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Discussion Starter · #1 ·
This is my first post so all kindness and understanding if I don't obey all the customs and step on a toe or two. Please forgive.

The bike will idle with the choke on, but has no power to pull away. If I turn the choke off the engine rpms climb as if to run away then will die completely. The bike is a used bike with 21k on it and has seen some rough service. When I first got the bike, it ran great. I've put 5k on it.

This is what I've done: Pulled the carb's off and taken the bowl bottoms off and blown carb cleaner through the jets. However the bowls were very clean with no accumulation of trash. All the jets were clean and open. I next checked the throttle position switch (TPS) with my ohm meter. Per manual Ohm 1 should measure between 3.5 - 6.5 Ohms; my was 5.0 Ohms. With the throttle full open Ohm 2 reading should be 76% of Ohm 1 reading. I was dead on it at 3.8 Ohms. So now I'm at a loss to as to what to check next.

I have had a knowledgable friend (not a mechanic) who has owned and raced a GSXR, same year, tell me that my cam chain is making too much noise and is either a worn out cam chain/sprockets and/or the cam chain tensioner guides are worn out. I took off the auto cam chain tension adjuster and it seemed ok. It was not stuck and the spring was operable. It did appear to be at about 85% of the total travel distance (kinda a SWAG on my part). Could a worn out timing chain cause an idle problem?
 

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possible but not all that likely.

if you have given the carbs a good clean, I suggest you check for vacume leaks.

especialy if you ever put ethenol gas in it.

another thing to check is ignition timing.
 

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A few questions:
1-Has the bike sat inactive for any extended period of time? (6 months or more)
2-Do you hear the fuel pump come on (prime) when the key is switched on?
3-What has lead up to this poor running condition.
These bikes are notorious for several things including carbs becoming clogged and C.C.T. going bad over time.
It is possible you have a fuel delivery problem and the cleaning method you described is not really one that will get clogged carbs adequately clean where they need to be.
If the fuel pump is not running the bike will idle but die when the demands for more fuel are called for.
If the bike jumped timing because of a worn c.c.t or worn guides & chain, that could contribute to your woes.
From what you have described ("spring was operable") the c.c.t. is defective as there should be no inward movement of the plunger only outward movement allowing for constant pressure on the cam chain guide (slipper)
1st thing I would suggest is to remove the valve cover and timing inspection marks cover and reset the timing and/or replace the c.c.t.
You can also check for all vacuum lines to be properly affixed as previously mentioned, especially the large one in front of the air box.
 

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If/when you have "fixed it" it's always nice to come back here and let us know that you have, what was wrong and if we were of any help.
A please and more importantly, a "thank you" go along way in getting folks to help (i.m.o.)
Remember...Be Kind & Rewind!
 

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Discussion Starter · #5 ·
I am really sorry. I got busy: garbage disposal started leaking, temporary fix with a bucket then the clothes dryer quit heating. The bucket didn't work on it. I do appreciate you taking the time to read and reply with suggestions and I promise to do a better job of giving feedback.

In answer to the post by: Wetbehindthegears:
1. The bike has not set up inactive more than usual. In fact, it had been running well last summer and was ridden every day or so. It began to give problems late in the Fall around the first of November.

2. Fuel pump: Yes. I can hear it when the ignition is turned on. And the bike seems to have full power above 3k rpm or at highway speed.

3. Significant events just prior to problem: My son-in-law has been riding the bike since last spring. I asked him. Just before the problem developed, he dropped the bike. He says loose gravel; I say he got over confident. Anyway, he told me he felt like the problem started right after that.

Vacuum leaks: That was one of the first things I looked for. All lines and connections appeared good. The one thing I have not checked are the piston valve diaphragms for a rupture. I looked at one and it looked great but I did not look at the other three.

CCT: I assume by this you mean the Cam Chain Tensioner? When I said it seems to operate correctly, I meant it springs out freely, then with the turn of a small screw driver I can retract it against the force of the spring. I can then hold it retracted but if I turn it loose it springs out and locks in the out position.

My next plan is the check the cam chain timing, chain, cam sprockets and chain guides. I do have one question: Can the chain guides be replaced without removing the head?

Again I apologize for not getting back sooner. However it is going to be a couple or three weeks before I can get around to working on the bike again. So don't give up hope on me. I will post again as soon as I have information to share. Thanks for your input.
 

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#3 tells me something.
These bikes are ultra sensitive to floats sticking when they get dropped.
It is very possible a float has hung up after the fall.
You can try giving each float bowl a few light taps with a plastic mallet or screw driver handle to dislodge the float should it have become hung up in its float bowl while idling.
Perhaps that will help?
 

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Discussion Starter · #8 ·
Good point about the possible sticking float(s). However I have had the carbs off. Taken the bowl bottoms off, removed the jets and floats, including float needles. I blew everything out with carb cleaner, even though I found no sediment or thrash, then reassembled and replaced the carbs. Idle problem still there.

BTW: As for feeling chastised, I did not take it that way. It was just good friendly advice that I agree with.

I'll post again when I have a chance to check the cam chain timing.
 

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Good point about the possible sticking float(s). However I have had the carbs off. Taken the bowl bottoms off, removed the jets and floats, including float needles. I blew everything out with carb cleaner, even though I found no sediment or thrash, then reassembled and replaced the carbs. Idle problem still there.

BTW: As for feeling chastised, I did not take it that way. It was just good friendly advice that I agree with.

I'll post again when I have a chance to check the cam chain timing.
We anxiously await the outcome...
 

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Discussion Starter · #10 ·
Here's an update:

I finally got around to working on the bike again. Suspecting a cam chain/valve timing problem, I took the valve cover off and checked. The chain was tight and there was no perceptible wear on the cam sprockets, the top slider guide looked good. I checked the timing per the manual and it was dead on. I even checked the valve tappet to cam lobe clearance and it was within limits.
 
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