'78 Will Not Start With Choke

[Forde]

Hello again!

I have a 78 400E which is being a handful to say the least. Right now, the bike refuses to start with the choke on at all (or the enricher, whatever you want to call it) and requires a good amount of kicking and swearing before it fires up. Once started, if I attempt to put the choke on to warm up the bike, it dies almost immediately.

The bike has its stock jets from what I can tell, and for the purposes of running it right now everything is stock.

Has anyone experienced this before or have any tips for dealing with it?

Thanks!

 

[spectra]

Have you went through the carbs yet? Cleaned ? Fuel bowl levels checked ? Valves adjusted and timing good ? How are the boots ?

So many things need to be figured out.

 

[Forde]

All points I should have addressed in my first post, thanks for reminding me Spectra.

Carbs have been cleaned multiple times with barrymans dip, a high e guitar string, and regular spray cleaner. Floats have been set to 32mm. Timing has been set according to a wonderful video I found on youtube. Boots are new as of last season, and I went with a normal gravity petcock instead of the old vacuum one. I sealed up the right hand boot vacuum barb with a bit of burned and crimped airline tubing from a fishtank (Is there a better way of sealing this?)
The only thing I have yet to do is gap the points, which I should be able to complete in the next few days, but I think that it wouldn't be strictly related to being hard to start, right?

I recognize that it's anyone's guess given that nobody is with the bike except for me, but doesn't this sound like a running too rich problem? It just seems to make sense to me that:

Hard to start but runs fine without choke + backfires and dies when choked = running too rich initially

 

[xschris]

Brass floats are 26mm. If you dipped the carbs did you remove all the rubber parts first? Everything should have been disassembled before you dipped. That includes the butterfly shaft seals. Carbs synced with manometer? 77-79 style carbs are known for having broken off idle air mix screws stuck in carb bodies. Post some pics of the bike so we can see what your working with.

 

[NewHavenMike]

Those were my first guesses as well... Some of that chemical crap is no good for rubber parts, and a lot of times, people crank down those idle mix screws and the tip breaks in the carb body. The carbs need to be in pieces. Its a real pain but its the only way. You should order new screws for the throttle shaft butterflies and the seals right now lol.. Get Lock Tite for the butterfly screws too. Take pictures so you can remember and don't mix parts together

You can buy the rubber caps to seal the vacuum nipples on the boots anywhere, theyre common. Auto parts stores should even have some caps in the vaccum line section.

Make sure you add a filter on your fuel line too if you haven't already. The filter on the petcock is not enough. The filter I use is a clear conical sintered brass one.