starting issues

[Ariel-KH-500]

Having problems starting the bike when its stood for a few days. When trying the start the bike I turn on the fuel about 5-10 minutes before trying it turns over ok and for about 4 presses of the button it makes no attempt to fire, after more presses of the button it fires once this then happens a few more times until it starts to run but very lumpy eventually it will chime up on all four cylinders and run. When ridden it performs as it should and when left for a few hours it stars as it should. So the jobs that I have done so far are Timing checked, valve clearances checked, balanced carbs, fitted new battery, checked petrol tank fuel filter, also only E5 fuel been used. I've now removed the carbs and have stripped them ready to ultrasonic clean them upon initial inspection they look spotless. The bike has only done 13,000 miles from new, I will post again in a few days to let you know if the cleaning was a success but in the meantime any ideas  or advice gratefully received . PS bike stored in my dining room during the winter after draining the tank and putting fuel solutions storage fuel in it and running it through the carbs bike started ok after winter lay up.

[McCabe-Thiele (Ted)]

My 400 was the same when I first had it running after 10 years of being in POs garage.

Turned out to be low compressions, all were even but not enough.
Try the Easystart spray test on the air box.

[Oddjob]

First off why turn the fuel on so early and leave for so long? It could be the problem or part of the problem. There should be enough in the float bowls to start the engine, unless you’re one of those that turn the tap off a few minutes from home and run the bowls dry, not knocking that practice but would go so way to explain the tap turning on thing. If the float levels are wrong it will start to flood the cylinders, that could mean it fails to start or it runs lumpy for a while until it’s burned it off.

How are the plugs looking? Are they new? Odd question but what make are they? Reason for that is there are a lot of fake NGK plugs around and a mate of mine had a similar problem on his Harley. He kept saying the plugs are new it’s not them. I kept telling him to refit the old ones and see if it was ok or the same but he was stubborn and stuck with his new ones. Of course they turned out to be fake, bought from a motorcycle shop btw not eBay. A month with no bike just because he thought new meant they couldn’t be the problem.

I’d really check the idle jets when you remove them, hold them up to a strong light and see if they are blocked.

Report after that or when others ask questions.

[Ariel-KH-500]

It dose not make any difference if I just turn the fuel on or turn it on early the problem is still the same, its probably an old habit riding my old classic bikes as if they have stood for a few days the old Amal carbs tend to evaporate.. spark plugs are new and purchased from David silver along with air filter and oil filter. Just waiting for cleaning fluid to arrive will post results when carbs have been cleaned refitted and balanced

[K2-K6]

If float valves (controlling fill from tank) are a OK, then it shouldn't matter how long the tap is left on prior to start.

As most things are checked, and carbs cleaned too, then if it persists a check of compression psi would be helpful in establishing whether anything is out of range there.

[Oddjob]

The point I was trying to make Nige was that IF the float needles were leaking or the float height was incorrect then that 5 min wait could be making things much worse or even be the source of the problem.

[K2-K6]

Yes agree with your thoughts Ken, it should show with wet feet though  out through the overflow tubes, if they are letting by.

Interesting to hear if there's any improvement after the checks done and work on carbs.

[Ariel-KH-500]

When I posted regarding my starting issues I said that I would report back so here goes. Carbs taken off bike completely striped the carb bodies have been ultrasonic cleaned along with all the jets. The carbs then reassembled new O rings and slides set up on the bench, then refitted to the bike and all set up with vacuum gauges, bike started ok and ran fine, after leaving it for a few days went to start it and just like before turned over 2/3 times then fired but didn't start after a few more attempts it fired but rather lumpy the chiming in on all 4 once running it runs fine. I'm at a loss to think why as if I try to start it after a few hours it will start fine its only when it has not been started for a few day any ideas Kevin

[McCabe-Thiele (Ted)]

Just my thoughts,
A retarded engine can be slow to start, is the timing correct for both 1/4 & 2/3?
Check no air leaks between engine & carbs.
Do you know the compression readings?

[K2-K6]

A couple of things to try in helping analysis and find out effect.

1) spray E-Z-start into airbox prior to cranking and see if there's any change to how it initially fires when cold.

2) cover airbox entry (thick rag or similar) and crank with kill switch off, just for a few 5 second bursts, then remove rag, switch on and try to start. Again, to observe if there's any immediate change in willingness to fire when cold etc.

[TrickyMicky]

Easy Start----- YEUK!!-- The work of the devil.  The knocking noises I've heard over the years from enthusiastic use.   

[McCabe-Thiele (Ted)]

Easy Start----- YEUK!!-- The work of the devil.  The knocking noises I've heard over the years from enthusiastic use.

Especially on a Diesel Engine.👍

[McCabe-Thiele (Ted)]

I'm making some basic assumptions such as full choke with no throttle on cold start.

[K2-K6]

Easy Start----- YEUK!!-- The work of the devil.  The knocking noises I've heard over the years from enthusiastic use.

Its just basic testing to gauge effect. What it can do is show there's impaired or low flow from idle fuel circuit that's supposed to be supplying at this juncture.

Improvement with "assistance" would indicate that the idle jet circuit needs further inspection ...... which no-one wants to do on these 

The covered airbox test too, if there's notable improvement then again it suggests that the increase in inlet vacuum is more effective in pulling fuel up through the jets, initially.

[Rayzerman]

Many seem to have difficulties with these 350's.... I've had my own share of grief with getting these carbs bench sync'd then set properly on the bike.... by chance has anyone decided to go up a size on the idle jets?  And of course, did it help or hinder?