SV650 Bogging down upon quick throttle response - SV650.org

Redrose · 01-01-20, 04:52 PM

So I washed the bike and then got this issue, so my initial guess is that it's electrical. It's also an 09.

When I turn the bike on, all is as normal. I turn the key, the go to start it, to which it just about starts up (but i think my battery needs some juice, will put it on the tender tonight) and then idles totally fine, as usual. If I slowly add throttle, it's fine. But if I wack on some throttle with any speed. It seems to bog or will stall.

Also, it appears as if the STVA moves very jerkily and delayed to the action of the throttle. I think it's the STVA anyway. It's the bar that's the upper out of the two if that makes sense.

Also, when I turn it off, I get a weird ratchet/clicking like noise coming from below the airbox, maybe on the right hand side?

Also, any ideas if this will affect MOT? I have it in 2 days...

(Links to videos to follow soon!)

Seeker · 01-01-20, 05:24 PM

The purpose of the secondary throttle valves is to maintain a constant airflow through the inlet manifold. If they're not working correctly a sudden opening of the throttle may (will?) cause bogging. The secondary throttle valves should move smoothly - maybe the linkage needs cleaning and/or lubricating or electrical connections to STV needs spraying with ACF50

Any c28 errors?

Here's an 09 SV video showing their dance: https://www.youtube.com/watch?v=2dkXIIf7U20

Redrose · 01-01-20, 06:27 PM

Quote:

Originally Posted by Seeker

The purpose of the secondary throttle valves is to maintain a constant airflow through the inlet manifold. If they're not working correctly a sudden opening of the throttle may (will?) cause bogging. The secondary throttle valves should move smoothly - maybe the linkage needs cleaning and/or lubricating or electrical connections to STV needs spraying with ACF50

Any c28 errors?

Here's an 09 SV video showing their dance: https://www.youtube.com/watch?v=2dkXIIf7U20

Thanks for the reply. I will take off the airbox then and have a look. And by linkage, I presume you mean the plastic ends which connect to each side? Do you think I would be able to test whether or not it is this which is causing my issue by either removing the connector that operates them so they're not being operated by the ECM and just hold, with my fingers, wide open while I rev the bike?

Redrose · 01-01-20, 06:33 PM

And no error codes. Just _ C00

Adam Ef · 01-01-20, 06:56 PM

You haven't got water in the front spark plug have you? Sounds like one cyclinder could be flooding flooding when opening the throttle, maybe due to a lack of a spark in the front cyclinder. It's possible for a bike to run with a cyclinder down but the ECU still to be adding fuel as if all is normal.

Redrose · 01-01-20, 06:58 PM

Quote:

Originally Posted by Adam Ef

You haven't got water in the front spark plug have you? Sounds like one cyclinder could be flooding flooding when opening the throttle, maybe due to a lack of a spark in the front cyclinder. It's possible for a bike to run with a cyclinder down but the ECU still to be adding fuel as if all is normal.

How will I know or how can I test if that’s the case?

Adam Ef · 01-01-20, 07:03 PM

Pull the front plug. You'll have to unbolt the rad a bit to lean it out of the way. It's a quick thing to do to rule it out if it's not the problem. Is there a drain hole on the front cyclinder? Sometimes those get blocked up too.

I only mention it as a possibility as you stated the last thing you did to change anything was wash the bike. The other symptons don't sound like a spark problem. They may be coincidence now you're looking for something though.

Adam Ef · 01-01-20, 07:05 PM

+ Does the front cyclinder / exhaust header get hot? Spray water on it to see... don't touch it!
Have you had the bike running long enough to get up to temperature or managed to ride it?

DJ123 · 01-01-20, 07:08 PM

it may be your airbox is not sealed on to the throttle bodies (the rattling you're hearing). And it's bogging down due to the flood of air coming in it can't measure.
Check the airbox is securely fastened down.

SV650rules · 01-01-20, 07:08 PM

If it is the twin spark engine I am not sure how water in one of the plug recesses would affect it. Sounds like throttle body, but how washing it would affect that I don't know unless water has got into sensors, how high pressure was the hose you used ?

01-01-20, 04:52 PM	#1
Redrose Junior Member Join Date: Dec 2019 Posts: 14	SV650 Bogging down upon quick throttle response So I washed the bike and then got this issue, so my initial guess is that it's electrical. It's also an 09. When I turn the bike on, all is as normal. I turn the key, the go to start it, to which it just about starts up (but i think my battery needs some juice, will put it on the tender tonight) and then idles totally fine, as usual. If I slowly add throttle, it's fine. But if I wack on some throttle with any speed. It seems to bog or will stall. Also, it appears as if the STVA moves very jerkily and delayed to the action of the throttle. I think it's the STVA anyway. It's the bar that's the upper out of the two if that makes sense. Also, when I turn it off, I get a weird ratchet/clicking like noise coming from below the airbox, maybe on the right hand side? Also, any ideas if this will affect MOT? I have it in 2 days... (Links to videos to follow soon!) Last edited by Redrose; 01-01-20 at 04:54 PM. Reason: Updated bike info

01-01-20, 05:24 PM	#2
Seeker Member Mega Poster Join Date: Jun 2016 Location: NE Lincs Posts: 1,069	Re: SV650 Bogging down upon quick throttle response The purpose of the secondary throttle valves is to maintain a constant airflow through the inlet manifold. If they're not working correctly a sudden opening of the throttle may (will?) cause bogging. The secondary throttle valves should move smoothly - maybe the linkage needs cleaning and/or lubricating or electrical connections to STV needs spraying with ACF50 Any c28 errors? Here's an 09 SV video showing their dance: https://www.youtube.com/watch?v=2dkXIIf7U20 __________________ 2016 SV650AL7 2023 GSX-8S

01-01-20, 06:33 PM	#4
Redrose Junior Member Join Date: Dec 2019 Posts: 14	Re: SV650 Bogging down upon quick throttle response And no error codes. Just _ C00

01-01-20, 06:56 PM	#5
Adam Ef Member Mega Poster Join Date: Dec 2015 Location: Bristol Posts: 1,200	Re: SV650 Bogging down upon quick throttle response You haven't got water in the front spark plug have you? Sounds like one cyclinder could be flooding flooding when opening the throttle, maybe due to a lack of a spark in the front cyclinder. It's possible for a bike to run with a cyclinder down but the ECU still to be adding fuel as if all is normal. __________________ >>> ? <<< Past: Street Triple 765rs, DRZ400s,GSXR1000 K9, VFR800 A8, ZX6R 636 2006, CRF250L, GSXR750 K7, VFR800 A7, GSXR750 L3, Street Triple 675R, MT09 Tracer, SV650s K8, CB250rsd, YBR125...

01-01-20, 07:03 PM	#7
Adam Ef Member Mega Poster Join Date: Dec 2015 Location: Bristol Posts: 1,200	Re: SV650 Bogging down upon quick throttle response Pull the front plug. You'll have to unbolt the rad a bit to lean it out of the way. It's a quick thing to do to rule it out if it's not the problem. Is there a drain hole on the front cyclinder? Sometimes those get blocked up too. I only mention it as a possibility as you stated the last thing you did to change anything was wash the bike. The other symptons don't sound like a spark problem. They may be coincidence now you're looking for something though. __________________ >>> ? <<< Past: Street Triple 765rs, DRZ400s,GSXR1000 K9, VFR800 A8, ZX6R 636 2006, CRF250L, GSXR750 K7, VFR800 A7, GSXR750 L3, Street Triple 675R, MT09 Tracer, SV650s K8, CB250rsd, YBR125...

01-01-20, 07:05 PM	#8
Adam Ef Member Mega Poster Join Date: Dec 2015 Location: Bristol Posts: 1,200	Re: SV650 Bogging down upon quick throttle response + Does the front cyclinder / exhaust header get hot? Spray water on it to see... don't touch it! Have you had the bike running long enough to get up to temperature or managed to ride it? __________________ >>> ? <<< Past: Street Triple 765rs, DRZ400s,GSXR1000 K9, VFR800 A8, ZX6R 636 2006, CRF250L, GSXR750 K7, VFR800 A7, GSXR750 L3, Street Triple 675R, MT09 Tracer, SV650s K8, CB250rsd, YBR125...

01-01-20, 07:08 PM	#9
DJ123 Member Mega Poster Join Date: Jul 2011 Location: Somewhere over there Posts: 3,245	Re: SV650 Bogging down upon quick throttle response it may be your airbox is not sealed on to the throttle bodies (the rattling you're hearing). And it's bogging down due to the flood of air coming in it can't measure. Check the airbox is securely fastened down. __________________ BMW F800ST

01-01-20, 07:08 PM	#10
SV650rules Member Mega Poster Join Date: Nov 2016 Location: Shropshire UK Posts: 1,363	Re: SV650 Bogging down upon quick throttle response If it is the twin spark engine I am not sure how water in one of the plug recesses would affect it. Sounds like throttle body, but how washing it would affect that I don't know unless water has got into sensors, how high pressure was the hose you used ? __________________ 2016 SV650 AL7 Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Unusual Throttle Response	enzoalex	SV Talk, Tuning & Tweaking	24	17-06-11 10:21 PM
Throttle Response slooooowwwwwww	plowsie	Bikes - Talk & Issues	59	02-03-08 07:06 PM
Jerky Throttle Response	I'm_a_Newbie	SV Talk, Tuning & Tweaking	7	17-10-06 09:47 AM
throttle response	Londonoz	SV Talk, Tuning & Tweaking	8	19-07-05 06:24 AM
Throttle response	kavana77	SV Talk, Tuning & Tweaking	8	04-04-05 07:50 PM