E85Forum.com

pwestre · Joined: 03 Sep 2005 Posts: 7 Location: MN

Has anyone tried converting an old Honda to e85?

I am trying a 33%/Gas blend. If it is possible to go all the way to FFV I will.

specialgreen · Posted: Sun Sep 04, 2005 9:44 am Post subject:

You mean a CB750 motorcycle? You probably already read the thread "small engine conversion" at http://e85forum.com/viewtopic.php?t=6 , and the extra info in "carb convert" at http://e85forum.com/viewtopic.php?t=63

My GS500 is alot like the CB350: it's basically just like the 750cc motor, with just two cylinders and two carbs. Mine is a '92, but the design (2 valves per cylinder; each carb with just one main jet fed by a needle jet, plus an idle jet) are the same going back to the GS750 from 1976. Honda's 1980 CB750 is probably more advanced than the current 2005 model GS500!

pwestre · Joined: 03 Sep 2005 Posts: 7 Location: MN

I took the bike for a 20 mile test ride today. It ran fine. I noticed that it seemed to run cooler. It seemed to run fine with no misfires etc. I am not going to do any further conversions for now just to see how it runs. I printed off your article and am going to give it to my motorcycle mechanic so if I decide to have it converted to e85 he has your information for tuning.

Just a little info about the bike. It has 155 jets vice 110's in it already and straight pipes. (I bought it from an estate and the previous owner was a mechanic who must have liked loud pipes and performance.)

I have been using durablend oil but I will probably switch to straight synthetic with the next oil change. I am riding about 400 miles per week commuting to school right now so it will give me a good test bed.

Most motorcycle people that I have talked to have had the same reaction that I had. The old Honda's were bulletproof so it is a good testbed. I will put my metric bike up against any new HD and it will hold its own for service and reliability.

I am using regular 87 octane to blend with the e85 right now but I will top off with premium on every third fill as a precaution.

Lgodave · Joined: 01 Sep 2005 Posts: 28 Location: WI

Hi pwestre,

Your experiment is very interesting. I wish you the best of luck and look forward to reading your results.

However, I wanted to comment about your desire to top of with Premium (93 octane?) every third fill up as a "precaution".

I don't own a motor bike, and I'm not sure if your Honda requires 93 octane to begin with, but since E85 is up to 105 octane I don't see why you need to spend the extra money for 93 octane when the Ethanol should be providing enough of a boost to the 87 octane to keep you going...

If you are a big fan of Fuel Detergent Additives (which many think Premium grades have more of) I'd suggest buying a TOP TIER brand gasoline. You don't have to buy Premium to get the higher detergent additive package, all TOP TIER fuels have the higher amount of additive.

www.toptiergas.com

specialgreen · Posted: Thu Sep 08, 2005 5:26 pm Post subject:

E85 won't leave any varnish, so there's nothing to "clean out" by running premius gas now and then. There's no computer to "trick" either. It doesn't sound like it would change much.

One thing you might consider doing is to Kreem your tank. Ethanol can eat away at soft metals, and old tanks used tin-coated-steel. Also, any ungalvanized aluminum could be an issue someday (not much of that on an old bike).

Other than Kreeming the tank, I can't think of anything much. Be sure you have a fuel filter, because ethanol will loosen any crud in the tank or lines.

pwestre · Joined: 03 Sep 2005 Posts: 7 Location: MN

I talked it over with my mech today. Only recommendation was to use alcohol resistant carburetor floats. Bike continues to run great.

On another note it sounds like I can convert my sonoma for the price of a single injector.

With the rain this week I haven't done much riding.

pwestre · Joined: 03 Sep 2005 Posts: 7 Location: MN

I already have inline fuel filters installed.