ya I had a feeling it was from there lol! Thanks for the info! Report back if you change anything on the scoot!

 

been putting some more miles on the bike, I had some coughs when I was too quick to turn the enricher off, other then that it hasnt done anything weird when fully warmed up so thats good. I think its good, not real sure how to check, getting some discoloration on the pipes at the heads which I have always understood to be a sign of lean, plugs are still on the off white side, so not real sure where to go.

Maybe try the 190 main? Seems liek an awful lots of jet for a mild cam and stock motor though.

 

I thought #50 and #195 was pretty high for an 88 Engine with TW21 Cams which is a Mild Cam but is running like a Champ ..

 

Instead of worrying about the color of the plugs look for ceramic damage around the plug tip, also if it is running extremely hot the tips will show signs of melting. This of course if you are using the standard plug. (Champion RA8HC) or other brand.

If you are wasting money on Platinum or other type then disregard above advice. Since HD recommends replacing the plugs every 5,000 mi the extra spent on other than standard plugs is a waste of money.

My front plug has always been white and the rear plug shows a little coloration, been that way for 135,000 miles and still running strong. Blame Mr. Newton for the rear plug showing a different color than the front.

 

I think I might just have to try the same setup you are running, jets are cheap so might be worth it. You didnt mess with anything else right? needle, emulsion tube, slide, etc?

Not gonna lie, its been a while since I replaced my plugs. I'll pick up a new set of the standards. I didnt see any damage or melting, maybe I'll snap a pic of them when I have them out.


Did do a 50 mile freeway blast and back yesterday, overall the bike feels good. It did cough a little after taking off but nothing else off. Mileage hasnt been the greatest, in the mid 30's range but that was mostly canyon riding. I'm sure yesterdays run would have averaged better.

Think at this point since I dont really have a ton of experience of nailing a carb settings down (I understand how they work, can rebuild them, change settings, but knowing if I am dead on the settings is something I wouldnt be able to tell someone how to do) I think I will try a sight bigger main as sort of an experiment, throw some new plugs on and see where I end up.

The whole point of starting this thread was to make sure I wasnt going to damage the motor, think I am good there, so now will just keep tinkering away. Appreciate everyones responses, kinda cool messing with it, posting here, messing with it, posting, lol.

 

To be honest; don't believe anyone (including me) actually knows how to set-up the CV carb without the aid of some sort of test equipment. If that is a flow meter or exhaust sniffer I don't know.

And here is why. Both jets feed the engine at the same time, especially off idle. The low speed jet works between idle and about throttle open to 60mph more or less.
Then the high speed jet is suppose to be feeding the engine, but there is nothing to make the low speed jet quit working. Therefore the main jet is just adding fuel to supplement what is already feeding the engine. Both jets work off the Bernoulli principal of increased speed in a fluid = low pressure.

Also, there is no (or I can't find) a static setting for the idle screw on the front side of the carb. which adjust the butterfly which adjust the air flow through the carb. which adjust the fuel flow of the jets.

Now your poor mileage may be caused by the float setting. It may be allowing the fuel to reach a level where fuel is sucked up through the emulsion tube and into the engine. Or your high speed needle isn't seating on the high speed jet, again allowing fuel to be siphoned into the carb. It is possible to balance these two problems out with a needle adjustment so the engine operates normally but not correctly.

Of importance is the ability of the carb to transition from the idle jet to the high speed jet without stumble or hesitation. So this is actually what you are aiming for.
There is a dynamic way to set the float level, but that is another chapter in this novel.

If I were you(and I'm not) I would concentrate at this point to solving the poor fuel mileage at this time. Max power is someone else's cup tea, not me. My bike is for hassle free touring ie: easy starting, smoothing cursing, good mileage and in general easy of operation.

 

600 Miles since last posted .. As long as keeps running like this not messing with it anymore .. Quite Happy with the Throttle response all through the Range .. Averaging around 40 MPG even with a heavy throttle hand and that's good enough for me ..

 

Agreed, if I can get to that point, I feel like performance isnt far behind. I jsut feel bieng in the 35 ish MPG range is a touch on the low side for being a relatively conservative rider, and makes me think something is off.

WIll have to do more research and see where to go. I'm definitely going to keep riding, but no harm in tinkering as I go. I'll be sure to keep updating as I play.

might have to try that same setup and report back! Thanks for the follow up!

 

There is a way to "test" these circuits individually.

Take off the air filter and look into the carb, you will notice that at the 12:00 position is an elongated opening, this is the static air that the diaphragm works against. At approximately the 10:00 position is a hole, this is where the enricher gets it's air/fuel from. At the 07:00 position is another hole, this the air for the low speed jet. The hole at the bottom of the carb is not used for anything.

Now; start the bike and get it to run without the enricher(choke) on. Look into the carb and see if fuel is coming out of the emulsion tube needle area. If yes you may have found your problem.

Now place a finger over(block) the hole at the 10:00 position; if engine rpm changes your enricher(choke) is leaking. Adjust or clean. NO?

Now place your finger over the 0700 hole, engine should stumble and die, if it doesn't then you have found your problem. It is the needle is not seating in the high speed jet. Which brings us back to check number 1. BTW: you don't have to let it die, just a reaction will give you your answer.

If the hurricane(Dorian) doesn't wipe me off the face of the Earth I'll check back here.

 

Thanks for the tip! I will give that a shot for sure. Bike runs well when fully warmed up, will cough once, maybe twice during warm up cycle, but overall best it has ever ran but.........gas mileage is dismal. Like 33 dismal. I put 4 gallons in today when the trip odometer read 133 miles.....

my pipes seem to be discoloring near the heads too, which I understand some think is normal, some dont. I would have assumed that means lean (heat), but also could understand rich making the same discoloration (raw fuel in exhaust).

Hope all goes well with that hurricane buddy, that is some scary stuff! Report back in and let us know you made it out okay.