Weird fluttering/clicking noise and poor accelerat

[kbcr3]

So, this just started yesterday afternoon.

At idle, the ruckus is fine. I don't hear anything odd. As I hit the gas from a dead stop, the ruckus accelerates sooo slowly. 0 to 30 times have to be about 20 seconds. It gets to top speed, but it takes forever. As I get to about 15mph I start to hear an odd ticking-type fluttering noise. It seems to be consistent with rpm. It stalled and died the other night at a light. It started right back up though. It has 598 miles. Nothing has been modded. I changed the oil two weekends ago to synthetic, but have used the scooter about 20 times since then. Is this the whole valve shim issue?

[kbcr3]

on my ride home this evening, it died at one of the lights and struggled for another minute or so. after about 4 minutes of riding, the ruckus was fine. no fluttering/ticking noise. accelerated normal too. i'm hoping this was just a temporary thing. i took it on a longer route home to see if it started struggling again...and it didn't.

[chanito]

might have been bad gas

[kbcr3]

it was doing it again slightly this morning. not as bad. it didn't stall, but it was the same tapping/fluttering noise. it went away by the time my commute to the train was done.

it's going on a 21 mile ride this afternoon, so it had better not crap out on me!

[Dandy Dan]

The noise sounds to me like one/both of your valve gaps are too big so there is a click everytime the cam lobe wacks into the valve which is why it gets louder as your gaps grow and as your RPMs rise.

[kbcr3]

dandydan said:

The noise sounds to me like one/both of your valve gaps are too big so there is a click everytime the cam lobe wacks into the valve which is why it gets louder as your gaps grow and as your RPMs rise.

would that also explain how it seems to get better when the ruckus warms up? once it's completely warmed up, it's fine. unfortunately, my commute on it is only like 1.1 miles, so it never gets to completely warm up.

i guess i have to adjust the shims. how hard is that? also, my ruckus is still under warranty. i have like a month left. should i just bring it to honda and let them fix it?

[Dandy Dan]

You could let Honda fix it but it will be approx $100.

If you want to do it yourself you just need to remove the seat and floorboard to get engine access and then just remove the front cover on the engine.

Then just use the kickstarter to rotate the engine until the piston is all the up (you can check this by pulling the spark plug and sticking a screwdriver in to feel or there are some marks that will line up in the engine you'll see). Then just use a 'feeler gauge' (basically a bunch of thin metal popsicle sticks of different thickness) to see what size the gap is. Then just compare it to the specs (.10mm intake (top) and .19mm exhaust (bottom)) and then you'll probably need fatter shims to reduce the gaps so just slide the rocker arm sideways out of the way and use a magnet or pliers to pull the shim out but don't drop it in the engine. The thickness should be written on the shim so as long as it hasn't worn off it's just some simple math to see how much thicker you need the shim.

Ex:

You measure your intake gap at .22mm
The spec is .10mm
You're off by .12mm
Your current shim is 210 (2.1mm)
You need to add .12mm to close the gap to .10mm
Buy a 222 shim.

[kbcr3]

wow. that was a lot more straightforward than the version i read in the tech section of the forums.

how long is this going to take? also, am i going to lose all the oil too?

[Dandy Dan]

Adjusting your valve shims is a bit tough to explain but it's really pretty simple. Once you've done it once it's a breeze...the only annoying part is that you kinda need to bend your feeler guage shims to get them in there because it's pretty tight quarters.

One other thing is that our engines are 4-strokes which means that 1/2 of the time when the piston is all the way up it's just finishing it's compression stroke (which means both valves should be fully shut which is what you want) but the other 1/2 of the time it will be right after the piston finishes rising and pushing the exhaust out and is ready to suck the new air in...you don't really want to be on this stroke because there is a bit of overlap where the exhaust valve closes a bit late and the intake one closes a bit early so they aren't actually 100% shut even with the piston is at the top. It's pretty darn close and you can still do your valve adjustment but it's best to do it on the compression stroke.

Keep in mind this is how our engines work:
Piston goes down (sucks in air)
Piston comes up (compresses air)
Piston goes down (explosion)
Piston goes up (pushes exhaust out)

So just turn the engine over slowly with the kickstarter and watch the intake valve open and the piston will go down. Then you'll see the intake valve shut and the piston come up and that's when you want to stop it and do your shimming.

To answer you're questions, no you won't lose oil, everything up there is oil coated because it flies up via the chain but there won't actually be oil dripping out...no worries.

Also, once you've got the seat and floorboard off an expert could do it in 15min but since it's your first time allow 45min to sit down and get some good lighting and carefully measure things. You don't want to be rushing and dropping little shims into the engine (although you can usually get them out). The longest wait is when you figure out what shim you need but you need to get it from your dealer and sometimes they'll need to order it. A ghetto way to temporaily solve this is to use a little piece of your feeler gauge as a mini shim. ie. If your gap is .10mm too big then cut a little circle from your .10mm feeler gauge and put it under the shim so now the gap is just right. It's a ghetto way to do it but it works fine...I've actually got my exhaust valve done this way right now because I didn't have the right shim last time. Oh, a new shim is about $5 which isn't a lot of money but it is considering you get such a tiny piece of metal.

Anyways, you're probably all confused now but it's really not that bad. Just dive in and try it and if you get confused post and we'll help you. One thing to remember is don't do this when your engine is hot because the whole idea of having gaps is so that when your engine heats up and expands the gaps can account for this and it doesn't mess up your valves. Finally, try not to knock the rubber ring out of the engine cover because it can be a pain to reinstall.

[kbcr3]

i checked the valve clearance this weekend and it seems fine. i was barely able to get a .005 feeler gauge in there.

any other ideas?

to reiterate, it runs fine once it's warmed up completely. being that my commute is just over a mile, it doesn't get a chance to warm up completely.

if the valve clearance is fine, then what other possibilities are there?

[Dandy Dan]

kbcr3 said:

i checked the valve clearance this weekend and it seems fine. i was barely able to get a .005 feeler gauge in there.

0.005 is about .12mm so that's good for the intake but did you check the exhaust? or was this the exhaust?

[kbcr3]

i have no idea. i checked the valve that's on the top of the motor. i'm not sure if that's the exhaust or intake. i just realized that i neglected to check the other one.

[chanito]

The valve on top is the intake, the one that gives the most problems is the exhaust or lower one

[kbcr3]

dang it!

on a lighter note, i ran it for 10 miles this morning and it seemed 100% fine. i put a tank of fresh gas in about 2 days ago. i only used about 4 miles of gas between then and now. it might have simply been some bad gas.

[Dandy Dan]

Nothing cures like time!

About the lower valve (exhaust), the reason this gap is spec'd bigger than the top one (.19mm vs .10mm) is because the exhaust valve gets a lot hotter than the intake one and expands more as your engine heats up. If you gap is say 0.05mm then it'll run fine when you start it up but over time as the engine heats up and the valve expands that gap will shrink to nothing and then eventually your valve won't be able to fully seal. Or the opposite could be true, if you gap was too big....like 0.30mm it would start off clicking and not making max power because you wouldn't have quite as much lift but as then engine heats up and the gap shrinks it might run okay.

Anyways, the point is that you gap could be off and your bike might still run good sometimes. 10 miles is a decent trip though so if it seemed 100% then perhaps it is.

[kbcr3]

this morning, it was fine right from the start. no fluttering. no clicking. i got on the gas right as i pulled out of the driveway and it responded normally.

[Dandy Dan]

Generally the valve gaps shrink over time which means they are fine when you start the bike up because everything is cold and hasn't expanded and then once the bike warms up it can become a problem. If it's only a bit too tight though you may not notice because as the bike warms up in runs better in other aspects like the bearings roll smoother, the drive belt rides better and the carb has an easier time vapourizing the fuel so these benefits may be cancelling out the negative performance of the valves so you don't notice a reduction in performance as the engine heats up.

With that said, your scoot sounds like it's running fine and it's unlikely what I posted above is true, I just posted that so you're aware things might not be 100%. Even if this is a small problem it isn't very serious and so you could just wait until it becomes more obvious.

If I were you I'd just enjoy your Ruckus and if something does happen down the road let us know. Probably the easiest way to tell if you valve gaps are too tight is if your engine is having a hard time idling once it's warmed up and it's not because of the idle screw. When your engine is cold it doesn't idle that great because the carb can't vapourize the gas as effectively and because the cold start enrichment valve is crude. If you're engine is fully warmed up (10+ min of riding) and it's idling poorly and it's not just set too low then it could be your valves because tight gaps are the most apparent at low RPMs because the lower engine speeds allow more time for the air to hiss out past the valve(s) and kill your compression. It could easily be something else too though like bad gas though...

Too loose of valves is easier to tell because as they get looser you'll hear a ticking sound that increases in frequency with your RPM and it really gets loud at top speed ie downhills. As your gaps grow it gets louder and louder and you'll notice this well before something catastrophic happens.

[chanito]

Thre you go the Maestro has spoken ;D