Help - Running right rough/vibey , especially up to 5000 rpm

[HJFazer]

Hi,

As the title suggests, my fzs600 is running really rough and vibey up to 5000 revs, then it gets a bit better.

Symptoms:
If I try to accelerate hard up to 5000 in gear it Judders badly. I've had to nurse it home. Ran fine this morning. Even gently increasing the throttle makes it vibrate like Im about to stall

Things I can think that might have affected it:

1)It rained pretty heavy today and I had something similar ages ago after rain (but no way as bad on the Judders)

2) had the cam chain checked recently and while the chain was OK be did move the tensioner on one click.
3) related to the tensioner, since then the throttle has had more free play than normal.
I can't think of any other changes,

Any advice or help would be great.

Cheers

[HJFazer]

Sorry. Couple of other things,

My fuel pump had previously had an issue due to poor connection left over from when the data tool was taken out.

[darrsi]

Could be loads of things, dodgy plugs or caps, water in fuel tank, breaking down or misaligned TPS, carbs out of sync, stuffed up air filter, blocked fuel filter, etc.

[HJFazer]

Yeah, having googled it there seem to be numerous potential causes. I'm going to speak to the guy who checked my cam chain add he was the one who pointed out the fuel pump issue. Other than that I'll be taking it to a garage again on Friday I guess

[Frosties]

Did you ride to work in the rain and then leave it out in the rain? Might be worth raising the tank, WD40 inside the plug caps etc.

[HJFazer]

I did Frosties. I've just put some wd40 inside the caps, forgive my stupidity but what would raising the tank do?

[Frosties]

I did Frosties. I've just put some wd40 inside the caps, forgive my stupidity but what would raising the tank do?

I just find it gives me better access 'cos I'm cack handed 


So the camchain tensioner and throttle play is not the issue. I take it there's no improvement after spraying the plug caps?


I've got a Tiger which throws the same hissy fit in heavy rain but tends to be the coil packs getting damp - have you also sprayed the crimp connectors under the coil packs?

[HJFazer]

I've not tried riding it since as I've had to go out but will try it first thing tomorrow and keep my fingers crossed.

Where would I find the coil packs

[Frosties]

The coil packs are at the other end of the spark plug cap - piccy below. They have crimp connectors at the bottom.

[HJFazer]

Cheers again Frosties, really helpful. So wd40 in the caps seems to have worked as she's running much smoother this morning. I'm assuming replacement caps are the solution? Or, if I clean any crap from around the plugs I'd that likely to make the seal more water tight?

[Frosties]

Cheers again Frosties, really helpful. So wd40 in the caps seems to have worked as she's running much smoother this morning. I'm assuming replacement caps are the solution? Or, if I clean any crap from around the plugs I'd that likely to make the seal more water tight?

That'll help for sure. You could also try trimming the plug leads back 5mm first before buying new ones (they screw into the cap).
If the bike started ok but then progressively began to run rough it could be the plug water rubber flap that's either not fitted or set wrong. It's the flap that sits just in front of the plugs and the bottom edge should fall in front of the top of the engine - not fall just in front of the plugs. If it falls in front of the plugs then the plug wells will just fill with water.


Good luck fella 

[darrsi]

If you're considering new caps, once you've picked yourself up off the floor at the £200+ set for OEM ones, you can buy NGK SB05F ones on eBay instead which are a good replacement part for a fraction of the cost.

[HJFazer]

Cheers Darrsi, will check them out if it continues to happen. I'm hoping it may have been caused by the engine cover flap thing being in the wrong position. Will have a proper look at the weekend though

[darrsi]

Cheers Darrsi, will check them out if it continues to happen. I'm hoping it may have been caused by the engine cover flap thing being in the wrong position. Will have a proper look at the weekend though

They come in red or black by the way, myself and plenty of others on here use them and they're a great replacement.
Yamaha ones are £213.20 for four new ones. 


http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=NGK+SB05F&_sacat=0

[HJFazer]

Wow!! That's some price difference are Yamaha's made out of gold??

Cheers for the link

[Frosties]

Wow!! That's some price difference are Yamaha's made out of gold??

Cheers for the link

Gold...nahhhh - made of Mugnasium 

[darrsi]

To be honest, the way Yamaha price up their parts, there is little chance of an insurance company not writing the bike off these days if you were to have a very minor accident.
Even a rear wheel for instance is priced as new at £688.49on the AJ Sutton site, yet you can pick one up on Ebay for £25+, and it'll even be round too.
Does kind of change your ways of thinking about insurance policies, 'cos no matter what you personally value your bike at, you're gonna get mugged off if push comes to shove.