Major engine repair

[CD]

There will always be a little oil in the airbox as it gets carried over by the breather pipes.

A little oil will not cause the carbs to choke. However if a choke valve is sticking or has a damaged rubber seat the affected carb will run like its on cold start. You need a good fitting open end 14mm spanner to remove the choke plungers.

If you are really sure its the breathers, route them into a catch bottle and see if the carbs improve. I suspect they wont. Its most likely dirt faulty chokes or wrong low speed air settings.

By the way, the throttle position sensor can also have an effect. There are posts on how to adjust that

[bo6o]

OK, so the problem is found - today I left the bike at my carb man, and before that in the morning I read about the heating of the carbs, and having in mind that the problem appears only when it's hot - I mentioned that this might be the problem - and after cleaning and synchronizing the carbs, my mechanic found out, that the heater's solenoid is not closing after reaching 35 degrees C.

Few questions - what will be the possible problems if we just disconnect electrically the heater's solenoid(valve or whatever) - the weather is a bit colder now?? Will it stay closed? Is it possible to find and replace the temp sensor or solenoid - wherever the problem is and what it will cost(if I order it somewhere on the net, cause I don't think I can find it here).

At last the problem is found, now I need the solution...

[bo6o]

And the story continues - the temp sensor on 4th carb was not working, so my mechanic cut it off(until I find another one) and so no oil is heating the carbs. When I took it from him - it was working like never before - silent, strong, and the slightest touch of the throttle made it fly.
Filled the tank and went testing. After driving about 20-30km - everything was back as before - the bike was working only above 4000rpm and below 2000(quite unstable in the low rev). So again we are at the beginning, with no answers.
The only thing I could think of is the tank breather - I opened the cap and blew through the vent hose - I think it's clogged, but when I was opening the cap, there was no sign of vacuum or whatever air movement. When I rev in neutral - it revs perfectly. I put it on gear and start off - it dies. HELP people, or I'm buying a shotgun and will become a divi killer....

[Sean]

If it is the breather from the engine to the airbox then clean it and ALL other connecting hoses out, take the airbox off and dismantle it, and clean it out in the inner chambers not just where the air filter fits - it might be full of white gunge blocking the air intake hence the bike struggling - check all hoses are clear.

Maybe it seems that the solid hosepipe replacement is required - as per the above tips.

Don't lose heart and give up as these things once fixed are soon forgotten.

My D9 was coughing and spluttering on one occasion and I was thinking of replacement carbs? New jets? Top end rebuild?

Turned out it was a plug going down when hot - check your plugs maybe too?

[bo6o]

All the breather hoses are clean. I suspect only the fuel tank one. What do you mean by plug?

[bo6o]

Sept 8, 2011 15:02:15 GMT bo6o said:

And the story continues - the temp sensor on 4th carb was not working, so my mechanic cut it off(until I find another one) and so no oil is heating the carbs. When I took it from him - it was working like never before - silent, strong, and the slightest touch of the throttle made it fly.
Filled the tank and went testing. After driving about 20-30km - everything was back as before - the bike was working only above 4000rpm and below 2000(quite unstable in the low rev). So again we are at the beginning, with no answers.
The only thing I could think of is the tank breather - I opened the cap and blew through the vent hose - I think it's clogged, but when I was opening the cap, there was no sign of vacuum or whatever air movement. When I rev in neutral - it revs perfectly. I put it on gear and start off - it dies. HELP people, or I'm buying a shotgun and will become a divi killer....

So again on the road to death...

All the breather hoses were inspected. The spaks also. The carburetors were checked again and they are adjusted and compared to the carbs of exactly the same bike, from the same year(even the color was the same) - the other bike has no problems.
The air filter is new, the air filter box - inspected. The carburetor temperature sensor is cut off, because it was heating the carbs non stop, and it's 30 degrees Celsius here. The oil is 15W50 Castrol - new, with new oil filter. My mechanic lowered the fuel level as much as possible...
AND NO!!!
When the engine gets warm, in the dry hot weather - the bike works only under 3k rpm and above 4k. Above 4k - works uneven and doubtful a little bit.
I ran off ideas of what can be wrong. Has the time for opening the engine come. Should I sell it to another fool like me. Or should I pour some petrol on it and burn it down for all the white hairs on my head.

Please people, give me some advice. The bike likes it only when it's cold, and I don't

[neilmud Lord Protector]

May not be mutch help but years ago I had a Vauxhall van that did somethind simmilar it turned outy to be the ignition coil.

Neil

[bo6o]

I totally f*cked up the bike



I wanted to recheck the temp sensor, and I over-screwed and it cut off and the head has left in the hole. The worse thing is that in this way it is not sealed and fuel is leaking from there.
So, until I find a replacement for that part, is it possible to fill the hole with some sort silicone or something like that temporary. I don't think it's possible to remove the part that's left in the hole, so I'll need a new floatchamber cover I guess, and specially the one with the temp sensor.

Here's the place to ask - does anyone know where can I order one and does anyone of you sell such?

[bo6o]

Hello from me again.
You may tag the thread as SOLVED, as I collected my bike a few days ago from another mechanic. The problem was in the so called emulsion pipes, where a needle or a jet(don't know it in English) lies - I was told this is a common problem in some bikes, as these pipes lie horizontally and they wear out. So the problem was cured by proper adjusting of the fuel, so the bike doesn't choke between 3-4k when hot.
If someone understands my explanation, he can try to explain it more accurate.
Some valves needed adjustment-done.
As I expect the problem to appear again, does anyone know where I can find and order all the needles and jets, the mentioned pipe and all the little parts in the carbs, that tend to wear out, so I can really repair the bike?

[amorti]

I think I understand.

About 3-4k is just where the slides start to lift. So it could be that between vibration and general wear, your needles have got a "step" wear in them, this would mean that right as the needles lift, there is too much fuel going in (choke) but this would resolve as the needles lift above the wear mark. So this would perfectly explain why there is a small step in the rev range where the bike runs too rich, and too rich means it will choke especially when warm.

It is worth considering the tiny tolerances carbs operate to. The main jet, ie when the carb is fully WOT, has a hole for fuel around 1.1mm in diameter (can't remember the exact size but it'll be ITRO a 110 jet?) so if there is any wear at all evident then at lower revs where the needle restricts the fuel flow, this will become very apparent.

Glad he has soled the problem for you. Sounds like, if it's really worn in this way, you would be better off with a newer set of carbs, or with new emulsion tubes and needles.

If you start getting problems due to cold weather, add about 170 - 250ml of IPA to each tank of fuel, that will solve it completely.

www.ebay.co.uk/itm/IPA-ISOPROPYL-ALCOHOL-ISOPROPANOL-1-LITRE-min-99-pure-/220465604731?pt=UK_BOI_Medical_Lab_Equipment_Lab_Supplies_ET&hash=item3354c6287b

[bo6o]

Cold weather is my best friend - this is when the bike runs really nice, but my body doesn't like it
Today it was 2 degrees Celsius when I went to work, and when I arrived - there was frost on my helmet and it took 2 hours to start feeling my fingers again(summer gloves with winter pads).
Is it strange that I don't have problems in cold and damp weather, as my carb heating is turned off?
Also, today I rode with my girlfriend for the first time, and there was a really noticeable decrease of power-is this normal?

And I looked for newer carbs, but none were even near to newer on ebay - Germany and UK.

[amorti]

Yup, you will definitely notice the difference 2-up. The brakes will be noticeably weaker, too.