Engine Noise 1998 VFR800fi

Hey Everybody :thumbsup:

I need some help,

During deceleration in any gear 1-4 (after that its too loud to hear) in zero to 5% throttle position meaning coasting or less I hear a sound comming from the front of the engine.

At first I thought it was a solinoid clicking sound but now it seems a little louder and I think it's a timming chain slapping type sound.

Bike has 28k miles and valves never adjusted to my knowledge, otherwise it's be well kept since I bought it with 14k.

Trouble is I ride infrequently and can never be sure except it dosent sound correct. What is it? :crazy:

 

Could it be the intake flapper. Have you disabled it - as most have done?

 

Cant be timing chain, 98 VFR has Gear driven cams... Check for loose plastic... loose bolts. Does the noise change if the clutch is held in or out?

 

DAT IS DA FLAPPER VALVE!!!!:ncb::ncb::ncb::ncb::ncb::vtr2: lol

If it sounds kind of like a plastic bag hanging out a window going 60mph then that's what it is. Totally normal. It opens at higher rpms to allow the engine to breathe easier and closes at lower rpms to offer better low end torque. Lots of guys remove the vacuum hose to it and seal the hose and leave it open. Don't know if it makes a difference on the butt dyno or a real dyno for that matter, but it gets rid of the flapping sound.

EDIT:

Pull the gas take up and you'll see a brass looking solenoid thingy and two openings at the front of the air box. one with flapper the other open.

 

You live either way to close to Wisconsin or Way Way to close to Canada!!! I live in Northern Wisconsin where people actually talk like dat!

 

Michigan work for you? lol

 

Thanks for all the help! The Ol'Flapper valve eah, I can feel a little butt dyno boost at 5k RPM when the flapper is suppose to open and presumed Honda did their R&D so I left it operational.

If I'm understanding correctly as long as the Flapper is working properly the noise is just a nuisance right? So it seems the boost is actually because the engine is starving for air at 5K rpm, thats Bad.

I need all the low end I can get as having installed a Wolf exhaust, K&N and Power commander and weighing 215, so is there any way to make it open sooner like 4k rpm? or is the apparatus better left disconnected and forgotten?

 

IMO it seems like from other VFR owners that changing your front tooth sprocket -1 will help with the low-end. That, or you can go +2 on the rear sprocket. or if you want to go the expensive route you can get a power commander for it but you have to go to a dyno to make it worthwhile.

 

Yep. Lift the tank, pull the vacuum hose off the solenoid on top of the air box (left intake) and plug the hose with a screw (or something), tuck it away somewhere and voila ! Some people also pull the snorkel off the right intake. I did for a while then put mine back on as it sounds a little funny at idle.

With stock exhaust and the snorkel off it gave it a little volume when you cracked it. But with my new pipe - it makes plenty of noise as is. Snorkel back in.

 

I tried the snorkel off and the intake sound goes way up, kinda cool like a twin but too loud for me. I do need a new chain and planning the 2 tooth increase out back.

Also to answer i700s question the noise is only in gear clutch out or engaged.

Looks like I need to get it on a dyno too as I'm using a generic mod map off the web, runs pretty good but I'm sure it could be better.