engine running rich-advice thoughts please

[philhnottm]

Apologises for this basic question.

If an engine runs rich would it mean that you may loose some performance??


The reason i ask is im running a malossi 210 , i have only ran it on pre mix at 3% rock. It also chucks out a lot of thick black oil out of the rivets of the RH JL pipe

For reasons unknown it is also very poor at top end compared to its peers.

I reduced the mix to just over 2 1/2 % and my top end increased by about 5-6 mph

The smell appears to be different and a mate suggested that this is the oil burning as opposed to not being used and just chucked out the carb and pipe rivets. (more of a burning smell as daft as it sounds)

I am how ever concerned about damage and seizing if i run it too lean .

Any thoughts suggestions welcome as ever

thanks

phil

[goldeneye]

if its rock oil sythesis fully synth oil, 2% will do, and 3% on a long run, thats what i used to run mine on. (but with castrol TTS)

[philhnottm]

if its rock oil sythesis fully synth oil, 2% will do, and 3% on a long run, thats what i used to run mine on. (but with castrol TTS)

jeff,
Yes fully synth.
so if ive been overloading on the oil for the past six months every fill up would that explain my post ??

Phil

[magg]

Apologises for this basic question.

If an engine runs rich would it mean that you may loose some performance??


The reason i ask is im running a malossi 210 , i have only ran it on pre mix at 3% rock. It also chucks out a lot of thick black oil out of the rivets of the RH JL pipe

For reasons unknown it is also very poor at top end compared to its peers.

I reduced the mix to just over 2 1/2 % and my top end increased by about 5-6 mph

You are not running rich or lean. It has nothing to do with the amount of oil. If anything, you might be too lean and you need to up your main jet if you want to continue to use those amounts of oil.

I think you're putting too much oil in. Leave it at 2%.


When you reduced the amount of oil in the mix (to 2.5%), you increased the amount of fuel. So if more fuel makes it run better, that means you've been too lean earlier. Good thing you haven't seized.

All that oil makes it hard to jet properly. It might give you the impression your running rich because oil doesn't really burn as well as petrol does, while in reality your too lean. You might be too rich on smaller throttle openings, but there's really no way to know unless you get back to the proper 2% ratio and start jetting your carb over again.

Is your scoot originally premix or does it have an oil pump?

The only reason you'd want to run 3% or close to that would be if you're running for extented periods at WOT. But then you'd need to rejet for that.

With an oil pump at max revs and wot you'd be close to the equivalent of 2.5-3% oil anyway, but you'd be down around 1.5% and even less at idle and lower revs.

[philhnottm]

Reply to magg

its not running on a auto lube.

It was about five months set up on a dyno and ran fine.

Does this suggest its not jetting ???


Its done nearly 7000 miles this season since the dyno and had new rings but just appears really slow at top end.

The pre mix thing is really confusing as soem people quote 2% others also swear by 3%.

Would there be a change of jetting once it had been set up on the dyno having done so many miles??

phil

[magg]

Reply to magg

its not running on a auto lube.

It was about five months set up on a dyno and ran fine.

Does this suggest its not jetting ???


Its done nearly 7000 miles this season since the dyno and had new rings but just appears really slow at top end.

The pre mix thing is really confusing as soem people quote 2% others also swear by 3%.

Would there be a change of jetting once it had been set up on the dyno having done so many miles??

phil

Well it could be a lot of things. Do the simple stuff first. Stop putting in all that oil.

Assuming the jetting is spot on, the reason for belching all that smoke could be your 3% mix or a leaking clutch side seal. To rule out that, try this:
http://modernvespa.com/forum/topic78579

Your 3% mix will also cause a little extra carbon build up in the combustion chamber and in your exhaust, especially if you use your scoot for just riding around town. If you let that build up for a while, you're definately going to feel the performance drop.

If you have auto lube on your engine, I think the most reliable thing would be to go back to using that. It'll minimize the carbon build up and make for cleaner running in town.

[C*NTSPEED]

ive never ran 3% in any vespa ive had and i ride throttle wide open everywhere

[LI150]

ive never ran 3% in any vespa ive had and i ride throttle wide open everywhere

Same here