PERFORMANCE

[Theodio]

Gday!!

I'm trying to solve some matters with my newbought bike! As I solved backfiring by exhaust and carbs, by connecting a tube under the fuel tank,

the backiring comes rarely. But it still has poor performance especially high (above 6-7k) it puts a lot of effort. My VTR has K&N filter and motoriwaki ZERO exhausts. Im guessing that the carb needles are stock.

Any ideas?? Aaahhh carbs been synchronized

[VTRDark]

Well above 6-7k wide open throttle will be on the main jets. If you bike has a K&N then there is a good chance someone has also put a dynojet kit in too. You may even have an extra hole drilled out in the slides as per the dynojet instructions which also coincides with this noise you having. The extra hole does not help with these bikes.

You wont know until you strip the carbs down to investigate. Have a good read through the following threads.
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=14214

http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=28922

And then it's time to remove the carbs, open them up and have a tinker. It would at least be helpful to know what the setup is to begin with.

Either that or it's time to get the bike on the dyno and get the dynotech to tinker with them, but this wont be cheap and not many dynotechs like or even know how to work with carbs these days. I suggest you have a play with them first, get to know your carbs and what does what. Get things as close as you can by feel, real world road test, then once your happy do a single dyno run to see how accurate you have tuned things and go from there to fine tune.

It may sound a bit scary removing the carbs and changing things but it's really not too difficult if you competent with the spanners. Once you have done it a few times it gets easier and you will wonder what all the fuss is about with working on carbs. These carbs are very basic and easy to work with. If you get stuck with anything we are always here to help.

(:-})

[lloydie]

Or the timing could be 180 out !
Get it on a Dyno that will show what's wrong

Pink is good red Is leaking exhaust and the blue one is timed 180' out but tuned to pull through 7k
Green is 180' out and won't rev through

[VTRDark]

poor performance especially high (above 6-7k) it puts a lot of effort.

Is this something you have only noticed since the head gasket was replaced?

(:-})

[leevtr]

Gday!!

I'm trying to solve some matters with my newbought bike! As I solved backfiring by exhaust and carbs, by connecting a tube under the fuel tank,

the backiring comes rarely. But it still has poor performance especially high (above 6-7k) it puts a lot of effort. My VTR has K&N filter and motoriwaki ZERO exhausts. Im guessing that the carb needles are stock.

Any ideas?? Aaahhh carbs been synchronized

Get rid of the k&n filter before you do anything...IMO they're sh1t on storms.

[Theodio]

Thank you again for your help!!

I'm skeptic about the timing... I didn't think that! Becouse after the mechanic did the valve clearance she was more smooth but she couldnt rev more quickly as before. But, in low rpm she was riding better. I don't know what he did but I'm thinking he did something wrong because of the noise I heard afterwards. I think that the noise are the valves or the tiny things above the valves (Im not familiar with the english term sorry ) As for the carbs, I'll strip them out and adjust the needles and see whats going on.I like this bike because I love diging through her, adjusting fixing! And if the result is good, the reward is priceless!!! Thank you again you all!!

Greetings!!

[Theodio]

Sorry I forgot! The high rev issue was before the service! If I get her on the dyno, I'd guess 65 bhp at 7000. The bike doesn't pull as a 1000 cc bike. She pulls like a 650 V2 with 1000 cc bike torque response!

[Wicky]

+1

Or the timing could be 180 out !

If you missed it in your previous thread, I'll say it again

The VTR1000F Honda service manual with all specs and procedures is available as a downloadable & searchable PDF in the workshop knowledgebase.

Sounds like you need to go over the bike thoroughly yourself as its the only way to be sure the work done by mechanics has been done properly.

[VTRDark]

mechanic did the valve clearance she was more smooth but she couldnt rev more quickly as before. But, in low rpm she was riding better.

If timing is 180 degrees out then a side effect of this is more power at bottom end at the sacrifice of top end. When you get to 7000rpm does the bike bog down as if there is fuel starvation, so bike stutters a bit and struggles to get the revs higher and moves higher up the revs slowly?

(:-})

[Theodio]

Good day!

If timing is 180 degrees out then a side effect of this is more power at bottom end at the sacrifice of top end. When you get to 7000rpm does the bike bog down as if there is fuel starvation, so bike stutters a bit and struggles to get the revs higher and moves higher up the revs slowly?

Exactly what is going on!! Torque at low rpm and through 6-7k then the bike struggles to redline

[agentpineapple]

classic symptoms of 180 degree's out, I should know....
your bike will feel very strong up to 6k, then struggle, the carbs can be tinkered with to get around the problem, meaning it will redline smoothly but this is just masking over the problem.
i'd check your timing asap.......

[Theodio]

when it passes 5k pulls very strongly til 7-7500.but after, it revs through 10k very flat- slow. I don't know if that is the case. Maybe Wicky is right. Maybe I have to:

-strip the carbs and claean-ajust needles
-put them back in and sychronize and pilo screw them
-remove head covers and see what is oing on wih the timing according the service manual.

I'm not confident about these works even I'm a Mechanical Engineer. I think Saturday morning I'll get it done

[VTRDark]

remove head covers and see what is oing on wih the timing according the service manual.

This will be the one, but you only need to remove the rear cover to put the timing back to as it should. This does sound like a timing issue and it can only be done if cams are removed and the crank is turned over mixing things up. Hence the reason I asked if this only started after having the head gasket replaced.

Read the following post as to how to correct the timing.
http://www.vtr1000.org/phpBB3/viewtopic ... ut#p259219

(:-})

[Pete.L]

I'm thinking timing too but another quick easy thing to check would be the Petcock diaphram.
It could be a bit of fuel starvation, also make sure the vacuum hose is on the right connector.

Pete.l

[jonjonsocal]

Well above 6-7k wide open throttle will be on the main jets. If you bike has a K&N then there is a good chance someone has also put a dynojet kit in too. You may even have an extra hole drilled out in the slides as per the dynojet instructions which also coincides with this noise you having. The extra hole does not help with these bikes.

You wont know until you strip the carbs down to investigate. Have a good read through the following threads.
http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=14214

http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=28922

And then it's time to remove the carbs, open them up and have a tinker. It would at least be helpful to know what the setup is to begin with.

Either that or it's time to get the bike on the dyno and get the dynotech to tinker with them, but this wont be cheap and not many dynotechs like or even know how to work with carbs these days. I suggest you have a play with them first, get to know your carbs and what does what. Get things as close as you can by feel, real world road test, then once your happy do a single dyno run to see how accurate you have tuned things and go from there to fine tune.

It may sound a bit scary removing the carbs and changing things but it's really not too difficult if you competent with the spanners. Once you have done it a few times it gets easier and you will wonder what all the fuss is about with working on carbs. These carbs are very basic and easy to work with. If you get stuck with anything we are always here to help.

(:-})

When I bought mine it also came with k&n and dynojet.. I hear a lot of you guys dont like it.. I have the stock jets from po.. would the bike perform better with the stock set up. I also have erion racing pipes.. ? Thanks

Did you fix the backfire? I get a little backfire on decel..