Base ignition timing on earlier carbureted models.

A common performance trick on most every 4-stroke AFAIK is to bump the base (initial, trigger) timing and run premium fuel.

I have done this in single cylinder bikes and ATV's, my '95 Chrysler Lebaron GTC (Mitsubishi 3.0 v6) and many others.

The biggest drawback ,once set properly is possible spark knock if if you don't run high test.

My bike calls for 91 RON fuel or about 88 octane R+M /2 which is pretty much just regular gas. Going to 92 octane eth free of course is a pretty good jump and should eallow for 3-4 degrees additional timing advance.

Caution this mod is not for everyone , advancing the timing can cause spark knock and destroy your motor, particularly if it runs lean and/or with the wrong fuel. Once timing is advanced just going from premium ethanol free fuel to regular 10% etc pump gas can cause problems. Don't do this mod unless you know what your doing.

That said has anyone bumped the timing on the 750's . If so what kind of gains did you see and how many degrees above stock were you able to go?

 

FactoryPro make ignition advancer rotors for a good number of bikes, and usually offer 2 or 4 degrees. I had a 4 degree advancer on my RF900 but honestly could not tell any seat of the pants difference.

 

Timing is built into the CDI box circuitry and on a Honda shouldn't be f**ed with. :cower:

If you're looking for a faster getaway from a stop go 2 or 3 teeth up on the rear sprocket.

 

The way the FactoryPro ignition advancers work is by replacing the stock pulse generator rotor that triggers the ignition timing. Simply changing rotating the position of the lugs on the rotor (e.g. by 4 degrees) with respect to the crank position changes the ignition timing, so no messing with the CDI box (which will have it's own variable ignition timing).

 

I haven't dug into my bikes ignition so far but often the trigger or it's mounting holes can be slotted enough to get that 2-4 degrees. This won't help to do anything but wear your motor unless your are running higher octane fuel and the carbs are tuned to take advantage of it.

There is a semi-programmable cdi option as well.

I am not looking for quicker off the line at all in fact I can't stand running 6800rpm at highway speeds and will be going to 17t on the front as soon as the replacement for the 17t that didn't fit arrives. Remember 17t is stock for the 750 bike , the 700 tariff bikes got 16t to help them feel like they didn't loose anything so they are already geared pretty low.
My intention is to gain a little here and there with freer intake (K&N) , tuning (carbs and timing), freer exhaust (slightly modding factory pipes) to cover the taller gearing so it pulls just as hard as stock with lower gearing except to a few mph faster in each gear.

In my experience people try to go crazy and make big power with one mod or another. Tuners know the secret and that is to make many small changes that compliment each other, one at a time , and evaluate the benefits of each.

As an item of interest the base timing on a 700 is 15° , where a 750 is 10° but both end up at the same 35° maximum advance. That tells me that the 750 cdi boxes advance an additional 5° versus the 700 box. Also the 10 degrees versus 15° base timing has to be either in the trigger itself or adjustable. Seems like the ticket for high test fuel use is 700 trigger or trigger settings and a 750 cdi
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Too bad I don't knowing any parts bikes in the area it might be fun to mix and match some parts. Even a 5% gain in power (4 hp) puts the 700 within 1 hp of the 86hp 750 of the same design.

 

Timing advance can be kinda risky cuz some fuels are mislabeled or adulterated, and nobody checks. What you think is 91 could be 87.:mad-new:

 

So true , really tho last thing I need is more power, not like I got the suspension or skill to push the current limits ,especially since a couple HP if that isn't gonna make a difference between 0 and 80mph anyhow.

I initially got the old vf because I wanted something inexpensive that I wouldn't be to upset if I balled it up.....now that I have caught up on the history of the bike, learned of its vintage, and found out how hard good oem plastic is to come by I would rather crash a newer 600, and let insurance buy another. Otherwise I crash the vf full coverage or not and I will be lucky to get a $2K check no chance of getting it fixed or just buying another. I guess sometimes I feel like I am responsible for a piece of history.