Derestriction Help

Sounds like a carb problem to me, you may have leaned it out a bit too far so when it warms up it leans out a bit.

 

Would've thought it was rich; cold engines like to be rich (ie, choke), so they run good rich. There it warms up it is too rich.

 

Thinking about it Fiddy rox has probably got it right, either way it's a carb issue.

 

I checked my spark plug last week and it was very black, so assuming it was running rich.
Since then I've played around with the filter and made it run leaner and also changed my mixer oil to a higher grade fully synthetic (which is reccomended for my bike according to the owners manual).

Just checked my spark plug out and it's black all over and gooey, so am assuming FiddyRox is correct in saying it runs at the preferred level of richness when cold but too rich when warmed up.
Is this due to having auto choke?
It sounds like making the bike run leaner would benefit the performance and engine? (I necessary I might have to drop a size in jet)

Cheers,
Oliver

 

I run my bike a little rich and generally it hasn't caused any issues. However it didn't like the hot weather and like yours it ran okay cold but when it heated up it became hesitant, I think it was down to the warm air being less dense causing it to richen the mixture, Since the weather has cooled down it's running good again, so if the weather warms up I'll drop a jet size.

 

Mines doing it when it's hot or cold.
Runs excellent for first 10mins but once engine warmed up regardless of the ambient air temp, the first 10mph bog down.

ATM I've got the racing clutch springs on (malossi yellow- little ones)
And I think this might be causing the bike to rev too high from a stand still until the powerband kicks in.
But what I can't understand is why it's good for the first 10mins and then crap afterwards?

It's the same from cold, slow to 10 but 0-10 is still really quick even when cold just ALOT slower when warm.

Ive tried all the jet sizes from
My stock 53 up to a 60.
60 being too rich (spitting unburnt fuel out exhaust) and 53 (so lean it caused the bike to cut out due to too much air to fuel)
And this has happened with the stock clutch springs and rollers in and with the malossi clutch springs on.
I've got a 58 on ATM which seems to give the best results with the malossi air filter, removed carb baffle and removed airbox snorkel.

Which has lead me to believe its a transmission problem. (ie revving too high)
But what do you guys think?

 

Looking back at your posting I think that there are a couple of issues.
I'm a little confused about your exhaust, you talk about baffles and removing the padding. Padding simply absorbs sound, it will not affect performance unless it comes apart and blocks the flow.
I mentioned in an earlier post that your probably better off with standard clutch springs. Stiffer springs open at higher revs and remember were not talking about higher revs of the engine necessarily but higher revs of the drive from the variator being partially open.
So if your clutch is engaging when your variator is already halfway open then acceleration will suffer until the speed builds up. Put the standard springs back on and let your variator work properly.

I still suspect that the drop in performance after 10 minutes is down to jetting but change the clutch springs first.

 

Yeah my apologies I got baffle and padding confused, have now realised what you said.
My exhaust has padding, which in earlier Posts I was considering removing to increase sound (and at the time I believed performance) but decided against this to reduce damage to engine and attention from coppers, sorry if I wasn't clear.
I tries standard springs and stiffer and there was not much difference, as mentioned I experimented with different jet sizes using stock spring and racing springs but kept the stock rollers in for the experiment to give a better idea of any improvement between jets and springs.

I'll play around with the variator and clutch, is suspect as originally said 'stock clutch springs and different rollers will work better'.

Thank you everyone for help, I'll play around with the transmission a bit more and see if that makes a difference.
This really is a tedious job, I've been tweaking ad playing for weeks an still haven't perfected it but hopefully the end result will be worth it.

Cheers,
Oliver

 

Is there anyone with a rolling road around you.

 

Mr Bizzle - I think there's one at a bike MOT centre close by, I'll look into it.
I see where your going with this and it's a pretty good idea, certainly make it easier to understand how the bike is running at the moment.