White smoke and difficult starting

[Mike the Bike]

Hi all

I recently spent a lot of time and money (for me), doing a top end overhaul, and a new timing chain. At the same time, I tinkered with, and cleaned, the carburettors. When it was all put back together, it seemed generally fine for a short while (although the carbs still need a little more 'balancing'). Now I do have a problem. When I start up in this cold weather, I have to spin it for a long time on the starter, before I get more than 1 cylinder to 'catch on'. The choke is full on, but once started, it only needs the choke for a very short time. The choke doesn't seem to increase the revs, which I thought it should, to an extent.

Also, huge plumes of white/grey clouds appear from the exhaust, and this takes a long time to clear. I know they tend to smoke a little on start up, but this seems way too excessive. Once it is warmed up, it settles to a steady tickover, and runs smoothly through the rev range (although it still smokes a little).

I think it is something to do with the carburettors, as Ive checked the valves for adjustment, and the plugs spark OK. In fact, I think it may be something to do with the choke mechanism, but that's all i am guessing at for now.

I need someone with some experience of these symptoms to point me in the right direction as to the cause of the very poor starting, and the huge plumes of smoke. Any advice gratefully received !.... Mick

by the way ... it's a R80GS para

 

[2gses]

smoke

check the timing.

 

[Mike the Bike]

Thanks - I'll do that. I think it's about right, but I'll have another check tonight

 

[(RIP) Proff]

It's an old fashioned choke. [mixture enricher]
so does not normally raise revs like on Fuel injected bike...
I'd take a good look at your coils, as they will favour one side if 1 is weak...

When you "overhauled" your carbs I trust you stripped and rebuilt the choke part
If so, do a DOUBLECHECK on it being assembled correctly

DAMHIK

Also, White smoke in winter usually means you're burning off the condensation in yer pipes..... they all do that sir

 

[Kenny]

Very cold weather will cause white clouds of vapour from the exhausts. Is the engine getting hot enough on normal use ( they do take about 5 miles to warm up ) otherwise lots of water will collect in the exhausts etc. Just have a quick look at the choke cables where they are fixed to the carburettors and see if they fully open when selected ( water can freeze in the cables etc ) as if they were working correctly then they don't usually just fail.

Correct spark plugs or maybe coil cracked ?

I just think it is this severe weather causing your problems

 

[Mike the Bike]

I just think it is this severe weather causing your problems

I wish it were, but it really shouldn't need so much spinning on the starter, and huge clouds of smoke. I've had the bike a couple of Winters, so I'm used to what it should do (although this is about the coldest !). I'll check the timing, and maybe then have a look at the choke mechanisms. Nothing is sticking, everything springs and returns as it should.

Many thanks

 

[(RIP) Proff]

I wish it were, but it really shouldn't need so much spinning on the starter, and huge clouds of smoke. I've had the bike a couple of Winters, so I'm used to what it should do (although this is about the coldest !). I'll check the timing, and maybe then have a look at the choke mechanisms. Nothing is sticking, everything springs and returns as it should.

Many thanks

the choke assembly gasket and diaphragm

 

[electric_monk]

I was having the same problem with my 100Para after getting the carbs rebuilt. Finally on the way home from work it went completely off one cylinder and when I checked the coils I found that one of the HT leads was corroded really badly. I replaced the leads and cleaned the coil and now it starts first push of the button, even after I have had to use warm water to de-ice the choke, throttle cables and starter button. The white smoke is still there but it is not a concern

 

[DrFarkoff]

You were havin probs before ya rebuilt the carbs Silly!

I was having the same problem with my 100Para after getting the carbs rebuilt. Finally on the way home from work it went completely off one cylinder and when I checked the coils I found that one of the HT leads was corroded really badly. I replaced the leads and cleaned the coil and now it starts first push of the button, even after I have had to use warm water to de-ice the choke, throttle cables and starter button. The white smoke is still there but it is not a concern

 

[Mike the Bike]

the choke assembly gasket and diaphragm

Proff : I will check the chokes It will be the chokes. tonight I will remove the carbs, and check the chokes. The chokes it is (to be sure !) I will let you all know if the problem disappears, but in the meantime :

I will check the chokes It will be the chokes. tonight I will remove the carbs, and check the chokes.

 

[SJRoome]

Hi

+1 on check the chokes. Although you only really need to check the one that does not start.

The white/grey smoke could be oil burning. It could be coming through the valve guides or past the rings. If it is really bad I would suspect something was put together incorrectly during your top end re-build.

What does the smoke smell like? If you turn the engine over a few times on full choke and then pull the spark plugs what do they look like?

Steve

 

[Mike the Bike]

It smells vaguely of oil burning

When I re-assembled the barrels and head, I felt a little uneasy about those little rubber seals that fit between the barrels and the engine. I wasn't totally convinced they sealed properly. What symptons would it give, if that were the cause ?

 

[cookie]

oil mist around the join.

 

[fayeslane]

What was done on your top end rebuild? It may be something simple like having all the rings gaps lined up therefore potentially reducing compression as well as letting oil through. Were the valve guides done?

 

[Mike the Bike]

Both heads were fully reconditioned. I tried to ensure the ring gaps were not lined up, but I may end up checking again. Too cold tonight to venture into the garage. I'll have a look at the weekend .... thanks for all the guidance

 

[Steptoe]

You know what i'm going to say don't you Same as the post last year on the cold start problem....

Pour a kettle of boiling water over the carbs - and then see if it starts OK.

None of you old hands sussed out what the remedy is yet ?? I do like a good "who dunnit"

 

[(RIP) maverick]

You know what i'm going to say don't you Same as the post last year on the cold start problem....

Pour a kettle of boiling water over the carbs - and then see if it starts OK.

None of you old hands sussed out what the remedy is yet ?? I do like a good "who dunnit"

Nope as I have exactly the same starting problem as above without the plumes of white smoke on my R100T Will try the warm water thing tomorrow morning as the bike turns over for a while before running on one cylinder and then on both

All I can think is fuel doesn't vaporise well in cold carbs, and a cold battery has less cranking power. The combination often means lots of frustrating cranking, and often flooding the carby, and flattening the battery.

Pouring hot water over it will help to vaporise the fuel for a near instant start? Not sure how or what part this will relate to in the bing carbs though.

 

[Mike the Bike]

Ok - I tried the simple fix of pouring boiling water over the carbs. Anyway, IT WORKED !

So what do I need to fix now ?

 

[Mike the Bike]

pleeeeease Steptoe ?

I'll pay my subscription - about time really

 

[(RIP) maverick]

pleeeeease Steptoe ?

I'll pay my subscription - about time really

Ahh but only if it was that simple please check thread

http://www.ukgser.com/forums/showthread.php?t=220418

We are all wondering about this for a long time.