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Discussion Starter #1
Hey everyone. I'm looking for some help on this particular problem. It seems very unique and uncommon because I can't find any other topics on it, whether vstar or any other bike. Basically bought this bike a few months ago and it runs amazing, except for one little flaw I noticed. If I drive the bike on the highway for over 20 minutes, then park the bike and go to start it again within 10 minutes, I get aloud TOC! noise coming from the engine on startup. I'm thinking starter clutch maybe, but I'm really really unsure on what this is. This never happens when just riding around town, or on cold starts. Only after riding the bike on the highway for awhile.

Work done on the bike so since June:
-Acquired Bike and noticed it ran a little lean
-Replaced K&N air filter with Stock, bringing air/fuel mixture back to normal
-Oil+Oil filter change
-Spark plugs changed
-Brake fluid flushed (Front and Back).
-Carburetor boots surface cracked. Sealed with High Temp Rubber Adhesive
-Carburetors taken apart and cleaned (clogged pilot jets)
-Carburetors synced
-Idle adjusted to 950-1050 RPM
-Fuel completely drained and replaced with fresh fuel
-Air Induction System removed
-Final drive oil changed

Here's a video on it. It might be hard to hear if you're listening on a cell phone, but basically you'll hear a TOC or CRACK noise right when my bike starts.

 

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you lost me at TOC

?!

do you turn the petcock off when you park the bike?

if so, the float bowls may be boiling empty from the hot engine while it sits, you turn everything on, the floats are not full yet, engine starts up super lean?
 

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Discussion Starter #3
The best way to describe the noise is it sounds like a loud TOC!! ...hard to describe...

I don't turn off the petcock when i park the bike.
 

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toc whatever that is... it sounds like a clunk aka kickback usually heard on startup and shut down. check the tps adjustment.i checked mine over the weekend and it was waay out of spec. i ordered one from partzilla $163.00, hope i made a correct decision.
 

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something you did not mention

are you giving it any gas while starting it, hot... cold..choked.. ever?

dont know if you are aware, that is a known issue with the 1100 - if you give it gas while the starter is engaged it will back spin the starter clutch, and if you keep doing it the starter clutch will break.
 

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something you did not mention

are you giving it any gas while starting it, hot... cold..choked.. ever?

dont know if you are aware, that is a known issue with the 1100 - if you give it gas while the starter is engaged it will back spin the starter clutch, and if you keep doing it the starter clutch will break.
And just to add to this, giving it throttle while starting does absolutely nothing to help it start better.
 

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Discussion Starter #7
toc whatever that is... it sounds like a clunk aka kickback usually heard on startup and shut down. check the tps adjustment.i checked mine over the weekend and it was waay out of spec. i ordered one from partzilla $163.00, hope i made a correct decision.
thank you, i will look into the tps adjustment since thats one bridge i have yet to cross.
 

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Discussion Starter #8
NortherRider, KCW, I have given throttle when starting it a few times when I first acquired the bike but quickly learned from the forum and the knowledge base that it's bad news for the starter clutch and have not done it since. But I'm sure the past owner has done it in the previous 41,000 kms of owning the bike so maybe that noise is my starter clutch acting up when its hot?
 

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Discussion Starter #9
Only thing I don't get, is if its the TPS, why is it only doing it when the bike is hot from a highway commute.
 

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Look at poor attempt of a diagram below. Red arrows point to internal TPS contacts. The position sensor has a variable resistance potentiometer (or contact points, depending on model) that sends out varying voltage signals. When the contact points get worn the resistance is inaccurate. These are metal contacts and metal expands with heat also causing readings out of range. The blue shows that the internal sensor movement. I've rewritten this several time and can not come up with easier way to explain it. Come to my house and with my meter I can illustrate very easily. 😁 Hope this helps a little, if not google how to test TPS sensor for possible better explanation.

 

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Discussion Starter #11
Look at poor attempt of a diagram below. Red arrows point to internal TPS contacts. The position sensor has a variable resistance potentiometer (or contact points, depending on model) that sends out varying voltage signals. When the contact points get worn the resistance is inaccurate. These are metal contacts and metal expands with heat also causing readings out of range. The blue shows that the internal sensor movement. I've rewritten this several time and can not come up with easier way to explain it. Come to my house and with my meter I can illustrate very easily. 😁 Hope this helps a little, if not google how to test TPS sensor for possible better explanation.


Thank you that actually makes sense. Lol. I'd like to test my TPS sensor with a multimeter. I googled different sites but don't quite understand. My understanding is I unplug the TPS sensor at the front cylinder side, and test the 3 prongs in the connection. But I'm lost after that. I don't know which colors to test. I don't know the correct numbers they should be set to. I don't know how to adjust the sensor to try to reach that number.

The bike runs perfect except when starting so the issue with the TPS would be closed throttle I'm assuming. Can you give me an idea as to how to test the sensor for closed throttle, and what it should be set to, and how to set it?

I swear I researched it but couldn't find anything that made sense or gave me the specs they should be set to.....
 

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Discussion Starter #13
Since if the TPS is only faulting out when it's hot, it will probably give me the correct values when I test it when it's cold and throw me off.
 

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Since if the TPS is only faulting out when it's hot, it will probably give me the correct values when I test it when it's cold and throw me off.
Have everything ready and test at home after a nice ride.
 

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Discussion Starter #16
Lol that's Chinese to me. Throw me a network firewall and I'll have it configured in 5 minutes. Ask me to test electrical and I'm absolutely lost.

If I buy the part and replace it, is it just a straight unscrew old part, screw in new part? Or would I have to turn the new sensor as well to obtain the correct values.
 

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Discussion Starter #18
Thank you. I tested the wires. I think I see the issue. The TPS is holding on to the closed throttle number for too long. If I open the throttle, then close it, closed now shows a reading of 900, and very very slowly goes back down to lower 800s. A correctly working TPS should return the closed throttle number down right away right? It's been 8 minutes now and it's still showing a reading of 861. (Should be between 560 and 840). The initial closed throttle number was 790.
 

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If it was mine I would double check the readings, then moan as I was entering my credit card number to buy a new one.
 

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Discussion Starter #20
If it was mine I would double check the readings, then moan as I was entering my credit card number to buy a new one.
I triple checked. It's now at 839. Lol...but am I right? Should the number go back down to normal range quicker, on a properly working TPS??

Also what kind of screwdriver do I need to buy to get these tps screws off?
 
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