1983 Big Red

[alcend]

Hello all,

Thank you all for the great posts that have helped me through the years to fix my bikes.

I now come to you all with for help.

I have an 83 Big Red and I cannot fix the sputtering problem. It will start with no problem and idle but upon acceleration it begins to sound like a really bad Harley (no offense). If I dare try to put it in gear it is like asking a turtle to race me, it doesn't go anywhere.

I've read a couple of posts regarding the carb and but it has a new carb in it. I have a guy who is leading me to believe it is the valves and would like to pull the engine apart and redo.

If anyone can give me some advice that would be great.

Thank you in advance

[tri again]

Hi and welcome,

1st thing to do is a deep breath.
No reason to tear it apart just yet.
I like to get them to run at Least enough to run through the gears
and make sure everything works before putting $$ into it.

Can you check compression somehow?
gauge or will it blow your finger off, does it seem like it has good resistance to pull starting?

Is it new to you?
Have you ever heard it run correctly?

New carb may not be right and the harley reference is welcome
if it sounds like saying, "potato, potato, potato" you're ok but that's their 2 cylinder.

anyway, you say it starts and idles?
good so far.
old gas?
I think there's a spark advance plate under the cover on the engine head that says 'cdi' usually packed with rustdust.
It's wants to rotate and has 2 tiny pen type springs that can break and throw off your timing.
Yes, not a bad idea to check valve clearance for sure or nothing else will fall into place.

Air intake leak?
With it idling, spray some carb cleaner around where the carb mounts and see if it changes the idle.
do NOT use brakleen, it burns into phosgene gas and can kill you.

I've also had some magical results by nipping the last tiny bit off the plug wire so the spark plug cap has some fresh copper to bite into.

Also a great idea to clean ALL electrical connections, especially grounds.
I know I know it's a pain but then you can eliminate issues.

The service manual wiull give you values and how to check stator output and pulse sensor etc .

can you lick on:
service manual

Pls keep us posted.
sounds like your ready for success.

[tri again]

ps -
try the search key for anything you can find about 'poor running 200'
or 200 won't run right' or something like that.
You'll get tons of pages of great info with one click.

[barnett468]

Hello alcend


Here's a couple additional questions in addition to those previously asked. Answering ALL the questions will help others to help you better.


GAS - Did you add new gas to old gas, if so how old was old gas?

Turn on gas valve to fill float bowl then turn valve off, drain gas from float bowl into narrow glass via drain screw, what color is it, any sediment, any small clear bubble at bottom [water]?

If gas is apple juice color it may be either old or colored by rust in tank, old gas can cause your bike to run exactly the way it is now and the rust contaminated gas is bad for your motor and can affect performance also.

VALVES – If the valves were bad enough to cause a heavy sputter it would most likely not idle smoothly but check clearance anyway. See if rockers go up and down around 3/8”-7/16”, if they don’t you have a flat cam lobe but since it starts and idles fine this is unlikely but check it anyway also.


Make a video like this if you can and paste the youtube link to it here.

http://www.youtube.com/watch?v=rtiVl7VrF-Y&feature=youtu.be


AIR LEAK – The fact that your bike idles fine virtually eliminates the possibility you have an air leak but it’s fast and easy to check for so I would do it as tri again suggested


I suggest you do an air leak test by gently spraying [using the long narrow nozzle] FLAMMABLE [not water base or chlorinated] brake cleaner around the intake boot at the head and carb mount while the bike is idling. If the idle goes up noticeably you have an intake air leak. It is more volatile than carb cleaner and therefore detects small leaks more easily.



With it idling, spray some carb cleaner around where the carb mounts and see if it changes the idle. do NOT use brakleen, it burns into phosgene gas and can kill you.


Hi Not sure I read everything correctly but I remember a thread about using brakleen to clean stuff that will be torched or welded. I personally can't seem to live without it.Apparently it turns into phosgene gas in the presence of flame which can cause permanent lung damage with the smallest of exposure. I've heard that carb cleaner can work to check for intake leaks but not sure about that either. I read the can after I read that article and the warning is very vague.

http://www.3wheelerworld.com/showthr...light=phosgene


Flame is not required to break down tetrachloroethylene to a point at which it will produce a very small percentage of phosogene as a byproduct only heat is.

Thermal decomposition of Tetrachloroethylene creates phosgene ie heat + UV + TCE => some phosgene.

“Tetrachloroethylene began to decompose near 400°C and vigorous pyrolysis occurred over 600°C. Complete decomposition was observed at 800°C. Hydrogen chloride and phosgene were detected as decomposition products, presumably because chemical reaction occurs between tetrachloroethylene and water contained in tetrachloroethylene.

Chemosphere

Volume 26, Issue 8, April 1993, Pages 1507-1512”


Tetrachloroethylene is NON flammable and is used in NON flammable chlorinated brake cleaner.

Flammable brake cleaners are NON chlorinated [no tetrachloroethylene].

I still use brake cleaner but only the flammable kind [since I don’t see much point in spraying non flammable substances into a motor to check for an intake leak], just don’t spray it on ex pipes anyway and be careful NOT to inhale fumes of ANY cleaners. Flammable Carburetor cleaner may produce more harmful fumes than NON chlorinated flammable brake cleaner however I don’t know, further research is needed.


Non chlorinated, flammable brake cleaner, for use when testing for intake leaks.

http://www.crcindustries.com/ei/product_detail.aspx?id=05084

[alcend]

Thank you guys. I am going to try everything you all just mentioned and get back to you with the results.