Board index Flathead Power-Technical Questions, Answers, and Suggestions Evo's Thru 99 What else can go wrong

What else can go wrong

Post Sun Feb 22, 2009 6:29 am

Posts: 250

After getting the brake light problem solved on the 1991 FLT, I took bike off lift after maintenance and setting up all winter. Tried to start and gas runs out of carb overflow line onto ground. Engine turned over fine, but did not start. I did not put gas stabilizer in it this winter and guess the carb float is stuck open. While trying to start, the bike was on kick stand and the cylinder areas on kickstand side where top of cylinder meets head weeped gas on both cylinders so I know I got raw gas in cylinders. I am removing the CV carb to clean it out, however do I most likely have gas in oil and/or crankcase? Is there a crankcase drain on this 1991 motor, have not found it in the manual. Thanks for all the help, Buster.

Post Sun Feb 22, 2009 10:42 pm

Posts: 903
Location: Hill City, Ks. USA

I don't think there is a crankcase drain on the '91. You'll just have to change oil a couple times to clean it out. Drain the oil and put 1-2 quarts in. Run it for a short time and change it again. Fill 'er up with oil and run it around a while. Pop the lid on the oil tank and see if it still smells gassy.
Don't forget to pull the spark plugs and spin it over a few times to blow the gas out. Won't hurt to squirt a small amount of Marvel Mystery oil in the cyls to restore ring lubrication before you button it up and fire it over.

Post Tue Feb 24, 2009 4:16 pm

Posts: 176
Location: Carmarthen, Wales, UK
Just a thought, Buster; had you left the gas tap on for any length of time? A little gas goes a long way, and if you'd only had the tap open whilst starting the bike, and then turned it off afterwards (bitter experience with an SU-equipped Ironhead makes this standard practice on my H-D's) then it might well be that there's less gas in there than you might think.

Had similar on my 92 FLHS but the overflow diverted most of the gas onto the floor. How much has actually been lost?
72 Ironhead, goes better than it stops!



2005 XL1200R.... well ya gotta have a rat-bike!

Post Wed Feb 25, 2009 6:08 am

Posts: 250

I turned gas on to crank and it started going all over the ground out of overflow, then tuned it immediately back off. For some stupid reason, I tried it again and the same thing happened. The gas was not on more than 15-20 seconds each time. The thing that bothers me is the weeping of gas between the cylinders and heads at the head gasket. Maybe this is common, but it shows I had gas in cylinders. I have removed tank to pull carb, but due to day job, haven't got into carb yet. Hopefully some time this weekend I will be able to work on carb. I am going to do what Curt says and change oil a couple of times. I will let you know what happens. Thanks, Buster

Post Wed Feb 25, 2009 6:42 pm

Posts: 1538
No oem Evo cases have a drain in them.

Just do as Curt suggested, couple oil changes,(better safe than sorry) & clean carb..

In future when in doubt after storage, put something under kick stand to up-right bike, if you overflow then it's much less likely to go in cylinders..

FlatHeads had it right, carb on left side..

Post Thu Feb 26, 2009 6:19 pm

Posts: 176
Location: Carmarthen, Wales, UK
sleeper wrote:
FlatHeads had it right, carb on left side..

So true. Apart from anything else it deters prying fingers from fiddling with your carb settings.
72 Ironhead, goes better than it stops!



2005 XL1200R.... well ya gotta have a rat-bike!

Post Thu Feb 26, 2009 11:51 pm

Posts: 1538
Kev UK -
Yep, that too...


That overflow tube is also a drain tube. For winterizing storage, or service work. You just go at the CV carb-bowl from left side of bike motor (between the jugs) with long straight blade medium screwdriver.. Bowl will have a slotted screw. Just open it a 1/4 -1/2 turn & put tube in a can to collect draining gas. Once bowl is emptied, then close screw..

That should help you avoid this situation again..

That is one of the perks of a pre '99 CV carb..

Post Sat Feb 28, 2009 4:58 pm

Posts: 250

I have taken the CV carb apart so I can rebuild it. I have a factory manual and a aftermarket manual. The after market manual says not to clean carb body in carb cleaner and not to remove disk throttle and related parts. Says carb cleaner will ruin seals in disk shaft. Do you leave disk and shaft in body and clean body by hand (with kerosene?, I am low tech) or do you take it apart. Looks like it would be a bitch to take apart. I am going to clean up and put rebuild kit with gaskets and needle value in. The bowl and needle valve was not gunked up, maybe gas was evaporated out of bowl and float stuck in down position. Hope that is what it was. I have done bunch of Linkerts, but never a modern CV. This will be an adventure. Sleeper, I know you are the CV guru here. Any help appreciated.

Post Sun Mar 01, 2009 1:33 am

Posts: 1538

guru, naw, but I did stay at a Holiday Inn the other night.. :wink:

I would not soak that in carb-cleaner. It will EAT the seals out..

If you have no weeping outside at the throttle shaft on either side that the butterfly attaches to. Leave it alone..

But if it is weeping outside there then new seals should be used. Replacement is not difficult. The return spring is something to be mindful of tho.. I never soak these carbs.. I just spray em with carb-kleen & blow dry..

Kerosene by hand is fine..Don't use Ur parts washer fluid. That's dirty.. Then blow out all passages thoroughly..

Put your float in a pan of liquid & see how boyant it still is..Should be fine. Correct Float level is important.

Be careful if you still have the black plastic elbow for gas inlet line, they break easy.. But replacement in Brass elbow is always a good up-grade, (if needed.) If you have to change this shoot me a PM. It's not hard, but kinda tricky..

The shut off needle has a tiny wire clip on it looped over a tang off the float. Make sure you see how it attaches so you can put it back correctly, + it's in the Book.

At the float hinge, the carb body will have an embossed arrow pointing which way to push out the hinge-pin.. & re-assemble accordingly..

If you should need any hard-parts, I have them..

Take yer time, it'll be fine.. Be sure to use a new carb to intake rubber seal ....I use liquid dish-soap (Dawn) on this seal, so assembly is easy & doesn't damage the rubber, & you can safely move carb around during re-assembly. First heat will dry out the soap..
Also might be good time to replace the Vacuum line from carb to VOES switch. Careful on the switch,it is plastic also..& likely brittle.. I usually use a razor to carefully slice line at switch to aid in easy removal..& dish soap to ease install.
Perfect time to replace Gas Line also..

For more detail should you need..shoot me a PM.


Post Tue Mar 03, 2009 6:45 am

Posts: 250

Hey Sleeper, I tryed to PM you but may have done it wrong. I do need to know the secret how to remove the plastic fuel inlet line. Mine is cracked and I need to replace. Thanks, Buster.

Post Tue Mar 03, 2009 10:31 am

Posts: 1538

I replied to your PM on 3/01, check your message inbox here..

Plus I just emailed you with same info...Subject line: CV plastic elbow removal

You should have it by now....

Post Wed Mar 18, 2009 5:35 am

Posts: 250

Sleeper PM'ed me through the rebuild on my CV carb and I finally got it back together this week. The bike runs great. I bellieve Sleeper is the CV guru on this board. This was my first CV rebuild and I really appreciate his help. Thanks again, Buster

Post Wed Mar 25, 2009 11:14 pm

Posts: 1538

Glad your bike is up & going again...

Post Sun Nov 29, 2009 12:57 am

Posts: 113
Location: Plattsburgh, NY, USA

Sorry BUT it Sounds like New Carb Time!
HD CV carbs up to 1991-1993 [I can't remember] had a loose slide fit where the float pin goes thru the two cast-in "towers" that support/hold the pin. Over time/high mileage Harleys shake the bejabbers out of the carb causing the steel pin to egg the holes in the softer aluminum tower holes. This causes the float to setup anwhere it wants causing the float needle to be off the seat. Gas flows into your oil diluting/contaminating it causing all sorts of problems. I don't think HD ever had a Recall on the bad CV carbs but I know the later 1992-1993 and newer carbs were changed to a tight "drive" fit on the float pin to hole fit. It's easy to see if your carb is FUBARED, take the float out & reinstall the steel pin and see how much slop you have between the pin and mounting holes. Usually the holes are "egged" out a bit. A friend"s fix would be to support the delicate aluminum hole tower with a piece of lead or brass and smack the hole with a hammer & sharp punch next to the edge tightening the fit. I personally would just toss the carb away and buy a S&S Super E. They'll pass rocks and last forever. They just don't give you the good Milege that the CV does.
Always check for sloopy float pin holes when buying carbs at swap meets. All HD CV carbs had a factory Part Number on them. If the Part # ends in a # earlier than -92 or -93 pull the bowl off andcheck the holes before buying the carb. Swap Meets are where all the F'ed up HD parts go!!

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