84 iron head runablity

[SFONT911]

Just a follow up to the hot start problem. i have checked everything down to ridding to warm her up then parking and let her set for bout 20 minnn. As usuall crank no run , pulled the modual out cold pack it chill it down, reinstall line up marks still same crack no run. repeated the same prosses with the coil but replaced it with a new one at that time. my next thing to do is heat up JUST the carb. with a heat gun. if it dont start WHAT then replace the the whole carb with a new rebuilt. this is killing me, by the time i am finish type'n this it will fire up and run like nothing is wrong.

[Flame_Retardent]

Try retarding your timing just a bit, and see if that helps

[pittsjock]

I hate to see people randomly replacing things - just a waste of money.

The problem seems to be caused by the motor heating up.

Start by warming it up and then shutting it off. It doesn't start, right?

You can check for spark by pulling the plug and cranking it over a few times with the plug resting against the cylinder. You will see spark or not.

If you don't have spark - then you need to figure out why. Coil would be my first guess, but since you have replaced it, doesn't sound like that is the problem. I would hotwire the machine and see if I could get it to run to prove the problem was wiring (as opposed to coil).

If you have spark, then the problem is either fuel or compression.

Pull the air cleaner.

Grab a can of WD40 and spray a little bit into the carb while you are cranking. The motor should fire/pop/run for a second. If it doesn't - then your problem is compression, not fuel.

If the motor fires with WD40, then you need to track down the fuel problem. It sound like a supply issue. Pull the fuel line and make sure gas is flowing freely from the tank. If it is, pull the carb apart and make sure nothing is clogged. I would buy a gallon of carb cleaner, disassemble the carb and soak it, install new gaskets and try again.

If the problem is related to compression, report back.

[SFONT911]

Thanks Pittsjock,
The puzzleing thing is that it runs very well hot and cold. i can shut it off after ridding for an hour... stop shut her down and a after 1 or 2 minn it will fire and run but if she sits for 20 min or longer crank no run pop out carb and pipes. i was thinking that the battery heats up at this point and does not crank the motor oveer fast enough. later today i will still try hot card test and look at the cranking amps of the battery also

[iNSaNeSHaNe]

I'm with Pitts do some quick checks. first is get it hot and take off the air filter then get yourself a spare plug to use for checking spark or do like me and just hold the wire end and spin it over lol that always lets ya know in a hurry if its firing. wait till its not starting give it a spray of FLAMMABLE carb spray in the carb with the throttle open. then just turn it over see if it starts and dies. if so fuel is the culprit. if it doesn't start then look at the fire . pull off a plug lead and check for spark. if there is spark then next pull a plug and do a compression check. It's a long shot but someone may have the valves too tight and as the engine sits all the heat build up could make the pushrods expand and hold the valves slightly open until they cool off again. I've only seen this a few times and they acted similar to what you are saying with the popping out the intake and exhaust. with those the ppl said they could push start the bike. I never varified that tho.

[pittsjock]

Originally Posted by SFONT911

Thanks Pittsjock,
The puzzleing thing is that it runs very well hot and cold. i can shut it off after ridding for an hour... stop shut her down and a after 1 or 2 minn it will fire and run but if she sits for 20 min or longer crank no run pop out carb and pipes. i was thinking that the battery heats up at this point and does not crank the motor oveer fast enough. later today i will still try hot card test and look at the cranking amps of the battery also

That is strange!!!

I think you need to be systematic - like a scientist.

I don't think the battery theory is valid.

Run for an hour. Let cool for 20 minutes.

1. Check spark
2. Check fuel flow at carb.

This sounds like a vapor lock problem. Take a look at the fuel line routing.

[iNSaNeSHaNe]

again Pitts right on with ya there my 85 had an extra fuel filter on it NOT ANY MORE !!!!!
it would vapor lock after I went into a store and came back out wouldn't fire turned out the fuel filter was the culprit up above the the heads. just think simple it usually is.

[SFONT911]

After restting the timming new battery, and resetting the mixture screw,i was hot on the heals of fixing the problem .. the dam thing somehow Jumped into gear from neutral as i was cranking it over(standing on the right side of the bike mind u) and now has a knock noise from the primary chain/ clutch area. WTF

[Flame_Retardent]

Nooooooooooo!

Sent from my ADR6410LVW using Tapatalk 2

[SFONT911]

is there any good instructional videos out there on how all this comes apart?