hard starting

[cobra407]

I have a hard-start issue especially when cold. I close the choke 1/2 way and it usually kicks over pretty easy.... and then really hard to get it going. open choke... close choke... bla .... bla.... -- i end up running the starter for sometimes 45 seconds. I have noticed there is a "sweet spot" when opening the throttle part way that can be found when turning it over with the starter... if i keep the throttle there it eventually gets going

Once i get it running it runs great.

Im thinking time for carb re-build? any other suggestions?

[Bob_Roller]

I had a starting issue with my '81 R65, at around 55 F,  hard starting on first 'cold' start of the day, after that, it was fine .

I had a bad ignition coil, the primary circuit had .7 ohms when it should have 1.5 ohms .

New coil solved the hard starting .

I went through the carbs, cleaned them out, even though I saw nothing out of the ordinary .

I would check everything out and do a thorough cleaning before replacing any parts .  

Check the 'choke/enricher', cables for adjustment, etc....... .

My problem surfaced, when 10% ethanol was added to the fuel supply here in the Phoenix area .

[Barry]

My bike starts almost instantly on the button.

.......except when it doesn't.

When it doesn't is very rare like 1 in a hundred starts and it's usually because I got the choke setting wrong. Then it sure can be pig to light up. Half choke isn't enough and full choke seems to flood it. I've found one of the the best things to do is precisely nothing while counting to ten.

The choke is a bit of a crude device (on my carbs at least). I have never encountered a temperature when full choke wasn't grossly too rich even at -10 deg C. It got improved and developed with more progressive holes in the disc over the years so maybe this method shouldn't  be necessary on later bikes. It works for me at moderate temperatures when the gross over enrichment of full choke is too much. With the choke on full and the throttle closed just blip the starter momentarily (or kick it over). This draws some fuel into the inlet tract. Then fully close the choke and it start as normal. Bizarrely half choke wouldn't do it under the same conditions.

[Bob_Roller]

Starting technique is quite important .

If you hold the throttle open a bit while cranking the starter, it's pretty common not to have the engine fire .

Every bike can require a bit different technique .

This technique seems to be common among owners, turn fuel on, I usually turn the fuel tap on, then put gloves on, etc..., 'choke' in the full on position, sometimes it springs back from the full position, so you may need to keep it at the stop  with your finger .

Push starter button and don't not open the throttle, until you get one of the cylinders firing, then open the throttle, I usually give it a quick twist to about half throttle then let it close on it's own .

My bike routinely gets left out at work for 16-18 hours in temps that are in the upper 30's-low 40's F ( a cold 'winter' day in Phoenix!!!), and I never have an issue with starting .

A good battery, left on a battery tender when the bike isn't being ridden isn't a bad idea either, if you can do it .

[tvrla]

Forty five seconds is a long time to be cranking the engine! It's much better doing short blips than one long grind.

Since it's the choke's job to start the cold engine, that's the first place to look. Make sure the cables are adjusted so the mechanism moves the full distance.

The enrichener (choke) bodies tend to loosen up over time, so make sure the four screws are tight. If they've loosened, there's a good possibility the gasket got sucked in causing an air leak. If there's an air leak, there won't be any SUCKing action.

Just like carburetors have main jets and idle jets etc, the enrichener has a jet in the bottom of the float bowl. It's in a well and the enrichener pick-up tube fits down there slurping up the fuel. Make sure that's all clean and free of cluge.

One other thing - if the float bowl gasket isn't sealing around that well, suck will be reduced and the choke won't work very well.

[rwait]

Also check your valve clearance.  

On a trip this past Fall to the Northeast USA, Montreal, and back to Chicago, my bike began to stall when coming off the highway to a stop sign, then stalling in traffic, and it got progressively more difficult to start each time.  

I'll spare everyone the long details of my experience except to say that I met a couple in Prescott, Ontario that were the most amazing and gracious people I have met...both BMW riders too.

After checking out several different potential sources, we checked valve clearance and found that the intake valve on the left side was extremely tight.  After a quick adjustment, the bike started over in one quick push of the starter button, I headed back towards home the next day...and the R65 has started on nearly the first push of the starter button ever since.

RW