just below where the carb boots are, which is where you connect the hoses for a carb synchronizer to, the same place the vacuum line from the gas tank goes to on cylinder 1. Ensure the rubber caps are on cylinder 2 and 3. On cylinder 4 there is a tiny screw instead of a rubber cap make sure its there. If that fails things get a little more serious and I would be pulling off the carbs and inspecting the boots, looking for any loose screws or metal floating around and at the ignition coils and tightening the spark plugs or even changing the spark plugs (I put that in bold because its a somewhat common cause of rattle) etc. That would be followed by removing the LHS engine cover and making sure there isnt any loose metal floating around in it and changing the clutch and clutch springs on the RHS. Obviously at this stage its a good time to put new oil in. That's how I would attack it anyway! Good luck.
Thanks for that @Damus , I'll see how we go. The idea about the header bolts really resonates with me, given I've already discovered loose bolts on the brake calipers after the last trip to the shop
Can you post a video of the exhaust ? If the carbs are in sync, you will hear a nice MC22 burble, I think Damus and Murdo are onto something there with syncronisation. As Damus said, check your exhaust is done up tight at the headers, might be worth dropping the headers off and checking there are exhaust gaskets installed Chris
Sorry for the delay - my router crapped out for no reason at all so I had to source and reconfigure a replacement. I have to admit that I assumed the carby's would have been synched when they were rebuilt a couple of months ago but I don't actually know. Can you rebuild the carbs and not synch them? In other news, there is no change to the sound when the clutch is used, nor when it is in gear. I can't do anything right now but this weekend I'll check the headers for gaskets and tight bolts. I have to say that, for the last couple of weeks it has been harder to start (not hard but not the instant start I've been used to) and I would imagine that would be a side effect if the headers were loose.
I can't hear any motor rattles in that video. Sounds like it needs a carb sync. A good indicator that the carbs need syncing is excessive handlebar vibrations - 4 cylinder bikes should be very smooth. You should also check all your carby and airbox boots to make sure they are secure and have no air leaks. If you want to have a go adjusting the sync, this is how I did it... Lift tank up out of the way and get the airbox off. With the bike not running, hold the throttle wide open. Eyeball the butterflies from directly above. On a bank of 4 carbs you first adjust the sync between 1&2 carbs, then between 3&4 carbs, and finally you sync the two groups (between 2&3). If the butterflies are out of sync, they won't line up with each other when the throttle is fully open. Once they look somewhat synced, start the bike and let it warm up for a minute or two or ride it around for a bit to get it up to temp. What you want to check for is how smoothly the revs rise as you very gently and slowly creak open the throttle. If the sync is not good it will struggle to rev cleanly and the exhaust note will sound uneven. Your goal is to get the bike to rev cleanly when slowly opening the throttle without any hangups. That's the DIY way without any fancy tools. The easy way is to get a bike shop to do it, or beg/borrow/steal some vacuum gauges and do it that way.
They do sound a wee bit out , a well Tuned mc22 should have a nice burble , check your exhaust first , sometimes it's the simple things
Does sound to be 'hunting' a bit at idle. Get the carbs synced and see if this makes a difference. Even after a carb rebuild, they will settle and need adjustments.
Good ear @Damus ! I've tightened all the header bolts to spec and one or two were significantly loose, especially on number 4. It started instantly after that, even though I used zero choke, and sounds much quieter and smoother. Importantly, the rattle I could hear has completely disappeared. Happy day! @Murdo , @Linkin and @kiffsta , I think you're right and it could still do with having the carby's synched so I'll get in the shop when I can but at least I can ride without too much concern right now. Thanks to everyone for the help.
Its starving for fuel, its not blowing any smoke and it sounds like its struggling when you rev it hmmm Also people, when you pull things off your bike PLEASE make sure you put them back on and tight. I have seen sooooo many people over the years forget to tighten things up and have there bike fall to bits down the road or worse them fall off due to them not correctly maintaining there bike.
