Yamaha SCR950 Forum banner

1 - 20 of 23 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter · #1 ·
I'm sure I know the answer, but these things are tappy as ****, right? I know that was the case for my old 650. Just want to feel better about life, so tell me it's not already out of spec, valve-wise. Only 690 miles on it. :)
 

·
Registered
Joined
·
251 Posts
Do you mean that you can hear the engine lightly clicking as you're riding at high speeds? If so, I've heard mine since day one, mile zero and that hasn't changed since my first oil change. I figure since I'm sitting on top of an engine that I'm going to hear the valves pumping so I don't think it's a problem ¯\_(ツ)_/¯
 

·
Registered
Joined
·
1,209 Posts
I'm sure I know the answer, but these things are tappy as ****, right? I know that was the case for my old 650. Just want to feel better about life, so tell me it's not already out of spec, valve-wise. Only 690 miles on it. :)
Yep, notoriously tappy.....chill.

Started mine up today before putting my ear plugs in (normally the other way round), and even thought to myself that I’d forgotten what a noisy lump it is (just coming up on 3000, by the way).

(A shot from today’s trip out, below).
Ben
 
  • Like
Reactions: higworld

·
Registered
Joined
·
1,177 Posts
Stumbles at Start Up

I'm sure I know the answer, but these things are tappy as ****, right? I know that was the case for my old 650. Just want to feel better about life, so tell me it's not already out of spec, valve-wise. Only 690 miles on it. :)
I just thought about that today when I pulled mine into garage. It was clattering quite noticeably. I am at 2,300 miles. My Virago Vtwin clattered a lot too.

What bothers me more is that mine has developed a bit of a stumble at start up. Meaning that as soon as it fires up it nearly stalls out. Actually it has stalled out at start up one time. It didn't stumble like that until recently, like in the last 500 miles. It has had no attention outside of oil/filter change and the K&N intake. But the intake has been on for a long time, so I doubt that is causing this recent stumble at start up.
 

·
Registered
Joined
·
372 Posts
Oh, how it taps! My old Ninja was known for making a similar sound, the "Kawi Click," that indicated a loose cam chain so at first I thought I had bought a lemon. Nah, you're fine.
 

·
Registered
Joined
·
1,177 Posts

·
Registered
Joined
·
1,177 Posts
What a D_ _ k! Hey Schu, my SCR has developed a stumble upon start up as well! I have the same "mods" as you. Once it's warm, it's fine.
Exactly. And you have had your intake swapped for a long time too, so I still don't think it's related. I'm wondering if it is a bit out of sync. Still miles ahead of the old convention carbs with a choke.
 

·
Registered
Joined
·
251 Posts
What bothers me more is that mine has developed a bit of a stumble at start up. Meaning that as soon as it fires up it nearly stalls out. Actually it has stalled out at start up one time. It didn't stumble like that until recently, like in the last 500 miles. It has had no attention outside of oil/filter change and the K&N intake. But the intake has been on for a long time, so I doubt that is causing this recent stumble at start up.
Believe it or not, that intake kit you installed might actually be what's causing your stumble and occasional stall-out. The extra air flow you're giving the engine coupled with variations in temperature and humidity in the air have thrown off your combustion ratio just a tad, i suspect. If you experience the problem in the mornings when the air is full of moisture then this is probably the case.

I had a Honda Ruckus scooter that I heavily modded with swapped air intake that would stall out on cool, humid summer mornings when I tried getting it running but giving it a little extra throttle warmed things up quite a bit and I was good to go. I'd never have a problem in the afternoon unless the humidity level was near 98% (pea soup), but then I just rejetted and tuned the carb so everything worked just fine after that. Small engines are finicky and need just the right amount of air/gas mixture in order to burn and run perfectly without re-tuning, and our v-twin is no different.

I wouldn't worry about it, though. Maybe you're running a tad lean with the new intake but by 2-3%. Not enough to do any damage. I'm no mechanic though, so take this with a grain of salt. I'm a Psychologist and a leatherworker for christ-sake!
 

·
Registered
Joined
·
675 Posts
Oh great! NOW we find out he's a physcotic leather worker!!🤡
I think you hit the nail on the head, though. That little bit of extra air could be throwing things off. Makes me think back to my first real street bike, a '71 Triumph Tiger that I had to run with the choke half on until I could afford to have it tuned up. Turns out that the points were shot and the extra fuel would compensate for that. Who knew?! I have to admit that when I read about some of my fellow SCR owners sending their ECU in to get reflashed, I think back to my old Triumphs and how finicky they were and how WE simply compensated for their poor driveability. Never let the throttle fully close in between shifts, NEVER-EVER use the choke when it's warm, etc. I guess we've become a little spoiled with all of this technology at our fingertips! I gotta go, the mosquitoes are biting the s_ _ t out of me!
 

·
Registered
Joined
·
1,209 Posts
Agreed the air filter is probably throwing the air/fuel ratio out a little, but strange that they didn’t start choking occasionally at start-up as soon as you made the mod. K&N (other filter manufacturers are available, for the pedants out there) also state there shouldn’t be any deleterious effects after the install.

Other thing I’d be looking at is your battery. Are you hooking them up to a tender every now and again (or all the time!!)?? Making lots of short journeys so the battery never has chance to fully recover from start-up?

My old Harley used to be very sensitive about any dip in battery performance, and usually made itself known at start-up. Now, that was a massive v-twin, but the battery was equally massive too.....all things being square, probably similar ratios of CCA in our smaller battery compared with engine size/compression etc.

Just a thought.
Ben

PS - @Schu......no it’s not!!!
 

·
Registered
Joined
·
43 Posts
Discussion Starter · #12 ·
Thanks all. I think every one of the who knows how many bikes I've owned has had some noise-weirdness that bothered my OCD. :)

My first bike, a Honda CB360T was loud as ****. Came to find out it was a known cam chain issue. I knew the SCR tapping was normal, but wanted to check. I don't really trust dealerships during bike prep. LOL!

I do miss my old R1100GS taps though. For some reason, that boxer engine tapping away was kinda relaxing ....
 

·
Registered
Joined
·
372 Posts
I occasionally get a brief dip in power a moment after starting up, and my engine/intake/etc are all stock. It hasn't been bad enough to stall, but it does mean when I turn out of the driveway into traffic, I don't get the amount of acceleration I'm expecting. I haven't yet correlated it to any particular ambient conditions.

It usually happens like this: I shift into second gear, and I start accelerating normally, but once I'm at around 20mph, the power dips for a moment, and it takes 2-3 seconds longer than usual to get up to third gear speeds. Is that what it's like on your SCR?

I agree with Jevers; I do not miss my old bike and its old bike problems. I love my high-tech-yet-old-school SCR. (Just reached 8000 miles!)
 

·
Registered
Joined
·
675 Posts
Also, when I turn the ignition switch off, I hear a strange sound. It's hard to describe, but it almost sounds like electricity crackling.????? Anyone else????? Maybe it's the EFI?????? I dunno. 🤓
 

·
Registered
Joined
·
884 Posts
A bit loose is always preferred over any tight when it comes to valves.
Some engines are quite noisy even when things are perfect.
Apples to oranges, but my 04' Sportster 1200 had hydraulically adjusted valves and clattered like there were
bottle caps under the valve covers. LOL

I checked and adjusted my girlfriend's V-Star 950 valves at around 15.5k miles and they were lightly ticking before and after.
That engine is the parent mill for the Bolt and the SCR. So, external aesthetics aside, the internals are pretty much identical.
Below are pics of the measurements and the valve train itself. I left the exhausts as-is, a wee on the loose end of the specs and brought the intakes to the middle.

Tip: If the valve lash requires adjustment, I've found it's a good idea to check the throttle body synchronization afterward as it can change.
 

Attachments

·
Registered
Joined
·
884 Posts
Thanks all. I think every one of the who knows how many bikes I've owned has had some noise-weirdness that bothered my OCD. :)
(snip) I do miss my old R1100GS taps though. For some reason, that boxer engine tapping away was kinda relaxing ....
Just thought of another possible cause of an engine behaving differently: Fuel quality. I don't know about others, but I tend to buy gas at the same few stations. Occasionally, I'll get some that leans to higher alcohol content than normal. The Super Tenere (liquid-cooled) will run observably hotter as well as have occasional hiccups in power delivery. I can get different gas and it calms right down.

I'm with you on the boxer sound! I rode a R75 briefly while a Honda was in the shop and the stereophonic clatter was actually kinda pleasant when just tooling along a back road. =)
 

·
Registered
Joined
·
372 Posts
Also, when I turn the ignition switch off, I hear a strange sound. It's hard to describe, but it almost sounds like electricity crackling.????? Anyone else????? Maybe it's the EFI?????? I dunno. 🤓
Yeah, I get that sometimes. Maybe two or three "ticks?" No clue what it is.

And since we're on the subject of perplexing sounds, what is that noise you hear if you turn on the ignition with the killswitch off?
 

·
Registered
Joined
·
1,209 Posts
And since we're on the subject of perplexing sounds, what is that noise you hear if you turn on the ignition with the killswitch off?
Are you sure you don’t mean with the killswitch on?! That’s the fuel pump priming (doesn’t do it with the killswitch off).

Ben
 
  • Like
Reactions: eddie

·
Registered
Joined
·
229 Posts
Twins are louder than 4 cyl usually because you hear each clack of each tappet. However that plastic cover and the fact its in the middle right under the frame and tank could quieten it a bit. But inspite of being a shim over bucket, and the head completely being inside the frame and a huge gas tank over it a GS500 makes a fod gorsaken racket.
Those old air oil cooled GSXR's were very loud too but you heard 16 valves and they all blend into some sort of scratching and not distinct tapping. Set the clearances correct, and hear the noise. Then if the noise gets louder they're looser and if it gets quieter its got tighter.
 

·
Registered
Joined
·
1,177 Posts
Gotta Love'm

Twins are louder because you hear each clack of each tappet............................ Then if the noise gets louder they're looser and if it gets quieter its tighter.
All this discussion about loose clacking, tight tapping, fod gorsaken noise makes realize why we all say "I'm gonna take her out for a ride" or "She burns a little oil" or "I took her in for a check up and she's ready to roll"

Yes sir as noisy as they are we still love'm and we don't want to be without one. Oops. Gotta go. Here she comes now.
 
  • Like
Reactions: Krixtoph
1 - 20 of 23 Posts
Top