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Hey guys, I have a K8 750. Quarter throttle, rolls through any rpm, half throttle and up, bogs down. No FI light! Put new air filter, new spark plugs, new fuel filter(one in the pump). Don’t know what else to do. I don’t want to have to put it in the shop. The money is the hard part. I’ve tried sea foam, never ran any gas under 93 octane. Ove been through 3 tanks to make sure it’s not bad gas.
 

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Welcome.

Easy thing first. Lift the tank and carefully watch the fuel hose as you lower it back down. If one of the fittings (I can't remember which) is not positioned properly, the fuel hose will kink.

Otherwise, your issue sounds like a fuel problem. The next step would be to do a fuel pressure and volume check per the service manual.
 

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Discussion Starter #3
Welcome.

Easy thing first. Lift the tank and carefully watch the fuel hose as you lower it back down. If one of the fittings (I can't remember which) is not positioned properly, the fuel hose will kink.

Otherwise, your issue sounds like a fuel problem. The next step would be to do a fuel pressure and volume check per the service manual.
The line was kinking, I got it to stop kinking. Still acting up. I don’t have a pressure gauge to test the fuel pressure sadly...
 

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The line was kinking, I got it to stop kinking. Still acting up. I don’t have a pressure gauge to test the fuel pressure sadly...
They are pretty cheap at Harbor Freight or you can borrow one at many of the chain auto supply stores.
 

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Some options:
Fuel pressure check is good (as stated by rv6john)
Have you ever had the exhaust valve adusted (if stock exhaust)? The cables can get loose and will not allow the buttery to fully open.
Do you have a power commander or bazzaz on it? Bad map/too much fuel.
Any colored smoke coming out of the exhaust?
How does it idle/sound when idling?
Could also be STVA failing (not really a factor for bikes 2006 and newer but I had my 2011 GSXR 1000s' fail so its a possibility and it failed closed (top speed limitied to 89mph in all gears)).
 

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"new fuel filter(one in the pump)" and "The money is the hard part."
That sounds like you replaced the strainer (~$20) instead of the real filter (~$120). A pressure gauge is the ultimate test and you can get one on ebay (0 - 60 psi) for under $5. You'll also need some hose and fittings. But you'll probably be fine doing a flow test as described in the service manual. Bogging is very commonly associated with a clogged main filter.

I guess the injectors could be clogged, the EXCV isn't opening, or the cat has failed. But I'll bet it's the filter.
 

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"new fuel filter(one in the pump)" and "The money is the hard part."
That sounds like you replaced the strainer (~$20) instead of the real filter (~$120). A pressure gauge is the ultimate test and you can get one on ebay (0 - 60 psi) for under $5. You'll also need some hose and fittings. But you'll probably be fine doing a flow test as described in the service manual. Bogging is very commonly associated with a clogged main filter.

I guess the injectors could be clogged, the EXCV isn't opening, or the cat has failed. But I'll bet it's the filter.
@billv do you know for sure that there Is a high pressure filter in #12?

I know there is on the K6/K7 where it is labeled as a fuel filter whereas on the K8 #12 is labeled as a regulator. I've never had anyone give me a definitive answer.

293194
 

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^I'm sure. I happen to have the K8 750 service manual and it's referred to there as the fuel filter cartridge. It includes a pressure regulator, which for reasons unknown to me is never supposed to be removed from the cartridge and Suzuki likes to call the whole assembly a regulator. Don't know when they changed but that pump looks like the newer T35 type. Their filters all look the same. That #11 strainer is referred to as a fuel mesh filter in the manual. Another way to look at it is that an injected system needs a 10 micron filter somewhere and that certainly isn't the strainer. Also see page 2 here.
 

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Discussion Starter #9
I ended up putting it in the shop. Turns out my gas line kinked itself when I put the tank down... pressure is perfect from the pump and volume, but out of the line, it’s not at all lol. They r also fixing my neutral sensor, and a couple other things
 
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