Yamaha TRX850 Enthusiasts Forum

Hi all

Since fitting my FCRs at the start of the season, I've done about 2000mls of great fun and trouble free however, the bike has a tendancy to make quick "pshit" sounds with a bit of a power loss/cought type thing. This happens at low revs and cold engine but sometimes does it even after riding 10miles. Also noticed that there's some greassy/oily stuff on the engine's left side, coming out of the little K&N type filter that replaces the link pipe back to the standard air box.

The bike starts fine first time and notice no other issues throughout the rev range, power delivery is good. I fully serviced her at the season start with new oil/filter and plugs, fuel consumption is good, engine oil level is on the higher side but used to be like that before as well.

Is this normal or not and if not, what's the fix?

Cheers
A.

Sounds like it`s coughing back through the carbs a tad, not too much to worry about as it can happen when the bike is cold and when warm it might be down to a little over zealousness with the throttle.
That breather from the cam cover will also have a tendency to show some oil, especially if as you say it`s perhaps a bit overfilled.
To be honest I don`t think you`ve got much to be concerned about, you could always undo the float bowl centre caps (access to the main jets) and let the fuel out, there `might` be a drop of crud or moisture / water in there.

yes I get the same when cold.. thats funny here in sunny Queensland.
Usually if the bikes been sitting for a week or two for the first few seconds it may spit and fart a bit back thro the carbs or putting along for a while its only done it a couple of times coming to pull up at the lights its given a bit of a cough.
The oil I get weeping down the breather when on the sidestand I find is tacky and sticky and red like the air filter foam oil that I use and there is a joiner in the breather pipe right above the frame where it drips out of then onto the alternator cover .
Damm annoying and messy, next time I clean the filter I was wondering if the spray on filter oil will fix this

I've actually got the breather pipe running back into the twin sock over the bellmouths

My breather pipe exits at the rear number plate. Stainless braided with a one way valve. Periodically see crap dripping out.

How does that one way valve actuate, is it simply a rubber flap type?
You wouldn`t want to restrict the breather in any way, it`ll just sap power from the motor if it can`t breath effectively.

Thanks for the answers guys, glad to read it's normal.

Last one... Does your rex fart about more now with the FCRs rather than standard carbs, i.e. when dropping down a gear a letting the bike slow down on the engine break? (duno how you say in English, so just translating direct from French )

Cheers
A

drix wrote:Thanks for the answers guys, glad to read it's normal.

Last one... Does your rex fart about more now with the FCRs rather than standard carbs, i.e. when dropping down a gear a letting the bike slow down on the engine break? (duno how you say in English, so just translating direct from French )

Cheers
A

If you get bangs when closing throttles you are lean on the slowjet....
I was rich on the slowjet, went down one size...then it was popping as crazy....turned the fuel screws out a bit and voilá!

Mincehead wrote:How does that one way valve actuate, is it simply a rubber flap type?

No Mince ,it's got a large ball bearing in it that seals when the bike is off.