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Ace 100 fuel oil ratio

Posted: Mon Mar 25, 2019 4:15 am
by mac
I,m starting out with a fresh engine and stock jetting at about 840 elavation. Should I run it as the book says at 16:1 for maybe a tank full and then go to the 20:1 ? I won,t be out on the road and will mainly be doing light trials and trail riding. Should I start with the needle in the forth notch (top) as the book says ? I would like to eventually go to a 32 or 40:1 mix,but I need to order some different jets to compensate for more fuel,I think. As is probably obvious,jetting is not one of my strong points.
Had to edit because I think I had it backwards on the needle clip position. The book says forth notch,that would be the last notch from the top of the needle correct ?

Re: Ace 100 fuel oil ratio

Posted: Mon Mar 25, 2019 4:41 am
by taber hodaka
In today's world I would never use 16:1 I would use good oil and start at 32:1. I would get the jets you need first. Remember the ace 100 manual is only a supplement book the manual is the ace 90 manual that covers this discussion in pictures and detail. For now -----Clarence

Re: Ace 100 fuel oil ratio

Posted: Mon Mar 25, 2019 5:53 am
by socalhodaka
I’ll double what Clarence said.

Re: Ace 100 fuel oil ratio

Posted: Mon Mar 25, 2019 9:16 am
by olddogs
Remember with jetting its always best to start rich and then try leaner. Spark plugs are much cheaper than pistons. Top notch is the leanest needle position, lowest notch the richest.

Re: Ace 100 fuel oil ratio

Posted: Mon Mar 25, 2019 6:48 pm
by junker2k
Those radio's were back when we did not have real 2 cycle oil. We would go to the auto store and buy a at can of motor oil, then add it to 5 gal gas. It would smoke like he'll and two plugs. The first real 2cycle oil I remember other than bean oil was Stern C. The oil has come a long ways in last 55 years.

Re: Ace 100 fuel oil ratio

Posted: Mon Apr 06, 2020 3:31 pm
by bcruder
Back in the 1950's, there were no commercial synthetic oils (although aircraft could use ester oils). Only a few petroleum oils even had detergents. Still, there were some low-residue oils marketed for two-strokes, especially for boats.

As oils for four-strokes evolved, so did the two-stroke products (although some terrestrial consumers did still use non-detergent 30 wt for two-strokes).

The 70's were different.

Rather a lot of racers used Golden Spectro oil (which has not actually changed as much since then as some of its competitors). I still remember its unique odor and eye irritation. Klotz had at least one product that was not entirely castor including a version spiked with nitropropane. Both Jennings and Blair (two-stroke experts associated with British road-race teams) found that as little as 10% castor mixed with petroleum provided enough cylinder/ring protection with far less carbon residue. Castrol sold such a premix in Europe but I cannot say whether the same product was marketed in the U.S.

Those of us who ran Ossa as well as Hodaka used Full Bore oil (both premix and transmission) from Yankee Motor Company. The premix was before its time, a mixture of vegetable oil (didn't smell like castor), synthetic (probably to replace the bright stock which is what makes the smoke) and petroleum oil (probably only straight stock). Even then it did not smoke much when properly jetted and did not have the irritant quality of some recent synthetics.

We ran it 20:1 on Hodaka 100s and 125s and 32:1 on Ossa 250s.

I have an unopened case somewhere in the garage and intend to try the oil again when I find it but only with non-ethanol gasoline.

I am re-animating, a 72 wombat, a 75 Ossa desert phantom and a non-stock 79 Husky 250 that had been run in factory-support MX. There is also a 72 Ossa pioneer in pieces. All should still run just fine on the Full Bore.

All of the oil from those years was designed to work with leaded or unleaded gasoline but that was long before ethanol.

Re: Ace 100 fuel oil ratio

Posted: Mon Apr 06, 2020 4:58 pm
by matt glascock
Very cool bit of history here. Thanks for sharing that.

Re: Ace 100 fuel oil ratio

Posted: Mon Apr 06, 2020 8:37 pm
by taber hodaka
Well I think Bardahl 2 cycle in the 60's :was synthetic. Held the worlds record for the most consecative races without engine failure. Couldn't beat it then and I am not sure you could beat it today and I am too old to change. If you stuck a piston generally it did not hurt the piston the piston did not melt or pull the aluminum. As the lube was still there held by the magnetic film. Love the old days --------Clarence--------------

Re: Ace 100 fuel oil ratio

Posted: Tue Apr 07, 2020 1:28 am
by ossa95d
Thanks for that walk down memory lane bcruder! Nice to see another Hodaka/OSSA guy out there!

Re: Ace 100 fuel oil ratio

Posted: Tue Apr 07, 2020 2:11 am
by taber hodaka
Ivan I was also so lucky to have been the OSSA, HODAKA, TERRAJET, CHAPALLAL dealer In Kalispell Montana. For a few years was a state diestribuetor for BardahI. I still have a orange Pioneer and a street bike ossa that probably need to go along with the old Honda Asscott 500 single and many more. Clarence

Re: Ace 100 fuel oil ratio

Posted: Tue Apr 07, 2020 2:29 pm
by ossa95d
That's awesome Clarence! I'm always impressed with your well grounded comments on this forum and your sense of humor.