Something wrong when excelerating in first

[Jteale123]

Hi all.

Some of you may remember that my storm was completely submerged in water 6 months ago but all sorted now.

I still seem to have a problem when excelerating hard in first gear. It's like the bike is missing or not getting enough fuel. Every other gear is fine. Just first gear has this problem.

Has anyone experience this before?

[mattycoops43]

I try not to, it gets scary too fast!

[2wheelsagain]

What part of the rev range?

[Jteale123]

Certainly up to 7k revs. I try not to go above that.

I was thinking it was something to do with fuel but she runs fine up to 7k in any other gear.

[Jamoi]

Not a grabby clutch is it? Do you get juddering when feeding out the clutch lever? Or do you get bogged down when rolling open the throttle with the clutch out?

[kitsun]

It could be the fuel tank breather. Ifuel demands are higher at sustained high revs ie first gear and if the breather pipe is constricted , partial vacuum in the fuel tank would restrict fuel flow into the carbs. Leading to fuel starvation as your carb leans out due to falling fuel in the carb bowls. This is a normal problem with gravity feed fuel tanks in large capacity bikes when there is a restriction at the tank breather.

Kevin Cameron documents this in his book "Sportbike Performance Handbook" and I have to say it makes a fantastic read. Also in the book, there is an explanation regarding the carb runner intake manifold "restriction washer", apparently it's there to increase the velocity and keep air moving into the cylinder at BDC to ABDC.

[kitsun]

It could be the fuel tank breather. Ifuel demands are higher at sustained high revs ie first gear and if the breather pipe is constricted , partial vacuum in the fuel tank would restrict fuel flow into the carbs. Leading to fuel starvation as your carb leans out due to falling fuel in the carb bowls. This is a normal problem with gravity feed fuel tanks in large capacity bikes when there is a restriction at the tank breather.

Kevin Cameron documents this in his book "Sportbike Performance Handbook" and I have to say it makes a fantastic read. Also in the book, there is an explanation regarding the carb runner intake manifold "restriction washer", apparently it's there to increase the velocity and keep air moving into the cylinder at BDC to ABDC.

Here is a scan of the relevant bit from David Cameron's book:-

[img]/Users/Kitsun/Desktop/David%20Cameron%20article.jpg[/img]

[Jteale123]

Thanks for the help and scan there.

I just checked my breather and it all seems fine. I also was giving it some high revs in others gears for long periods today and it was fine. Only seems to be in first gear.

The clutch seems fine. No juddering.

Kind of lost now

[Jteale123]

Hi guys.

Please help.

It seems to be getting worse. It happend last night in 3/4th too. Felt like it was only running on one cylinder and some strange noises coming from over run. Any ideas?

I am stuck

[Wicky]

Carb manifold air leak? or an air leak somewhere in the intake system?

[VTRDark]

strange noises coming from over run

Like what , Your going to have to be a bit more descriptive of your symptoms otherwise we are just guessing. I don't understand the connection between gearing and misfire type symptoms, that makes no sense. What speed and revs, gearing is irrelevant. What have to done to the bike since it took it's dip.

(:-})

[Jteale123]

Hi all.

Well here are the symptoms. It was only happening in first and second gear under hard excelaration but now it's happening at constant revs. It's like its fuel starved/air starved missing etc.

The noise I hear on slight over run sound like air escaping every beat of the engine.

After the bike went swimming I cleaned out the carbs. Did about 4 oil and filter changes. New fuel and cleaned air filter.

I am kind of getting worried now as when I went to pull away a couple of times today there was no power. Like I was running on one cylinder. Pulled in the clutch and gave it a rev and all went back to normal but still with juddering under eceleration

Cheers for all your help in advance.

[VTRDark]

Mmmm Electrical possibly how deep did the bike get in water then and was this dirty flood water? The air sound is a strange one. You have got the front breather pipe connected on the airbox haven't you. It can be a bit fiddly to put on when putting the airbox back on if you can't get your hand under the front of the airbox by the snorkel.

I would have had both heads off if there was enough water to get inside the engine. What about the coolant is this all OK and temperature normal.

It don't sound like a well bike. How is it at idle speed and revving at idle in neutral. If it's misfiring you should hear it at idle too, it should be pretty obvious unless it's intermittent. It may also be worth pulling the plugs and checking the colour as this may give some clues. Change them for new ones at the same time. I expect moisture/water has got in all around there and under the plug caps/ht leads.

Double check you have the petcock vacuum on the right nipple, not on the bottom. This is a common mistake. I just want to rule it out in case, and it's a simple check.

(:-})

[VTRDark]

I've been having a think about this. You say the bike was completely submerged in water.

After the bike went swimming I cleaned out the carbs. Did about 4 oil and filter changes. New fuel and cleaned air filter.

This is not enough for a bike that has been completely submerged. No where near enough, before even attempting to start the bike.

I'm gonna leave the air thing for now, but I think you need to thoroughly start going over all your electrics. Start with the plugs and clean the front cylinder drain hole out, test coils, test the charging system, Check the ecu's, spray a water dispersant over all your connections. Electrics really don't like water and could cause all sorts of problems.

The next thing would be the fuel system. It would not surprise me if you still have crap in the carbs. Did you give them a thorough clean. See the following post.
http://www.vtr1000.org/phpBB3/viewtopic ... 30#p337695

If the airbox filled up with water and I expect this is mucky dirty flood water we are talking about here, then there would have been all kinds of crap getting inside the engine through the carb throat. Then there is all the water that would have backed up through the exhaust system so the exhaust packing will be shagged.

This is a worry, especially as you have been giving the bike a hard time since, under hard acceleration Your lucky the bike hasn't hydrolocked but there may be some internal damage from grit and crap that's got into the engine and gearbox. Is the oil pump even still functioning correctly. What state was the oil in when your first drained it? How much dirt and grit got in with the water.

(:-))

[tony.mon]

I'd suggest that you pull apart, clean, check, grease with non-conducting grease (dielectric grease) and reassemble, all of the electrical connectors on the bike including the main connector blocks going to the two engine management boxes in the tail.

Next time it does it (provoke it if you can) see if you can (carefully) check to see which cylinder is not firing- the exhaust pipe will be cooler.
I suspect something simple like a coil or plug cap breaking down.

So finding out which cylinder it is is a good place to start,a s you can then swap components over front to rear and vice versa to find out which it is.

But cleaning water out of all the electrics needs doing anyway, as the connector will corrode or degrade and give you more problems in future if you don't, and apart from the special grease, costs nothing except a little time.