Start up premix ratio?

[Coyote]

I will be starting my bike as soon as I get the electrical glitch fixed. I was going to go with 30-1 Is that OK or do I need 20-1? It has a 100% fresh top end.

[tz375]

I usually start at 100:0 straight gas. there's enough assembly oil to run it for long enough to check the oil pump.

If you feel compelled to add some oil, go 32:1

[GT750Battleship]

Why have you abandoned the pump Surely the pump is the way to go
Interesting to read your thoughts
Cheers,
Roger

[tz375]

I imagine that Coyote is playing safe on startup and trying to avoid premature meltdown.

[rngdng]

I just start it on straight gas also.


Lane

[Coyote]

Battleship, I have not abandoned the oil pulp. It was just a precautionary while making sure the pump is working correctly. I need to take all the precautions I can as the pumo is a ???
When I bought the bike, the left cylinder was fried. I don't want my new top end to end up looking like the last. This bike was supposed to be a quick easy fix. That plan ended when I did the initial compression test.

[GT750Battleship]

Oh,OK..every Suzuki I've started after rebore or just put back together..I just prime the lines & hold pump wide open with the pump rod with motor at idle until the shed is full of smoke,whilst checking lines for air bubbles,never had a problem,on first start up there should be enough oil already internally to lubricate things,good luck with it,that piston sure looks "second hand"
Cheers,
Roger

[tz375]

That's one detonated and seized piece of junk metal.

[Coyote]

The rings are still good though

[Vintageman]

You should always run 100:1 or more in the tank even with the pump

[Alan H]

Why? Modern fuel is poor enough.

[Vintageman]

cheap insurnace

[Alan H]

I understand where you are coming from, but even that little amount will drop your octane rating and can cause pinking (pre-detonation) if you like to spank it on the highway.
I suppose if you run it like you owned it (unlike running it like you stole it!) and showed some mechanical respect, it wouldn't make much difference.

[Vintageman]

Never had it affect pinging. And, I usually run 87 Octane Really can't get 93 unless separate hose at pump (not around like that anymore) or gas up after someone else you know who did just use higher octane… love those Harley guys. Maybe I'm jetted well and have good compression margin.

I have always been advised if you run the girls hard it's wise to put oil in the tank. It's shocking how much they say to use if you road race them for example and still run the pump.

I carry a little with me and if feel real frisky I'll drop as much as couple Oz per gal. You just have remember to warm up the plug next time you start up cold (or carry spares). That would hard to do if you have to start out cold and right into slow city traffic... I don't live in a city

With that said I won't run any oil in tank fresh rebuild. Lube things up in advance, prime pump (drill or push bike in gear) and let in run for several minutes at mid to low rpm. Don't really have to worry about warming the plug or over rev the engine if it feels like it's about to foul out. I know some say run it hard right off... I haven't had luck with that method. I'll wait a little longer for things to seat in.

Good question
The above is my current philosophy. It is something I have evolved into and may change my mind yet.
I do think the initial first minutes of running are critical and so aren’t the next few hours. After, it’s how hard you run it versus how fast it wears out

[Monkey man]

Dont make the same mistake as I did - I fired it up neat after rebuilding the carbs thinking the pump would do its job - the bike siezed big time needing a new crank rebuild - cost me £780
Stay safe and add a little 2 stroke - better to be smokey than sorry