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Newly Purchased Superhawk running rough

Old 08-08-2011, 10:19 AM
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Newly Purchased Superhawk running rough

Hi. I recently acquired a 1998 VTR1000 with 30K. There is a wicked hesitation/bog/flat spot/surge going on around 4000 rpm that is noticeable at a steady cruise and annoying on acceleration. I replaced the spark plugs and air filter with no improvement. The previous owner thought the valves needed adjustment but I am struggling to understand how that might contribute. I have hesitated to go much further without some thoughts from the experts.

Should I start with the carbs? I think they have been re-jetted but I am not positive.

Thansk
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Old 08-08-2011, 10:35 AM
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Probably need different pilot jets, shim needles, sync carbs. Check this out.

https://www.superhawkforum.com/forum...-set-up-24769/
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Old 08-08-2011, 10:44 AM
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Start with cleaning them, though. What airfilter did you replace yours with?
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Old 08-08-2011, 10:53 AM
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Originally Posted by Vegiepower View Post
Hi. I recently acquired a 1998 VTR1000 with 30K. There is a wicked hesitation/bog/flat spot/surge going on around 4000 rpm that is noticeable at a steady cruise and annoying on acceleration. I replaced the spark plugs and air filter with no improvement. The previous owner thought the valves needed adjustment but I am struggling to understand how that might contribute. I have hesitated to go much further without some thoughts from the experts.

Should I start with the carbs? I think they have been re-jetted but I am not positive.

Thansk
Torie
The carbs may indeed need looking into, but making wholesale changes right off the bat is not a good idea. A rundown of all mods done to the bike (jets, airfilter, exhaust) will help forum members help you out.
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Old 08-08-2011, 11:09 AM
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I will try to find out the mods from the previous owner and post back. Thanks for the quick replies. I have a K&N on it and have an extra one for sale if anyone is interested.

Torie
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Old 08-08-2011, 11:17 AM
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K&N filter is tricky with this bike... to start tuning you may want to get a stock filter and save yourself a lot of headache.

Like killer said, see what you have in there first before making huge changes... a good carb cleaning will tell you the condition of them as well as what you're running so you have something to go off of.

Last edited by 7moore7; 08-08-2011 at 11:19 AM.
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Old 08-08-2011, 11:31 AM
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Toss the K&N, throw in a stock filter, sync the carbs and report back.
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Old 08-08-2011, 11:49 AM
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Originally Posted by killer5280 View Post
Toss the K&N, throw in a stock filter, sync the carbs and report back.
+1
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Old 08-08-2011, 12:25 PM
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hmmm..I guess I will see if I can find a stock one from the dealer....

Likely a dumb question but....how I do I sync the carbs? As per manual?
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Old 08-08-2011, 12:42 PM
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Old 08-08-2011, 12:49 PM
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Originally Posted by ruajohnson View Post
Good place to start! There are a couple of tricks that aren't mentioned on that site too:

First time carb sync will take you a little bit of time to get everything setup. Your end goal is to get the vacuum signal from both cylinders to be equal.

In a nutshell, you can either buy a carb sync tool ($80) or make one ($5), you will probably want to get a boost joint for your front cylinder (part #16214-MB0-000), something to cap it off with, and a t-splitter connection for your petcock vacuum hose as seen on superhawk996.net.

Example of a home-made carb sync tool:
$1.55 Carb Sync Tool by Marty Ignazito
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Old 08-08-2011, 01:58 PM
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I would just try installing a stock filter first, then see how it runs. Next I'd pull the carbs and do a good cleaning, the pilot jets tend to clog up. Then I'd do the sync, if it's still not running right.
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Old 08-08-2011, 02:10 PM
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Well I can see I'm not needed here......
You guys have it covered.....

Carry On.....
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Old 08-08-2011, 02:37 PM
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Originally Posted by 8541Hawk View Post
Well I can see I'm not needed here......
You guys have it covered.....

Carry On.....
What gearing should he run?
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Old 08-08-2011, 02:44 PM
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Originally Posted by killer5280 View Post
What gearing should he run?
OOOOH!
OOOOOHHHHH!
I've got this one!

16/43

That way he can keep most of his top end, yet still have ***** to the wall Acceleration!

hahahahaha
Sorry Hawk
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Old 08-08-2011, 04:27 PM
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Originally Posted by 8541Hawk View Post
Well I can see I'm not needed here......
You guys have it covered.....

Carry On.....
No problemo.
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Old 08-08-2011, 06:14 PM
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Just an FYI. I have a K&N on my VTR with Jardine round High Mounts. It runs fine. I have stock pilot jets, and 185-188 jets. IIRC, I have my bike set up the exact same way as the guy from superhawk996.net has his, and it runs just fine with the K&N.

Before buying a stock filter, try his settings and see how you like it. It's not that hard to get a K&N to work on our bikes.
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Old 08-08-2011, 06:46 PM
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Originally Posted by msethhunter View Post
Just an FYI. I have a K&N on my VTR with Jardine round High Mounts. It runs fine. I have stock pilot jets, and 185-188 jets. IIRC, I have my bike set up the exact same way as the guy from superhawk996.net has his, and it runs just fine with the K&N.

Before buying a stock filter, try his settings and see how you like it. It's not that hard to get a K&N to work on our bikes.
K&N's typically work fine with stock jetting, it's only when you start to tinker with the carbs do you feel the full effect of how garbage they can be on the VTR. I ran with one for over 15K with stock jetting and Vance & Hines pipes, but as soon as I jetted my carbs, my performance when down the toilet. Especially when I added the D&D's. It had the acceleration of a wheelbarrow with a flat tire full of cinderbocks going uphill. I swapped to a BMC filter though as opposed back to stock, and now my performance is through the roof. I love it, and I'm not going back to K&N for this bike.

If you run it stock, K&N is the cost effective way to go, especially since they clean so easy. But if you want more power, burn that damn airfilter.
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Old 08-08-2011, 06:57 PM
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Originally Posted by msethhunter View Post
Just an FYI. I have a K&N on my VTR with Jardine round High Mounts. It runs fine. I have stock pilot jets, and 185-188 jets. IIRC, I have my bike set up the exact same way as the guy from superhawk996.net has his, and it runs just fine with the K&N.

Before buying a stock filter, try his settings and see how you like it. It's not that hard to get a K&N to work on our bikes.
This is true, although many people on here have fixed his problems just by switching the filter... and that's all. It's not a 100% guarantee, and the K&N does work for many people, but there's a good chance that it will fix the problems.

From my own experience, I ran both, tried to tune for both, only had a seat of the pans run to go off of but the stock filter is easily what I chose to run. My ex-mechanic swore by the K&N, actually wouldn't even listen to me when I suggested that the stock filter runs better, and so I tried it again, only to have the same results (dead in the middle of the rev range). I modified the K&N to have the same air dam as the stock, and it still was running too rich. I wanted to get the K&N to work... Even for the vain reason to add it to my list of mods haha....

I'm just suggesting that general advice for someone having issues with carbs is to start with the stock filter... It's just taking one of the unknown's out of the equation. The only people who seem to really draw major benefit from the K&N are those with heavy engine mods....
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Old 08-08-2011, 08:46 PM
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All I can say is that I installed a K&N on my '78 CX500, which already had 2 into 1 exhaust, almost 30 years ago, and I got a big hole in the midrange. The top end was better, but I ditched the K&N a couple of weeks later and went back to stock for the remaining 4 years and 40,000 miles that I owned that bike.

Of course if you're racing on the track, that's a different deal. The time spent dialing it in may be worth it. But on the street I'll stick with an OEM air filter.
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Old 08-09-2011, 07:34 AM
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Originally Posted by msethhunter View Post
Just an FYI. I have a K&N on my VTR with Jardine round High Mounts. It runs fine. I have stock pilot jets, and 185-188 jets. IIRC, I have my bike set up the exact same way as the guy from superhawk996.net has his, and it runs just fine with the K&N.

Before buying a stock filter, try his settings and see how you like it. It's not that hard to get a K&N to work on our bikes.
When you can post two dynoruns of your bike, one with the setup you have now, and one with the only change being the OEM filter and show me the improvement from OEM to K&N your recommendation is valid...

Until that time, the recommendation to NOT expect a gain from using the K&N still stands... Yes, it can be used as a drop in replacement for the OEM filter... But unless the stock filter is severely clogged, the power will either drop or at best remain the same when you swap to the K&N... Simple as that... My money is on a power drop 3k-5k and a smaller (than the drop) gain from 7k to redline... Making the net change a loss, since the midrange is far more usable and important on the VTR than the topend...

Yes, it's hard to get the K&N to work efficiently on our bikes, I can prove that statement... I doubt you can prove yours...
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Old 08-09-2011, 10:23 AM
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Originally Posted by Tweety View Post
When you can post two dynoruns of your bike, one with the setup you have now, and one with the only change being the OEM filter and show me the improvement from OEM to K&N your recommendation is valid...

Until that time, the recommendation to NOT expect a gain from using the K&N still stands... Yes, it can be used as a drop in replacement for the OEM filter... But unless the stock filter is severely clogged, the power will either drop or at best remain the same when you swap to the K&N... Simple as that... My money is on a power drop 3k-5k and a smaller (than the drop) gain from 7k to redline... Making the net change a loss, since the midrange is far more usable and important on the VTR than the topend...

Yes, it's hard to get the K&N to work efficiently on our bikes, I can prove that statement... I doubt you can prove yours...

I knew you would come along and straighten this out. In defense of msethhunter I think he meant that it's not that hard to get our bikes to carburet reasonably well (without giant flat spots and surging) with a K&N and proper jetting, although I suppose that is still debatable. I don't think he was suggesting that a K&N improves performance.
My brief experience led me to put the K&N in a box where it still sits, lonely and neglected.
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Old 08-09-2011, 03:52 PM
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Originally Posted by killer5280 View Post
I knew you would come along and straighten this out. In defense of msethhunter I think he meant that it's not that hard to get our bikes to carburet reasonably well (without giant flat spots and surging) with a K&N and proper jetting, although I suppose that is still debatable. I don't think he was suggesting that a K&N improves performance.
My brief experience led me to put the K&N in a box where it still sits, lonely and neglected.
Well... If I "set it straight" or not is debatable... It's still partially based on opinion that I dislike the K&N, even though it's supported by facts...

The thing that however irks me with the half a dozen or so guys that keep either recommending the K&N and/or saying "it's fine/has worked good for me", have one thing in common... They have at one time swapped to the K&N, made a half-decent setup and never looked back... And none of them have compared to a new and fresh OEM filter at that point...

And all of them give the rather subjective answer "I got it running good!", as in they have no blatant flatspots or surging... But it's fairly obvious that "good enough" seems fantastic if you are used to it... Up until the point where you swap in a fresh OEM filter and discover the difference it makes with a meaty midrange and the effect it has on fuel/mileage... Then "good enough" seems rather useless...

I have done back to back testing, on road and on a dyno... I have the A/F and hp figures to compare... I have spent more time than I care to remeber trying to get the darned thing to work, not believing that K&N could produce something that gave this bad realworld results, and be happy to sell it..

But at some point it become rather obvious to mee that the K&N produces either a rich condition in the larger part of the range and baseline in a small OR baseline in the larger part and lean in a small, and never ever balances out to close to baseline all over, no matter what tricks you try to compensate...

So, it's at best a second rate washable replacement filter if you have an otherwise bone stock bike, at a ridiculously high price... At worst useless... My opinion is well known...
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Old 08-12-2011, 09:30 PM
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Picked up a stock air filter today. $79.99!!!! I see you guys in the US can get them for like half that. Sheesh...that's almost as much as the K&N I just bought which is now not recommended. I will install the filter and sync the carbs and report back!

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Old 08-29-2011, 10:14 PM
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Sorry for the LONG delay.

Okay, I installed the stock filter and it has definetely improved the situation at least in the 4-5K RPM range. I will sync the carbs next and then look at cleaning and then jetting them.

Torie
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