funky timing light

[ISAMEMON]

so a friend swings by and tells me he did a valve adjust, set timing and syn carbs, and his performance and mpg went down hill.

so I take it for a ride, man gutless for a 89 R100rs, gutless.
I did not check his valves, nor mess with the carbs, but did check his timing

where he set hsi timing with his light does not agree with my light.
he set it so the z is lined up, with my light the z is all the way at the top of the wiindow, just barely visible

wonder whos light is right

his is an acutron ?
mine a old craftsman

so we set it with my light, havent heard back from him since this afternoon , when he left
I guess too advance would effect power and mpg. but it did not ping or rattle like a machine too advanced

[20774]

I think you need a third timing light...I think AutoZone rents them. Not sure where you're getting the power for the timing light. I've heard that you shouldn't use the bike's battery but rather use another vehicle...like put the bike near your car and use it's battery. I'm not sure it really makes a difference but worth considering.

[lmo1131]

... what's a timing light?!?

[toooldtocare]

Did you both use the same plug for the trigger? I have seen that much difference between the right and left plug, probably from chain stretch. Even then, I do not think that little difference would make too much difference in the way the bike ran, but could cause it to ping.

[lkchris]

In 40 years of owning cars and bikes have never needed a timing light or to adjust timing.

If it's good once, it's good until messed with.

[ISAMEMON]

Did you both use the same plug for the trigger? I have seen that much difference between the right and left plug, probably from chain stretch. Even then, I do not think that little difference would make too much difference in the way the bike ran, but could cause it to ping.

yes we both used the same plug, left side next to timing hole

exam of plugs were black, like running way rich, however in the begining of the summer he did a partial rebuild of carbs. And all was good. He said he was getting over 40mpg, now he says hes getting about 30
carb overhaul
partial meaning the only thing not replaced was the floats and float needles and the lower jets
it got new diaphrams, needles and seats, idle screws, new rubber between carbs and heads and horns, all o-rings, fuel filters and air filter.
I would think a filter issue would make it run lean, other then maybe a plugged airfilter, but they are all new
I could see one float go bad making one side run rich, but both plugs were equally black, bike does not smoke
dyna coil, icu and heat paste last summer


side note, the bike also has nearly 75k on it, and the left cylinder is down by almost 15 pounds, and comes up wiht oil . it has been this way for nearly a year, so its not a new issue that has crept up

just trying to get him going, he has a road trip coming up, and it is gutless, he is reluctant to laod it wiht gear and hit the hills

hes picking up new plugs ( BP7ES) and we are gonna check compression again today/tonight
( Ive been running BP6ES in my R80RT, I thought he was too, he said hes running what he is supposed too ? according to motoelectric)

[toooldtocare]

Choke on too? May be something really simple like a sticking choke cable. Good luck, and let us know what you find.

Wayne

[ISAMEMON]

Choke on too? May be something really simple like a sticking choke cable. Good luck, and let us know what you find.

Wayne

BINGO , Wayne you win a cookie
when steve was balancing his carbs he decided to take the slack out of the choke cables.
Soooooooo, what you do that for..........shoulder shrug

I put a lot of slack in the cables, took everything to ground zero and balanced the carbs and adjusted idle jets. Then took some of the slack out of the cables
bike wiht timing set with my light, carbs balanced, and choke cables not tight, all seems well.
obviously he must have taken out enough slack to just have em kicking in.
On his winter list, new cables, as they are all getting stiff and rusty and one is starting to de-strand

put in the new plugs, did not bother doing a compression check

[toooldtocare]

Glad it is up and running.