82 850G Starting Problems

[BeerMonger]

I bought this bike late last year. It took a while to start, but did eventually.

Over the winter I:
Soaked the carbs, replaced all rubber with the o-rings kit.
Bench sync only.
Valve adjustment.
New carb boots to engine c/w o-rings.
New carb boots to airbox.
Sealed the airbox.
Replaced petcock.

I primed the float bowls (fuel ran for 30-60 seconds on PRI).
I have spark, I have compression.
Bike doesn't start, or even pretend to start.

There are 4-to-1 pipes on it, don't know if it was re-jetted. I would like to get it started before investigating rejetting (I looks for stock pipes over winter but did not find).

What do you suggest I do next?

My neighbour suggests pulling the airbox and using a spray bottle to spray fuel direct through the carbs, but I wanted to ask you guys first.

Thanks in advance for any direction.

 

[hampshirehog]

Try dropping a thimbleful of petrol in to each plug hole - easier than pulling the airbox rubbers off. Plus check you've got your plug leads going to the right plugs.

 

[Steve]

Also make sure your idle mixture adjustment screws are out far enough to let in enough fuel (three turns should be a good start).

I have also had a hard time starting, only to find that the master idle speed screw was WAY off.

Don't use the throttle to try to give it just a little gas, use the idle speed control.

Squirting "fuel" into the intakes would not be so bad, but it's awfully hard to do, then put it all together in time to take advantage of it.

Whatever you do, DON'T use any starting fluid. That stuff can get nasty, QUICKLY.

.

 

[Guest]

Install new plugs..

 

[BeerMonger]

Thanks for your suggestions, I tried them all.

I turned the fuel mixture in all the way gently, then backed them out 3 full turns. (I also tried them at 2.5 and 3.5)
I installed new plugs. (I got spark)
I put a thimble full of gas in the cylinders. (1 & 4 only because of ease)

The bike turns over but no starting, and no firing.
Any suggestions?

 

[Mercaholic]

Thanks for your suggestions, I tried them all.

I turned the fuel mixture in all the way gently, then backed them out 3 full turns. (I also tried them at 2.5 and 3.5)
I installed new plugs. (I got spark)
I put a thimble full of gas in the cylinders. (1 & 4 only because of ease)

The bike turns over but no starting, and no firing.
Any suggestions?

Were the old plugs wet?

If so, go with your neighbours idea and spray some ether or 'quick-start' into each carb with the airbox off. Note NOT too much!

Crank the throttle open and see what happens

 

[Skateguy50]

Getting that first crank over can be hard, if you have been going at it a while the battery might be low on power. I got mine over with a boost from the car battery, just make sure the car is OFF if you put the cables on the bike battery to give you some more crank power.

The comment on the idle adjust is also big, and check that the "choke" is working. For me sometimes after a few tries I need the choke in the middle to get it to turn over. Just give it a few cranks at a time then wait and try again. Get a beer, wait a bit more, then try again. Something will get it eventually but try only adjusting one variable at a time and think it over another beer and try again. After a few beers you should get it, just dont take it for a spin if it takes more than a 6 pack

 

[teddux]

If your idle screw/knob setting is opened too much would cause this.
Set idle screw all the way closed (out) and try again with different choke settings.

When it sounds like it wants to start, open the throttle gradually...

 

[BassCliff]

Hi,

Are you getting enough spark? What is the voltage at the coils? Ideally you should be getting 12v but these old wiring harnesses, because of corrosion, can degrade that to 10v or less. If cleaning all of the connections in the entire wiring harness is not enough then the coil relay mod may be in order. Keep us informed.


Thank you for your indulgence,

BassCliff

 

[Steve]

... Just give it a few cranks at a time then wait and try again. Get a beer, wait a bit more, then try again. Something will get it eventually but try only adjusting one variable at a time and think it over another beer and try again. After a few beers you should get it, ...

I just can't imagine that adding beer to the gas would make it start any easier. After all, there's not that much alcohol in there, it's mostly water.

On the other hand, I must say that NO starting problem has ever enticed me to the consumption of alcohol.
Personally, if I can't get it started with a clear head, how could I possibly get it running after drinking "a few"?

.

 

[BeerMonger]

Hi,

Are you getting enough spark? What is the voltage at the coils? Ideally you should be getting 12v but these old wiring harnesses, because of corrosion, can degrade that to 10v or less. If cleaning all of the connections in the entire wiring harness is not enough then the coil relay mod may be in order. Keep us informed.


Thank you for your indulgence,

BassCliff

BassCliff, what points do I use to check the voltage at the coils? Coil(+) to ground on bike? And Coil(-) to Battery(+)?

Thanks in advance.

 

[BassCliff]

BassCliff, what points do I use to check the voltage at the coils? Coil(+) to ground on bike? And Coil(-) to Battery(+)?

Thanks in advance.

Hi,

Measure voltage between the Orange/white wire on the coil and the battery negative terminal. Here are some great tips from Mr. Matchless:

Testing The Ignition System


Thank you for your indulgence,

BassCliff

 

[BeerMonger]

I practically live on your site, I'm embarrassed I over-looked this page.
I will check voltages and resistances tonight. I also see now that my coils are not stock.

 

[BeerMonger]

The voltage across the coils is just 1v under my battery voltage, so I think I'm good there.
I just plugged the vacuum port on the carb that runs to the petcock. (I put my tank on a shelf with a 2' fuel line.)
I backed out the idle set screw all the way out (throttle closed), and tried variations of choke.

I heard exactly 1 faint puff, which is the closest I've got to starting. I've got the charger on it now.

edit:I just checked the resistance of the 'igniter' side of both coils and they read 3.8 and 3.9 ohms. Which is higher than the 2-3 ohms typical of stock coils. Can this 25-50% out of spec range prevent starting?

 

[BeerMonger]

Just wondering if anyone has any more insight into my starting problems.

 

[rustybronco]

Plus check you've got your plug leads going to the right plugs.

Have you checked this yet?

I know you turned it on prime for 30-60 seconds, but did you check and see if you have fuel in the float bowls.

you also may want to make up a tool to check the fuel level(s) externally.

edit... what is your outside air temp at?

 

[BeerMonger]

Have you checked this yet?

I know you turned it on prime for 30-60 seconds, but did you check and see if you have fuel in the float bowls.

you also may want to make up a tool to check the fuel level(s) externally.

edit... what is your outside air temp at?

Yes, my plugs leads are right.
I drained all the float bowls, and reprimed them. This allowed me to prove there was fuel in the bowls, and witness the fuel flowing into them when I reprimed them.

I have not built the external fuel level tool.

My temp is about 10C (50F). (heated garage)

I managed to get a couple of little burps from it last night, which is the most success I've had in a week.

 

[rustybronco]

My temp is about 10C (50F). (heated garage)

I managed to get a couple of little burps from it last night, which is the most success I've had in a week.

Every (well almost) correctly timed engine that I have worked on, if it had "sufficient" spark, in the correct order and you added fuel to the combustion chamber it would fire.

check and see if the negative sides of the coils are connected correctly.

have you taken any compression readings as of yet? if so, what were they?

how well did it run last year? did it keep running on it's own?

do you have a timing light?

if needed, we will go onto checking the cam timing.

 

[BeerMonger]

I've taken the connections off, cleaned them, and put them back on.
I have only done the 'finger' test for compression, no readings.
It ran like crap last year, but did keep running on it's own.
I don't have a timing light.

I appreciate the help thru start-up. It's been a fun project, but would be more fun with a running engine.

I did a visual inspection only of the air filter, I didn't clean it, because it didn't look bad. How should i clean this? I've never done it before and I've read about different approaches and chemicals.

 

[BeerMonger]

I'm embarrassed.

The bike just back fired twice after grocery shopping. So I swapped plug wires 1&4 with 2&3. It fired up immediately. I'M SUPER STOKED!!!
This is my first build ever, and it feels very satisfying to have a running engine after tinkering with it over the winter. Thanks for your help and suggestions. I still have a long road in front of me, but I have a running engine!