Fueling issue/carbs???

[Supermofo]

Coming home the other day on the A1 at 85 (around 5000rpm in 6th) in the outside lane. Car in front moves over and I go to accelerate, open throttle and....nadda in fact if feels like its going to die. Felt akin to being out of fuel. So pulled into slow lane and look to pull over, only at constant throttle it feels fine so I carry on. I then try and accelerate and its all good. Bout 5 miles down the road I think odd but will crack on and try and get back sooner to check things over. Roll on throttle and same thing happens. So I pull over and just listen to engine, rev it, make sure nothing's obviously fallen off/come loose and all looks/sounds good. So I pull back out and make my way home down the A414 to Hertford. Bike seems fine again so try rolling on throttle and its fine now. I try roll on and giving it the beans to the red line in a few gears all good until I got home.

This morning. All good until about 15 mins into ride on the A414 so fast A road. Again around 5000rpm in 6th same problem. As I opened the throttle/tried to hold it constant I lost power. Changed down to 5th and all good Sat at the same revs in 5th for a bit gently rolling on/off all good. So hooked 6th and did the same roll on/off all good Is it possible that its something that only happens in 6th at set revs and if so what, or is that more likely to be coincidence?

Rest of ride in I didn't have the problem, the fueling seemed a tiny bit off at lower speeds in moving traffic but I have a feeling thats me being paranoid/doing something different cos I'm aware there's something up. Giving it the beans seems all fine no problems there.

So what's up? Carbs, sh1t fuel ( I put new fuel in but that was in the morning on way in and issue was on way home), mate mentioned it could be sticking fuel pump would that do above, also thinking it could be TPS.

Bike has dynojet kit and Motad Venom cans with standard air filters and has been set up on a dyno. The problem I had above happened around 5000rpm which was the problem area before I got the bike set up (large flat spot) but since it was set up 3 years ago its been all good.

Ta in advance.

[VTRDark]

These bike don't have a fuel pump they are vacuum fed from the petcock on the bottom of the fuel tank. Is this something that has always happened or something that has only just started? Any backfiring or misfires? And forget about what gears your in for the moment, but basically your saying the bike wont go past 5000 revs. Which could be a symptom of the timing being out 180 degrees. Have you recently had the ccts changed?
If you need to take the carbs off and give it all a clean through it's a very simple job if you are reasonably good with a spanner.

(:-})

[Supermofo]

Problem only started last time I rode it, prior to that its never happened before.

Bike doesn't misfire, it does pop on the overrun occasionally but has done that for years without issue.

Its not that it won't rev past 5k absolutely as such, it sort of bogs down like a 2smoke that needs a good clear out. Happened each time for a few seconds before I've changed down as I'm losing drive. Then problem seems to go away and bike rev's cleanly as normal. My commute is 30 miles each way. Happened twice last time I rode it about 20miles into journey, and once this morning about 7 miles into journey.

CCT's haven't been changed but no noises from them.

[Supermofo]

If you need to take the carbs off and give it all a clean through it's a very simple job if you are reasonably good with a spanner.

(:-})

Think that might be an idea, thinking about it bike has been left for reasonable period of time this summer without being run due to sh1t weather (total FWB nowadays) and a 4 month old son which is our first baby so possibily carbs gummed up?

[AMCQ46]

also check how the overflow pipes are routed as there has been a few examples of that leading to bogging down. there was a link somewhere to a picture of teh best way to change the routing to make sure it works even better than Honda planned. I think it was via the superhawk forum, but someone will come along and remind me where it was

[Supermofo]

also check how the overflow pipes are routed as there has been a few examples of that leading to bogging down. there was a link somewhere to a picture of teh best way to change the routing to make sure it works even better than Honda planned. I think it was via the superhawk forum, but someone will come along and remind me where it was

Ta.

If fresh fuel doesn't sort the issue (it only started thinking about it after filling a tesco the other morning and long shot but could be that ) I reckon it'll might as well be tank off, check pipes and clean carbs.

[VTRDark]

To remove the carbs:

1: Remove the fuel tank (note the small vacuum pipes that goes behind the left hand side fuel line.)
2: Remove air filter and airbox (note positions of the breather pipes especially the front which can be fiddly to get back on)
3:Undo throttle cables
4:Disconnect the TPS (electrical plug on side of rear carb)
5:Undo the choke cable at the bracket on the frame. It should slide out the bracket. (note the routing of the cable under the water hose on thermostat housing)
6: Loosen of the top bracket on the carb rubbers at the base of the carbs. Rear one is simple you will see it on the left hand side of the carb and can get a Phillips screwdriver down through the top of the frame. The front is a little more tricky. On the right hand side just behind the radiator you will see a hole in the plastic cowl. This is there to put the screwdriver through and reach in to the clip on the front carb. It helps if you have a screwdriver the right lenth and then you wont have to loosen the rad to gain access.
7: You should now be able to pull the carbs up by push pulling in a sideways motion.
8: Now you can slide the choke cable through under that pipe and out the way. (Again note the routing of the cables. The rear one goes over the top of the rear carb diaphragm cap and routes around the back of the carb)
9: All you have now are the tho water inlet pipes that go into the carbs. one on the front left and one on the rear right. Loosen the clips with pliers and remove the hoses (There is no need to drain the cooling system, you will only get a tablespoon of water fall out)

Carbs should now lift out as one piece with the choke cables still attached. For carb strip down pics http://www.vtr1000.org/phpBB3/viewtopic.php?f=9&t=25177

(:-})

[Supermofo]

Thanks cybercarl

I've a Haynes manual I'll have to hand as well, but no doubt that will seem to be written in greek to me

[tony.mon]

1. Να απέχουν μεταξύ τους.

2. Να το διορθώσω.

3. Ιππεύσει.

[scott02464]

1. Να απέχουν μεταξύ τους.

2. Να το διορθώσω.

3. Ιππεύσει.

I was just about to say that anorl :-)

[VTRDark]

Well number 3 means ride what are the other 2.

(:-})

[Supermofo]

Update-

Ok finally had a chance Sat to take a look at things. Tank off, all the pipes look ok, Airbox off that's fine just a bit dirty (chucked a new filter on whilst in there), top of carbs look ok bit of carbon build up so gave them a clean up. Was about to take carbs off and apart when my mate say 'Whilst I start on this just take a look at the fuel tap diaphragm, be careful though as you don't wanna damage it'. So I take the housing apart and find a small split in the rubber...so hopefully problem found.

New diaphragm has just arrived at Honda Chiswick. Looks like it costs £2.50, Honda price £31 Still fingers X I'll be back on the road and blasting when I get back from Hols

Thanks for your help guys.

Unfortunately when working on the bike I noticed my end cans are on the wonk, following the exhaust path looks like the hanger on the link pipe (Motad Venom) has cracked not sure how as not been knocked or any thing. Or well still all tight and not gonna fall off just looks crap so maybe a winter job.

[VTRDark]

New diaphragm has just arrived at Honda Chiswick. Looks like it costs £2.50, Honda price £31

That's a big price difference.

Hopefully this should sort it out for you. Well done.

(:-})

[Kev L]

If you need a hand or balancing guage etc give me a shout mate, I live up on the Foxholes estate top of Gallows Hill.