Primary chain specs

[Rczap]

Hey peeps, I am having some issues that seem to lead me to the primary chain being stretched. Does anyone have the spec for the chain? I cannot find anything about specs in the manual. All it says to inspect is gear wear. I pulled the cover off and the gears look good but the chain does have some slack in it. The clutch is slipping so that side is the next cover to come off. I plan on the full Barnett setup for the clutch.

[Bill L]

You mean belt, not chain, right?

Proper numbers are:

Drive belt slack (on the side-stand)  7.5 - 13mm (0.30 - 0.51 inch)

Drive belt slack (on a suitable stand)  14 - 21mm (0.55 - 0.83 inch)

Measure the drive belt slack when the drive belt has been pushed with 4.5kg (10 lbs) of pressure using a belt tension gauge.

[sundancer87]

The primary chain is used to drive the tranny that drives the secondary chain, in this case the belt as mentioned above.

http://www.boats.net/parts/detail/yamaha/Y-4WM-16139-00-00.html

[RangerRick]

You mean belt, not chain, right?

Proper numbers are:

Drive belt slack (on the side-stand)  7.5 - 13mm (0.30 - 0.51 inch)

Drive belt slack (on a suitable stand)  14 - 21mm (0.55 - 0.83 inch)

Measure the drive belt slack when the drive belt has been pushed with 4.5kg (10 lbs) of pressure using a belt tension gauge.

Wrong side Bill.  Pretty sure he is referring to, what the service manual on page 5-91 refers to as checking the middle drive But all it says is if they are damaged/worn to "Replace the middle drive gear, middle driven shaft and primary chain as a set". Does not say what is considered worn or damaged.

[Bill L]

You mean belt, not chain, right?

Proper numbers are:

Drive belt slack (on the side-stand)  7.5 - 13mm (0.30 - 0.51 inch)

Drive belt slack (on a suitable stand)  14 - 21mm (0.55 - 0.83 inch)

Measure the drive belt slack when the drive belt has been pushed with 4.5kg (10 lbs) of pressure using a belt tension gauge.

Wrong side Bill.  Pretty sure he is referring to, what the service manual on page 5-91 refers to as checking the middle drive But all it says is if they are damaged/worn to "Replace the middle drive gear, middle driven shaft and primary chain as a set". Does not say what is considered worn or damaged.

Thanks Rick... but if anyone needs the belt spec's there they are... 

[theurbanlegend]

You mean belt, not chain, right?

Proper numbers are:

Drive belt slack (on the side-stand)  7.5 - 13mm (0.30 - 0.51 inch)

Drive belt slack (on a suitable stand)  14 - 21mm (0.55 - 0.83 inch)

Measure the drive belt slack when the drive belt has been pushed with 4.5kg (10 lbs) of pressure using a belt tension gauge.

Wrong side Bill.  Pretty sure he is referring to, what the service manual on page 5-91 refers to as checking the middle drive But all it says is if they are damaged/worn to "Replace the middle drive gear, middle driven shaft and primary chain as a set". Does not say what is considered worn or damaged.

Thanks Rick... but if anyone needs the belt spec's there they are... 

Good save Bill 

[Rczap]

Yes I was talking about what is called the middle drive but the book refers to the chain and the primary. Totally confusing. If anyone can help me out that would be greatly appreciated. I will try to get some pics posted up of the slack that I am talking about.

[Skidmark]

How did you come to the conclusion that the middle drive is the problem? and what is the problem your trying to solve?

[Rczap]

Skidmark, the issue I am having is when I am slowing and the rpm's get low, the bike "jerks" . It is something that was not happening prior to this summer. I have 37k miles on the bike. The gears look good. Here are a couple of pics of the slack.

[Sweet Tooth]

I cant find anything in their that shows the specs on what it should be in my service manual. Maybe someone else has a manual that tells the how much slack it should have.

[Skidmark]

have you checked your actual drive belt? The Kevlar one on the left side of the bike. I had the same issue and it was because the belt was loose and when I cracked the throttle or even just let the clutch out the slack in the belt would get taken up all at once and create a whip like effect at the back tire. The manual you have is typically the same manual the Yamaha shop will use to fix the issue. So if it doesn't give you a spec, In my experience, they don't ever really need replacing. As well as when a chain stretches it should get steadily worse and worse, not a sudden issue all in one summer. Not denying your mechanical ability, just playing devils advocate.

[Fj_Ohio]

It would take a lot more slack than that to cause the problems you are describing. And I do not believe you will ever see the day you have that much slack.

[Rczap]

That is my dilemma, no spec on the chain slack. I checked the belt first and did some adjustment to make sure. I know Harley had some issues with theirs. They use automatic adjusters and some friends with '07 RoadGlides had some issues and got theirs replaced under warranty.

[Skidmark]

The next step would be to call a dealer, or better yet just give tejas a call and ask their techs. they should be able to give you the spec if there even is one, if there isn't then the chain isn't a wear item, and wont have a spec.

[Silent_Mike]

That is my dilemma, no spec on the chain slack. I checked the belt first and did some adjustment to make sure. I know Harley had some issues with theirs. They use automatic adjusters and some friends with '07 RoadGlides had some issues and got theirs replaced under warranty.

 

I've been a tech at both Harley and Yamaha dealers and you're kind of comparing apples and oranges.  The only reason they're really similar is because they both have a chain and two gears.  Harley primary chains are considerably longer and are a duplex roller chain.  Where as the Raider middle drive chain is an inverted tooth type (aka Hy-Vo, aka Morse type, Morse is actually just a brand name) which are less prone to stretching than roller chains.  Harleys need a tensioner partly because of the length and partly because of the type of chain, without one the chain is so loose it could destroy the primary case.  The shorter more precise fitting Morse chain allows Yamaha to get away without one in this application.  If there's no visible wear on the gears and it's not close to the case, I can't see Yamaha agreeing that there is anything wrong.

I don't remember the specifics but I do remember either a recall or an upgrade under warranty when Harley updated the auto tensioners.

Skidmark, the issue I am having is when I am slowing and the rpm's get low, the bike "jerks" . It is something that was not happening prior to this summer.

 

I've heard similar symptom descriptions before and it sounds like a result of deceleration enleanment, which is normal.  Most newer fuel injection systems have it as part of the mapping weather that's what they call it or not.  It's the way the FI system gradually leans out the mixture at zero throttle as the rpm's slow down toward idle.  At some point at low rpm but above idle speed the system switches from decel mapping to idle map and that's when you can get a noticeable jerk.  Some engines are more seamless than others.  Since large displacement, long stroke, v-twins have a chug-a-lug tendency at low rpm it can be very noticeable.  If you're looking for it you can see it on a lot of vehicles, especially bikes.

Which brings up my next point.  Not to be patronizing, but are you sure this is new, or now that you've noticed it you focus on it?  I'd suggest finding a dealer that'll allow test drives and ride a new one back to back with yours.  Or if you're willing to drop it off at a service dept. ask a tech to do it for you.  I had to do this once for a very adamant new-to-HD customer that was sure there was something wrong with his bike.  When I duplicated the "problem" on the bike on my lift and a brand new bike right off the show room floor he finally relented that it was a HD quirk that he just wasn't used to.

Skidmark is right about the lack of a spec in the manual.  If it's not in the factory service manual, then Yamaha probably doesn't consider it a wear item.  That doesn't necessarily mean there isn't one.  But a shop is only going to get it from Yamaha's dealer tech support.  And they're only going to give it out if a dealer has a reason to need it.  Like having a bike in their shop torn apart...  Honestly, IMO Yamaha service manuals aren't very good when compared to other brands anyways.    Idk if any of that will help, but good luck getting things sorted out.