I dont understand?? can you help?

[lam1962brettagg]

Recently had an rt195 + 30mm phbh + 42mm exhaust fitted.
no problems to begin with, running a bit rich so sealed exhaust downpipe and box.
done 200 + miles running in.
lost tickover when last out, and started to run ruff.
investigated, cleaned carb, adjusted throttle cable.
tried to adjust tickover screw after adjusting air/fuel mix and no reaction at all from the idle screw??
choke ok, can see the choke closing through aparture on carb.
so basically running badly, and cant adust tickover using the idle screw (front of carb)
anyone had a similar problem or know whats happening?
cheers

[MickYork]

The tickover screw usually opens the slide, not by much but enough to alter air flow. The tickover screw has a sharp, needle like, end which wears down over time, causing the screw to miss the slide and not make any difference when it's screwed in or out. This may, or may not, be the case.

Have you plugged chopped it at 1/8, 1/4, 1/2 and full throttle settings ? might worth doing.

[lam1962brettagg]

Hi Mick
understand your first, seems to be moving slide up and down when I look at it, and screw in or out, but when running its not altering tickover at all.
sorry your last sentence was over my head?
cheers anyway

[MickYork]

What is your carb set up ....jets, needle, slide, etc

It's possible your pilot is too big ?

[lam1962brettagg]

not sure but I'll let you know.
all running fine for first200 miles, started first kick etc.

[MickYork]

In theory.... when you was running rich and had a small air leak (exhaust) by making good the air leak you richend it up even more.

The plug chops as mentioned, are to check your air/petrol ratio at different stages. Initially your carb is only running on the pilot jet, then as rev's increase (throttle position) you gradually move on to other factors (slide, needle, atomiser) before, at roughly 3/4 throttle, your main jet comes into play. It's important to have the correct set up in all these positions.

[lam1962brettagg]

Thanks Mick
and thanks for putting in laymans terms.
I get it now.
but still dont understand why I lost tickover while out on the road b4 I sealed exhaust properly.
I did notice though a sudden huge jump in fuel usage (jetting I guess)

cheers

[coaster]

Is there any possibility you have had a mild nip up and are down on compression

[lam1962brettagg]

Hi if I did, I Didn't notice anything.

[coaster]

Hi if I did, I Didn't notice anything.

If the loss of idle came on suddenly then its unlikely to adjustment, more likely something has changed as in faulty. You dont say if you have checked the obvious, the spark plug would be a good place to start, these fail quite often especially if run rich (NGK are notorious for knock off copies)

Reeds would also be worth checking

[lam1962brettagg]

Hi coaster
thanks for input,
I've put two new plugs in both halfords, I'll try another but fail to see how this could have an effect on the idle screw though.
but then again I certainly no expert on kits.
as for reeds, not sure If I have them. dont think I have.
cheers

[Meds]

Do you have an air filter that could be blocking up?
The needle clip has fallen off and the needle is moving around freely.
Check the carb rubber for splits?

[lam1962brettagg]

Hi thanks
bgm mesh type air filter (original air box type)brand new
will check float needle and carb rubbers but should be ok as they are new.
cheers

[MickYork]

Try running with no filter...….does this make any difference ?

[Rich Oswald]

If you think about it, if it was running ok and ticking over ok and then it wasn't suddenly, then something has changed and no amount of changing jets or filters or whatever is going to rectify it. Something has gone wrong like you have an air leak, a blockage, a sticking choke cable etc, etc. Find the cause and then you can put it right.
By the way an RT 195 kit with 30MM PHBH will need a better revving exhaust than a 42mm Clubman to get the best from the kit. Just my opinion of course.

Rich'

[lam1962brettagg]

Hi Rich
thanks for input.
All ran fine for 20 mile run, came to a stop and lost tickover, engine stopped.
kicked over and got home. problem seemed to get worse while trying to find the fault and adjusting idle screw and throttle cable.
have not been out on it since, runs very badly in the garage, wont tickover, wont start occasionally splutters and stalls.
have canged plug twice, checked fuel, checked for airleaks, choke checked,
cleaned and blown through carb and jets with airline. ran it without air filter no change worse if anything.
stumped.

[lam1962brettagg]

Do you have an air filter that could be blocking up?
The needle clip has fallen off and the needle is moving around freely.
Check the carb rubber for splits?

all checked thanks all ok.

[MickYork]

Might be worth checking fuel flow rate from tank

[lam1962brettagg]

Might be worth checking fuel flow rate from tank

Might be worth checking fuel flow rate from tank

Might be worth checking fuel flow rate from tank

all checked and ok Mick
cheers

[MickYork]

breather hole in petrol cap ?