Yamaha SCR950 Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
884 Posts
Discussion Starter · #1 ·
Did the 600 mile service this afternoon and it went pretty smoothly. The add-n skid plate made the oil change a bit fiddly, but I expected that. Rokrover 's tale of the boogered up oil filter pipe from the factory had me worried when my bike's filter turned with resistance for a few revolutions before freeing up (whew) and coming off normally.
The once over:
Bolts - tight all around. Nothing scary found.
Spokes - all made a nice, happy *ping* sound when rapped with a screwdriver handle.
Throttle body synchronization: Off just a hair by my LCD balancer's display. Only took a minute to get them even and the engine sound changed, indicating it was off enough to have bothered with it.
The rest was uneventful as I sort of expected.
All done? I washed it and went for a short ride.
:grin2:
 

·
Registered
Joined
·
155 Posts
Coincidentally, I'm also doing the 600-mile service. Today was the belt tension and rear wheel alignment. First I used a hydraulic jack under the rear frame rails with bike upright in a stand to spin the rear wheel to find the tightest spot. Then the bike was lowered back on the rear wheel to compress the shock as specified in the manual. The belt tightens as the swing arm moves up. I used a 10 lb compression spring gauge to check belt displacement in the guard window. It was in spec at 8 ~ 9 mm so no adjustment was necessary, thank goodness. The manual says to remove the muffler to loosen the 27mm axle nut but this is not necessary. Tomorrow it's on to synchronize the throttle bodies. As for the steering head bearings, there's no obvious play or binding so I'll leave well enough alone. Everything else is pretty routine. It's a well assembled bike, other than my unusual warranty glitch with deformed threads on the oil filter mounting stud.
 

·
Registered
Joined
·
884 Posts
Discussion Starter · #3 ·
Coincidentally, I'm also doing the 600-mile service. Today was the belt tension and rear wheel alignment. First I used a hydraulic jack under the rear frame rails with bike upright in a stand to spin the rear wheel to find the tightest spot. Then the bike was lowered back on the rear wheel to compress the shock as specified in the manual. The belt tightens as the swing arm moves up. I used a 10 lb compression spring gauge to check belt displacement in the guard window. It was in spec at 8 ~ 9 mm so no adjustment was necessary, thank goodness. The manual says to remove the muffler to loosen the 27mm axle nut but this is not necessary. Tomorrow it's on to synchronize the throttle bodies. As for the steering head bearings, there's no obvious play or binding so I'll leave well enough alone. Everything else is pretty routine. It's a well assembled bike, other than my unusual warranty glitch with deformed threads on the oil filter mounting stud.
Yes, it does seem to be a well-made machine!
I'd bought a Harley-Davidson belt tension gauge for my girlfriend's V-Star 950 when she got it back in 2013. It's a 10lb. gauge and was actually less expensive than the Motion Pro one I've seen for sale and might actually be the same tool! =)
On her bike, the belt is wider than the U-shaped part of the plunger. So, I took it off, flattened it out and re-bent it out with a wider opening. As-is, it works on the Bolt or SCR just fine.
 

·
Registered
Joined
·
155 Posts
The U-shaped part of my plunger is too wide to fit inside the belt guard (my ex-HD Sportster had a wider belt) so I flip the tool upside down and press the pointy end against a 1" square thin wood shim to evenly load the belt. These drive belts must not be twisted or bent through too sharp an angle, despite internet lore to check tension by seeing how far you can twist the belt sideways!
 

·
Registered
Joined
·
884 Posts
Discussion Starter · #5 ·
The U-shaped part of my plunger is too wide to fit inside the belt guard (my ex-HD Sportster had a wider belt) so I flip the tool upside down and press the pointy end against a 1" square thin wood shim to evenly load the belt. These drive belts must not be twisted or bent through too sharp an angle, despite internet lore to check tension by seeing how far you can twist the belt sideways!
I think the belt twist test thing only applies to traditional car fan belts. Even with those, there's gotta be a better method.
I had two Kawasaki EN450s with belt drives before owning a Sportster myself. I've found that once you get the tension right, leave it alone. It'll be fine until the next tire change. That and don't ever even think about putting anything on the belt like a belt dressing, etc... (Like a buddy did with his!) Water from washing it or riding in the rain can make them squeak a little for a while before they quiet down again. That's perfectly normal and okay.
 

·
Registered
Joined
·
884 Posts
Discussion Starter · #6 ·
Oops! I got it backwards.

The U-shaped part of my plunger is too wide to fit inside the belt guard (my ex-HD Sportster had a wider belt) so I flip the tool upside down and press the pointy end against a 1" square thin wood shim to evenly load the belt. These drive belts must not be twisted or bent through too sharp an angle, despite internet lore to check tension by seeing how far you can twist the belt sideways!
Wow, I goofed!
Just found the tension tool and I could've sworn I made the U-shaped end a bit wider. In fact, I did the opposite! When she gets home, I'll look and see if it was to clear the belt guard. $0.05 says it was. LOL
-eddie
 

·
Registered
Joined
·
155 Posts
Just found the tension tool and I could've sworn I made the U-shaped end a bit wider. In fact, I did the opposite! When she gets home, I'll look and see if it was to clear the belt guard. $0.05 says it was. LOL -eddie
You may just be $0.05 richer :) My first thought was to use the wider tool by removing the belt guard. Doh, then I'd lose the setting window! A contrived solution that adds complexity, unlike flipping the tool upside down.
 

·
Registered
Joined
·
31 Posts
Throttle body synchronization: Off just a hair by my LCD balancer's display. Only took a minute to get them even and the engine sound changed, indicating it was off enough to have bothered with it.
So I need to do the service this month and This is my 1st Fuel injected bike. Suggestions of what I need to get throttle body synchronized? Tools or videos I should look at? Any guidance would be appreciated.
 

·
Registered
Joined
·
884 Posts
Discussion Starter · #9 · (Edited)
So I need to do the service this month and This is my 1st Fuel injected bike. Suggestions of what I need to get throttle body synchronized? Tools or videos I should look at? Any guidance would be appreciated.
I started out with one of these years ago.
Twinmax Carb Carburetor Balancer Adjuster Synchronizer | eBay
Motorcycle Consumer News(?) did a comparison between it and the factory $$$$ BMW balancer used on R-series bikes and the TwinMax was just as good to them.
It's very simple to use, too.

On a SCR/Bolt, you remove the air filter cover, filter and backing plate to get at the throttle body. Each of the intakes has a small port for this purpose. One's capped off with a small, rubber cap. Remove the cap and connect one balancer hose to it. The other already has a hose connected to it. I used a small plastic vacuum line T fitting from an auto parts store & connected the original hose to one part, the balancer hose to the other and a short section of hose I had to reconnect things to the bike.
To begin: (Bike thoroughly warmed up, but engine off)
Turn on the balancer and set the sensitivity to it's most sensitive setting and use the Zero knob to center the display indicator.
Next, turn the sensitivity all the way back down and crank the bike.

The indicator will "bounce" back and forth evenly at this point, or should. If not, there's a small brass air bleed screw on each side of the throttle body (photo). One may have paint on it. If so, turn the other one slowly counterclockwise and observe the indicator. If it favors one side more, go clockwise with the screw very carefully until it either centers of the screw stops.
Caution: If the screw stops before the indicator centers, do not force it any farther or risk damaging the throttle body.
Turn the other screw instead.
The process is a simple center, raise the balancer sensitivity, re-center the balancer, increase sensitivity and repeat until the balancer runs out of sensitivity.
Do it one or twice and it takes about a minute.
The knowledge gained and money & time saved will more than compensate you for the $ spent.
Done? Disconnect & replace everything and go ride!


**
When the shop where I hung out closed, the owner gave me a LCD readout balancer that I'd used there on customer's bikes (other photo). It was way more expensive and can do 2, 3 or 4 intakes at a time. While a hair more accurate, it's also a pain to use on some bikes due to the ease or lack of access to the battery. I simply hook it up to an old 12V bike battery I have in the storage room instead.
 

Attachments

·
Registered
Joined
·
884 Posts
Discussion Starter · #10 ·
Final Notes:
The TwinMax says Electronic Carburetor Balancer, but it works fine with fuel injection, too.
Example: A retired Army CSM and Ranger Hall of Fame member brought his BMW GSA by to have the throttles synced.
I Googled the BMW particulars and learned never to try and balance a throttle body with the actual throttle plates like one might with carbs.
They may adjust fine when warm. Once the engine cools off, the plates can seize in the intake bores.
Not a cheap fix!
Instead of the tiny brass air screws on our bikes, they have literal big brass ones.
Turn in until lightly seated, back out 2 turns on a GS ( 1.5 turns on a street only boxer), start the bike and adjust the balance from there.
Anyhow.... "Sam" was very happy with how the Beemer ran after only a couple of minutes' work.
It's best to make the former CSM of the 82nd happy.
Making him mad is probably a very bad thing.
=)
 

Attachments

·
Registered
Joined
·
1,206 Posts
The knowledge gained and money & time saved will more than compensate you for the $ spent.
Done? Disconnect & replace everything and go ride.
Every forum has one Eddie, and I'm glad you're here. Another consicely written piece with no fluff and filler. All good stuff. Ride On Eddie!
 
1 - 12 of 12 Posts
Top