V-Twin Forum banner

21 - 40 of 40 Posts

·
Registered
Joined
·
5,166 Posts
The stock needle and main jet can be determined by parts microfiche. Needle 27406-00, main jet 27243-95, and the 46 pilot is an aftermarket part, cycle craft through drag specialties DS-289319. 45 pilot was stock, guys drill them so beware. The stock main was a 190, 180 is fine. 170-175 mains, not for a twin cam 88, sportster needle too rich wastes fuel (was used on first year CV without accelerator pump!), tiny pilots under 45 not going to work. It would not hurt to add one or two number 6 brass washers under the needle if it sneezes a little out the intake on light acceleration. Remember the mixture screw should kill the motor when closing it (gently). No canned amount of turns on the mixture screw per internet gurus, when hot screw it down to lean drop off and then out to the smoothest idle of 950. One thing not mentioned timing. Is the ignition stock? If so no worries but ignitions that can adjust the timing can be a good and not such a good thing if damaged or not installed properly or set wrong. So can a failed VOES or in your case a MAP sensor.
After years of buying every gizmo available to man for a CV carb I won't use any of them and if I want or need more performance I use a different carburetor. This is not the case here. Stock and properly set is the name of the game with a few minor mods. At 14mpg you should be seeing black smoke and it should be stinky. Plus build major amounts of carbon. The white insulator on the plugs should be white, the main body grey. No signs of silver specs which is from detonation.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #22
Thanks for the reply Don.
So, I have ordered the 27406-00 needle and a 180 main came out of the carb, so I guess I could put that one back in, or buy another new one. I know the needle in it now is the wrong one because it is adjustable via an e-clip versus the original which as you said can be adjusted up using brass washers. I've also ordered a new vacuum diaphram spring just to make sure I have the stock spring. When I pulled the top off, the spring seat was installed upside down and probably has compressed the spring some.
As for the ignition, as far as I know it's stock, but here again, I thought everything was stock until I started troubleshooting this mpg problem, now, not so sure.
For the black smoke, while I can't see behind me while riding, where the pipes end, just under the rear of the trike, it is black and sooty, and sometimes when idling I can smell the raw gas smell. The plugs insulators are not white, kinda dark grey to blackish, the main body kinda light to dark tan. I have gotten a new set of plugs to install when I get the carb rebuilt.
I'm going to look at drag specialties and get the 46 pilot and probably a new 180 main just to be sure. I guess I can send the other jets back to D.K. or, since they were only a few bucks, just keep them for some of my sportster riding friends.
By the way, what do you think the mpg should be, approximately, after this rebuild and tune?
Thanks for all your help Don, You've been a great help. The wife and I just wanted a ride that we could enjoy, and while it seems to perform rather well, it's just way to thirsty!!!

Thanks again,
Roger
 

·
Registered
Joined
·
547 Posts
.... I'm getting 14.043 mpg...
Are you that's not 14.044? I don't see how you can get an accurate average from just a half tank of riding. That could have been 4 hours of cruising around the Walmart parking lot showing off your new putt. And what are you getting without the passenger? Around town, open road?
The P.O. is no help, he won't even get back in touch with me. .
He probably thinks you want your money back. Or maybe he just bought the bike cheap to make a quick resell, and knows nothing about any mods.

The bike runs good, idles good after warm up, but the mpg is terrible. .... I don't know what mods have been done, although it does appear to have a stage 1 kit, but not sure.
All this switching and swapping parts might just kill your drivability. You might be blaming the carb when the problem is somewhere else. Or maybe your enrichener is stuck on or somehow malfunctioning.

Here's some places to maybe educate yourself about the CV carb, at your own pace. I'm no expert, as I've never had a bike with a stock carb. Lots of nice pictures of what look to be brand new carbs.



Looking at this last one, it looks like every part you need is available at the nearest dealer, up to and including a whole new carb.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #24
rootintootin, thanks for the reply, however, 21.5 miles each way, mainly open road cruising from 55 - 70 mph. I'll let you do the math - 55727 miles, 1.511 gallons on first fill up, 55770 miles, 1.551 gallons on second fill up. My calculator tells me that I drove 43 miles from fill up to fill up, using 3.062 gallons. 43 miles divided by 3.062 gallons equates to exactly 14.043109079 miles per gallon. I did not check the mpg on the ride home the day I bought it, but, that was about 90 miles, interstate and open roads cruising 65 - 70 on the interstate and 55 - 60 on the open roads. I had to fill up somewhere around 70 miles because it was less than 1/4 tank. by the time I got home, I was back around 3/4 tank. That ain't good gas mileage, I don't care how you figure it...
Maybe I am barking up the wrong tree, but knowing that the carb has been opened up and some things changed as I posted earlier, I figured I'd start there first. Don has given me some good advice as well as another Harley rider / motorcycle mechanic that I know personally.
I don't mean to sound arrogant and don't take this the wrong way, but I've been riding since my early teens, back in the mid '60s.
As far as the P.O., when I bought the bike it came with an "as is" bill of sale, so no money back, which I don't want any way. Our contact was about some items he had taken off to replace that he said if he had them I could have them, but he never got back to me anyway.
But anyway thanks for your reply...
Roger
 

·
Registered
Joined
·
5,166 Posts
The carb issues you found are significant. The clipped needle and problem with the spring seat. Don't forget to check intake seals with all this exploration and set the float level plus clean the carb and passages
 

·
Registered
Joined
·
30 Posts
Discussion Starter #26
Don, thanks for the reply. When you say intake seals, are you speaking of the carb to intake seal and the intake to head gaskets? If you are, then I can say I have checked the carb to intake seal, it is soft and pliable. Not sure about the manifold to head gaskets, but I will be checking them as well. One question, if the intake seals and gaskets were leaking, or sucking air, wouldn't that cause a lean condition? Possibly causing a possible spit back or poor acceleration?
I have checked all passages, sprayed carb cleaner and compressed air. All those seem to be open and fine. As for the float level, I think you mentioned the measurement in an earlier post, I'll have to read back and see. If not can you give it to me?
Thanks again for all your help. As for the cycle craft jets, I'll call the local Harley shop tomorrow and see if they have them in stock, since drag specialites is a dealer only supplier, and they are a dealer for them.

Thanks,
Roger
 

·
Registered
Joined
·
30 Posts
Discussion Starter #27
The carb issues you found are significant. The clipped needle and problem with the spring seat. Don't forget to check intake seals with all this exploration and set the float level plus clean the carb and passages
Don, I just checked your previous posts, you mention the float level, but no measurement. I have an actual HD repair manual coming. Hopefully be here sometime next week.

Thanks again,
Roger
 

·
Registered
Joined
·
547 Posts
It appears to me you are calculating mileage all wrong. Why are you putting in the 1 1/2 gallon that you put in before you started the test? It could have been 2 gallons or 5 gallons. Matters not a bit. Fill it up just so you know it's something you can repeat. Do your run. Then fill it to the same mark and note mileage and gallons. That way, your 43 miles comes out of the 1.551 gallons you added at the end. That math gives you a mileage of 27.724 mpg. Quite a big difference than 14 mpg and not too far off from the 30 mpg your buddy says it should be getting.
 

·
Premium Member
Joined
·
578 Posts
Rootintootin, that was an inexpensive fix. Now Roger can put the carb back together and start riding. Math is one of the best tools we have in our arsenals.
 

·
Registered
Joined
·
547 Posts
What inexpensive? He hasn't seen my bill for doubling his gas mileage yet.:)(y)
 

·
Premium Member
Joined
·
578 Posts
For a good measure of gas mileage, I would do more than 43 miles. Run several hundred miles and track all the fuel that you put in. That will give you a better idea of what it is doing.
 

·
Registered
Joined
·
11,498 Posts
You should get right at 30 mpg. It is not so much extra weight to consider, but the aerodynamics of a trike creating drag.

Sent from my moto g(7) supra using Tapatalk
 

·
Registered
Joined
·
547 Posts
...Run several hundred miles and track all the fuel that you put in....
That, or even up to a couple thousand. Just to cover all the kind of miles you put on the bike. But that's a long time to remember to write it all down. Forget even once and it pretty much blows all that work.
Nowadays, I just do it every fill up. Zero the trip meter. Next fill up, its simple math. No need to go out to 3 places after the decimal; tenths is good enough. I'm mostly looking for anything out of my normal 40-42 mpg range.
Best thing I ever did for mileage was a new carb. I was getting only 36-38 with the 8 year old 42mm Mik that came on the bike when I bought it. After fiddling with jets and rebuilding the carb, with no improvement, I put on a new 45mm. Mileage went to 43 mpg. Over 10 years later, I still get in the low 40s every time. Can't beat that with a stick.
 

·
Registered
Joined
·
8,892 Posts
all stock without the trike kit, they het around 42-45mph...
don dorfman has given excellent advice,, i wont add or detract from it.
my question about gearing,,, final drive gearing is intended to determine if the final ratio is near where it should be...a tire with over 26" diameter as will the wrong for the application pullys combination,,, ir should have a 34-70 combo for a srock 2 wheeled bike netting the overall ratio in the 3:20-3:36 range... 3:36, will make it easier to get going,, priovided the primary ratio is 25/36 tooth count,, the 34/70 final will put you in the sweet spot... your habits can kill mileage as well,,, i.e. getting into the higher gears, at lower speeds, and lugging the engine to accelerate,, causing excessive throttle input,,, leading to terrible mileage..
all that don and others have advised you on, as well as what seems insignificant gearing issue possibility..
it all has to work together,,,

just a fyi,, the larger performance engines i built,,, were getting high 20's to low 30's mpg at speeds up to 60 or so,,,
 

·
Registered
Joined
·
30 Posts
Discussion Starter #36
Thanks for all the replies,
I owe rootintootin an apology. I'm sorry.. You are correct in that I figured the mileage wrong. It's been so long, my car and truck has the average mpg in the dash so I can just look at it and not have to figure it out. After doing it the right way, it seems I am getting around 27. But given the fact that it has the wrong main jet needle and maybe a drilled pilot, I want to go back to close to stock and use Don's jet sizes as a starting point, and go from there. However, I feel that the 43 miles I rode it gives me a good enough idea. Once I get it all back together and dialed in, I will be doing longer rides to get a better average.
tall terry, as far as the gearing, I haven't actually counted the sprocket teeth, I'm hoping they are stock. The trike kit calls for the stock sprockets to be used, but they could have been changed.
Don, thanks for the float setting link, I'll checking that too. Be glad when my shop manual gets here!!

Take care all, and thanks again for all the info and help,
Roger
 

·
Registered
Joined
·
547 Posts
No apology needed. Even 27 mpg sucks.
My main concern would still be that you will lose the good drivability that you have. Somebody did all those changes for a reason. After all, you have a 17 year old bike, closing in on 60K miles. You know next to nothing about what had been done to it in the past. All this effort to return to a stock carb setting could be undoing some mods that were well reasoned and necessary. Chances are you will get a good year or 2 of basically trouble free riding before time catches up with you.
Once you get your manual, you'll need to start nosing around, looking for anything that doesn't match the pictures. If you find one thing, it could lead you to look somewhere else. Something as simple as popping off the pushrod clips will tell you if the pushrods are one piece or adjustable. If adjustable, could mean cams. Could mean tensioner shoes have been replaced. Or maybe not. You won't know until you have a look.
Good luck
 

·
Registered
Joined
·
30 Posts
Discussion Starter #38
No apology needed. Even 27 mpg sucks.
My main concern would still be that you will lose the good drivability that you have. Somebody did all those changes for a reason. After all, you have a 17 year old bike, closing in on 60K miles. You know next to nothing about what had been done to it in the past. All this effort to return to a stock carb setting could be undoing some mods that were well reasoned and necessary. Chances are you will get a good year or 2 of basically trouble free riding before time catches up with you.
Once you get your manual, you'll need to start nosing around, looking for anything that doesn't match the pictures. If you find one thing, it could lead you to look somewhere else. Something as simple as popping off the pushrod clips will tell you if the pushrods are one piece or adjustable. If adjustable, could mean cams. Could mean tensioner shoes have been replaced. Or maybe not. You won't know until you have a look.
Good luck
Thanks,
You are right, I really don't know what if any mods have been done, other than a Stage 1 kit, maybe.Yes, someone did make the changes, but did they know what they were doing??
All the research on trike kits and reading other trike riders posts, I've read that normally very little needs to be done other than a possible retune on the carb. Some have rejetted, some haven't. I'm hoping that putting in the right main needle and some known good, as in new, jets will help. I could live with 30 - 32 mpg, but like you said 27 mpg sucks!!
The manual shipped today, so maybe it'll be here this week...
Thanks,
Roger
 

·
Registered
Joined
·
30 Posts
Discussion Starter #39
Don,
I checked the float level yesterday according to the link. It looks good. The new jets and manual are due in tomorrow, not sure about the slide needle and spring, but they have shipped. I'm calling the dealer this am to see if I can get a tracking number since they said it would ship USPS priority mail.
I'll let you know how it all turns out.
Thanks..
Roger
 

·
Registered
Joined
·
30 Posts
Discussion Starter #40
Hello everyone, been a couple of days but the new spring and needle came in today and got the carb back on.
With the pilot screw set where it was when I broke everything down, 1 3/4 turns, there abouts, I took it up the road for a warm up. At steady speed, 35mph it sneezed a couple of times. Got it back home, and began the fine tune. Turned the pilot screw in until it stumbled, actually all the way in but it never stalled (hmmm). Anyway, started backing it out slowly until the rpm's stopped increasing, turned it back a bit. Put the af cover on, took it on about a 4 mile ride, still moderate speeds, no more than 50 mph, no sneeze, good throttle response, all in all so far I'm pleased. Plan on taking on a longer ride tomorrow and check the mpg again, just to get an idea.
One thing does bother me though. When I pulled the pilot screw out to clean all the passages with carb cleaner spray, I noticed some black soot on the tip of the needle, about 3/16". It wiped off, then I cleaned it with a rag with cleaner on it, cleaned right off, didn't feel any burrs on the needle.
I've pulled a lot of pilot screws out of carbs over the years during a rebuild but I don't recall any being black on the end of the needle, maybe my memory ain't as good as it used to be, but I was wondering... Since the carb had been gone into and the slide needle changed, could they have changed the pilot screw too?? Could the spring be to long on that pilot screw to keep it from seating? Like I said, turning it all the way in, did not stall the engine. I tried to get a pic before I cleaned it but it didn't come out clear enough to see it. I do have a pic of the slide needle I pulled out so you can see what was in it.
Hopefully you can see it.

Thanks,
Roger
 

Attachments

21 - 40 of 40 Posts
Top