Stuttering.. Thought it was the clutch, now I'm not sure.

Well, I'll start of with how it began...

A few weeks ago the bike was acting like it was running out of gas, and/or starving for fuel. After the third night riding it home from work I noticed it mostly did it the fist few miles before it smoothed out. Then one day after visiting a friend for a brief 10-15 minutes I went out and it did it again, and the bike was obviously still warm. I checked the fuel and had plenty.

I decided to do some testing when it occurred. First thing I did was, as it sputtered, I pulled in the clutch to see if it would stall out. It did not. I re-engaged the clutch and the sputtering returned. I immediately thought clutch. So this time I slowed down and found neutral and then popped her into 2nd with a quick release of the clutch and it rode ok after that. Still I thought clutch. Sooo, I ordered some clutch plates. Installed them without a hitch. However had a bit of trouble getting the throwout lever set perfectly.

I thought I had it! I took her for a ride and all was well. I even went home that night boasting to my wife all was well and we could go for a ride this Sunday... My mistake... After a brief warm up we set off and the sputtering immediately returned... I turned around and decided to pull the carbs... again... Even though I had meticulously cleaned them about a month ago. All was well. Clunk test, clear jet passages, sync, float adjustment, etc...

Put the carbs back on, mano'ed em, and colortuned. Problem still persists. She starts right up beautifully and idles great. Revs perfectly.

What am I missing? New springs? Valves? Not brushing up the friction plates?

Tonight I went out to my shop to stare and ponder what could be the problem. Upon pulling the clutch lever in while peering into the oil fill hole with a flashlight, it seemed to be working properly... Then I reached down and decided to push down on the throwout lever? I was able to push it down another 1/2 inch or so. I checked to see if the clutch cable was binding so I loosened it up and found that it was not the reason the throwout lever was not returning completely. Is this the spring on the throwout levers fault? The clutch springs being to weak? As far as I can tell(and I'm pretty analytical) I got the lever positioned pretty much exactly the way it was when removed. It's as if the problem hasn't changed a bit, and I know my carbs are legit, but am wary about that clutch still.

Oh and on a side note... After parking it after the last test run I could hear the gas cap squealing(for lack of a better word) as it was sucking in air. I opened it, took it apart, and found that I was able to blow air past the breather holes on it with the rubber depressed. Could the gas cap not allowing air to enter the tank fast enough be causing what I describe? As a test, could I simply keep the cap closed and pull the fuel line and turn it on pri to see how well it flows or is this idea moot?


Sorry for the long post and all the questions guys. I'm just a man with maybe a few weeks of riding weather left in dire need for some help.

Thanks in advanced.

 

Re: Stuttering.. Thought it was the clutch, now I'm not sure

This sounds like a real possibility. You may want to run around with the gas cap un-latched (or open) nad see if the problem is eliminated, in which case you know the culprit..............the gas cap must be able to "breathe" freely or otherwise the fuel "vapor locks" inside the tank.

 

I'll give that a try tomorrow chacal. Thanks. I'll let you know of my findings.

*edit* Is it possible there is enough venting to allow her to idle and rev without a hitch yet sputter under load?

 

Possibly. Idling and revving without a load use an incredibly tiny amount of fuel.

 

The anticipation is killing me. *puts on a coat and heads over to the shop*

I'll let you know in a few minutes if it's a gas cap venting problem.. I just cant stand the thought of something so simple and easy to test keeping me from sleeping tonight.

 

Atta Boy!!!

 

Oh... My...God...


As I was driving over to the shop in my Jeep I repeated several times; "I'll be damned if thats what it is"...

Low and behold. I didnt even let her really warm up. Opened the gas cap, choked her, fired her up, only allowing enough warm up time for me to put on my helmet. And off we went. Vroooom! Didn't miss a beat!


You should have seen me out there in my pajama bottoms, some loafers, and two winter jackets on hahahaha

Good thing its after 1am here

Thanx Chacal.. Soo, now what? Aside from spending the 70-80 bux plus for a new(ebay) cap, is there any walkthroughs out there to rectify a bad venting cap?

 

Re: Stuttering.. Thought it was the clutch, now I'm not sure

You can just call me Chacal, like everyone else; let's dispense with these silly formalities....

Huh. Well, you've got all of eternity to look forward to being damned, now! :twisted:

Video?

On second thought: NO.....

We carry brand new caps in stock!

But, you can take yours apart and see if the little vent hole is plugged, and clear it out. OR, it could be equipped, by mistake, with a non-vented (California-spec) cap on it, which would cause these problems.

If you do decide to take it apart, go VERY slow and NOTE CAREFULLY how the latching mechanism operates, and which parts fit where and how. TAKE NOTES OR PHOTO'S AS YOU DIS-ASSEMBLE. Trust me......

While you have it apart, it's not a bad idea to replace the rubber sealing gasket if it is cracked or coming apart in chunks.........we carry those, too!

 

The rubber sealing gasket appears to be stout, and pliable. Although, the splines seem a bit sketchy. They don't retract as smoothly as one would assume. I am lucky enough to have my wife's overly expensive camera to document the disassemble... Dually noted advice, well taken.

I'm just so giddy that the problem was simply due to air fuel exchange in the tank. I was about to order clutch springs, and buff up the plates in between the pressure plates as a last ditch effort. I was at a loss, and had expended my level of expertise. It may have taken me weeks to diagnose this problem on my own after throwing parts at it like a monkey throwing feces at a glass wall...

As far as the video of me riding in my pajamas, that is only instilled in my own memory for the moment. I'm sure that cell memory will be replaced with something more relevant in the near future, only to be resurfaced by a hypnotist in Miami Beach Florida in the far future, as I fight a battle with arthritis, a bad knee, and telling stories fueled by dementia of me being a hells angel.

Thanks again.

 

Lol yall are funny. Veldakin you sound like me runin out to the shed cause "curiosity killed the cat"

 

I LOVE this thread! You guys are a gas! And I totally get the excitement that you must have been feeling when the light bulb came on. Way to go team!

 

Re: Stuttering.. Thought it was the clutch, now I'm not sure

Not so fast. People pay good money to see far worse.

Case in point: Japan.

Probably NSFW - don't say I didn't warn you.

 

Well, after work tonight I decided to grab the gas cap on my home. Astonishingly, it wasn't as hard as I had ascertained. I didn't even need to take pics of the disassemble. However, to my surprise, the PO had apparently decided to use the gas cap when he Kreem coated the tank. I must have pulled/scraped a thimble full of that white nightmare from within the gas cap assembly. After a 10hr shift at work I was far too tired to go back over and put it on for a test run, as I was certain the blockage was due to the kreem gunk.

Update tomorrow...

 

She's all good now. Thnx for the advice chacal. 86f tomorrow, can't wait to go for a nice long ride

 

I just wanted to give a big "THANK YOU!" to chacal on his advice about the gas cap venting. Just wanted to give thanks, where thanks is due. Not only is my bike running good... she is running GREAT! My powerband is back. In full force. Even my wife noticed Maxi's "get up and go" on our last ride since cleaning the gas cap vent.

Poor girl has probly been starving for fuel since the day I bought her.

Hats off to you chacal. Hats off... I am in debt to you my friend. It's still amazes me that something so simple can cause such disarray. My father is a 35 year mechanic for Disney and he always spouts the KISS method. Meaning; Keep It Simple Stupid.

*Edit* Sorry for the triple post.