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Discussion Starter #1
I just can't seem to figure this one out.
To me, I would say it is carb related.

In 1st and 2nd at full throttle, it feeel like fuel starving. It is so erratic. I can gradually up the throttle and get through the gears and when I get to 3 and up, she is fine To get a fast start, I get a major bog on 1 and 2.
Sometimes when I am just sitting there at idle and I get on the throttle, it will bog too.

I bought this quad and it needed some work. I have done a lot to this and it is real close. Just don't know what the previous owner had done to it.

Clean air filter
Pulled the carb apart and really cleaned it.
I am located at approx 6500 feet
the 2 jets I pulled off were a 138 and an 80 Believe the main was 80
She sits at idle just perfect
Also does not seem to have a ton of power. I had a Honda Recon 250 that seemed to be much much more powerful
 

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Discussion Starter #2
Any help on this?
Heres a little more info on this as well.
the main was 138. Not 80, And I can't really read the starter jet. It has a scratch through the number.
The slow jet is 38

Its running very erratic. 1 sec its running normal and then a blip of the throttle and it is revving up high and won't come down.
Took it out one day and as usual bogs at high rpms in 1st 2nd and sometimes 3rd.
End of the day, the battery was very low.
We could push start it and it was fine to get home, but as soon as we shut it off, the starter would barely turn

Things that have been done to it prior to my first start
New top end - new piston, new p rings, new valves, new valve seals
Carb got a good cleaning. Bought a rebuild kit, but the jets looked way bigger than the originals, so I thoroughly cleaned every jet and reused.
Air filter is clean
I have messed with the fuel screw many different ways. Seemed to run better screwed all the way in, but it still was a bad bog.

I can sit in neutral and slowly rev it up with no problems. Once I get higher than I like, I just let off.
I full throttle it quickly and it bogs out.
I can do a video if it helps.
 

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Pull the intake boot off of the carb and partially cover the carb with your hand and play with the throttle and see if that makes any difference. Also make sure that the vacuum operated slide works properly.
 

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Discussion Starter #4
The slide seems to work just fine as it should.
I took the intake boot off and messed with throttle with my hand partially covering and it did not like that. Just kept wanting to die.
What am I trying to do there?
 

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Checking to see if it was running lean. What happens when you run it with the choke on? Did you set the float height to 17 mm? Have you checked it for air leaks?
 

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Discussion Starter #6
I think I have it set to exactly 17mm
Putting the choke on kills it. (when warmed up)
I checked for air leaks and I was getting some around where the intake boot meets the carb. I tightened it up as much as possible.
Now when I spray starting fluid, it does still raise the rpms, but very very little.
Being at high altitude I was told to go lower main jet. When I did that, it made it much worse.
 

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Check the diagphram carefully for cracks rips or tears. Very important that it is seated correctly.

Sent from my SM-G950W using Tapatalk
 

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Seated correctly in the groove ?
 

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Discussion Starter #10
I have taken that part out and installed many times to make sure it is seated properly.
I may try a bigger jet just because I don't know what else to do.
When I have it off again, I will redo the diaphragm.
I just mpied the tank and checked the petcock and those filters and all are good and clean
 

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Read this

 
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Discussion Starter #12
DOes anyone think this could be electrical?
Stator, coil, computer, etc...?

I just put on another carb just to test and it is doing the exact same thing.
 

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Is the other carb jetted the same as your original?

The electronics on the 250/300 usually are quite trouble free. You can download a service manual from countrycat.com and check the electrical system, but I wouldn't start throwing parts at it, especially aftermarket Chinese ones.

Did you do the rebuild or was it already done when you got it? By your first post it sounds like you might have bought it rebuilt. For grins, I would check to make sure the cam is timed properly and the valves are set correctly. Do you see any dampness or oil coming from between the head and cylinder?

I still think you might have an air leak somewhere. I wonder if the o-ring is on the intake flange and the gasket is in good condition?
 

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Discussion Starter #14
Matt193-
Thats a good call.
I should go back through the timing.
I did the rebuild myself.
How would it run if it was off by 1 tooth? It does not backfire

The O-ring on the intake flange. Hmm, not sure where that is. Please explain if you don't mind
 

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Honestly, I've never driven a machine that was out of time but I would think it would run lazy. Granted the Recon you're comparing this to is a lighter machine, your 250 shouldn't be excessively slow.

Take a look at the pic below to see the o-ring and gasket on the intake. You might not have taken that apart, but it could still be leaking.


364491
 

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Discussion Starter #16
SOLVED-
So I was 1 tooth off.
I need to go out an test it, but a shot down the driveway and no bog down.
Thank you all very much. I knew I would get there. Just needed some help getting there
 
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