XT650 brand new - surges

crabby_moto

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Hi,
Just got a husqvarna LC 121FH with a Kohler XT650. Starts right up first pull, then the motor surges up and down, constantly. No throttle control on this model. I cleaned the carb even though it was new, and still happened. So, I bought a brand new carb and carb kit, just put it on and it still happens. Now I'm wondering, are these made this way? Some sort of emission thing, because it seems to be lean? It's really annoying! I have video, but not sure how to post it.
Any help is greatly appreciated!!
 

bertsmobile1

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If it is brand new it has a warranty.
Put the old carb back on and take it back to where you got it from.

And yes idiot EPA regulations means they run way way way too lean then any tiny little thing will make the engine surge
 

crabby_moto

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If it is brand new it has a warranty.
Put the old carb back on and take it back to where you got it from.

And yes idiot EPA regulations means they run way way way too lean then any tiny little thing will make the engine surge

It was on closeout, so no returns unfortunately. Here's a video of it.
Maybe drill out the main jet?
 

bertsmobile1

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Close out = no warranty over there ?
Nest question is did you get the right carb ?
there are a lot of variations in those plastic ( rubbuish ) cabs so I have just found .
And yes that is a typical low fuel surge and quite chronic too I might add.
Also where did you get the replacement carb from ?
there are a lot of defective carbs out there being rejected by Briggs then on sold on the web as "fits" with nothing that says it is good or has been tested.
 

crabby_moto

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I got the carb off of Amazon, it was listed as being correct for this motor. But, there are lots on there listed as being correct. It does bolt on fine, but not sure how to tell if the jets are not correct.
Is there a better website, location to get the correct carb?

Close out = no warranty over there ?
Nest question is did you get the right carb ?
there are a lot of variations in those plastic ( rubbuish ) cabs so I have just found .
And yes that is a typical low fuel surge and quite chronic too I might add.
Also where did you get the replacement carb from ?
there are a lot of defective carbs out there being rejected by Briggs then on sold on the web as "fits" with nothing that says it is good or has been tested.
 

bertsmobile1

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Yes , it is called a mower shop and by prefference a small mower repair shop where they sell used mowers & do repairs.
Surging happens because the engine is not getting enough fuel to sustain the high revs so it slows down .
Then in response to the engine slowing down, the governor relaxes and the throttle opens wide
The sudden gush of air over the carb venturi causes the mix to go slightly rich thus the engine picks up speed then runs out of fuel & slows down again, thus the cycle continues.
So either not enough fuel is geeting mixed into the air by the carburettor or air is entering the engine after the carburettor .

To check for the latter you saturate the manifold with WD 40 or similar with the engine running
If it blows white smoke or changes speed then you have an air leak .

To check for the former you start the engine and put your finger on the governor arm and manually work the throttle, opening it slowly till the engine starts to miss .
If you can hold the throttle open & get the engine to run smoothly then the carb is not putting enough fuel into the engine
 

Rivets

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Whoever said that it has no warranty, because it was on close out is a complete idiot. Both Kohler and Husqvarna use the date of purchase to establish when warranty starts and ends. Another reason to purchase equipment from dealers who know their equipment.
 

crabby_moto

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Whoever said that it has no warranty, because it was on close out is a complete idiot. Both Kohler and Husqvarna use the date of purchase to establish when warranty starts and ends. Another reason to purchase equipment from dealers who know their equipment.


I tried registering the mower on the husqvarna site for the warranty and the web form didn't go have the model listed. Maybe because it was last years model?
 

crabby_moto

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Yes , it is called a mower shop and by prefference a small mower repair shop where they sell used mowers & do repairs.
Surging happens because the engine is not getting enough fuel to sustain the high revs so it slows down .
Then in response to the engine slowing down, the governor relaxes and the throttle opens wide
The sudden gush of air over the carb venturi causes the mix to go slightly rich thus the engine picks up speed then runs out of fuel & slows down again, thus the cycle continues.
So either not enough fuel is geeting mixed into the air by the carburettor or air is entering the engine after the carburettor .

To check for the latter you saturate the manifold with WD 40 or similar with the engine running
If it blows white smoke or changes speed then you have an air leak .

To check for the former you start the engine and put your finger on the governor arm and manually work the throttle, opening it slowly till the engine starts to miss .
If you can hold the throttle open & get the engine to run smoothly then the carb is not putting enough fuel into the engine


Thanks, I'll try these methods out!
 

bertsmobile1

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Post all of the number on your mower.
There are a lot of people on here who are trade so can verify them and verify warranty.
No idea on the USA situation but down here in OZ big retailers will buy heavily discounted remainders from overseas .
In this case the Australian distributor is not liable for warranty but the retailer is .
The retail chains try to con the customers into taking the mower to a mower shop but the mower shop can & will charge normal repair fees as the mower is not under an Australian distributors warranty
I get a few customers every year in this situation. Most times I can convince them to take it back to the retailer after getting a payment confirmation from the credit card company as proof of purchase if they have lost their receipt.
 
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