I'll turn to the forum and maybesomeone can give me some advice on how to resolve the problem
Keihin FCR MX 39 carburettor
I set the jets as per factory
Main air 200
Idle air jet 100
Starting Jet 85
Main Jet 178
Idling Jet 38
OBDVT pin clip at the 7th notchstarting from the top, the manual says 6 but it didn't start for meand I had to put it on 7
Mixture screw 1.5 turns
Valves adjusted with tolerance as permanual
New spark plug, strong spark, timingok, stator ok.
The sprayer is new
I overhauled the entire carburettorwith all new seals
To start it cold:
1. I pull the cold starter (black lever at the top);
2. I push theaccelerator 3 or 4 times so that the pickup pump sprays petrol;
3. With theelectric starter 3 shots and it starts;
4. I had to adjustthe idle screw almost completely closed;
5. I inserted aclosure under the air filter as present on the section of the pieceswhich limits the passage of air;
It needs to be greased a lot when itstarts but then doesn't keep the idle.
I'm afraid it might be a compression problem
From the test I did with the pressuregauge screwed in place of the spark plug it gives me a value ofaround 55-60 PSI, I don't know if it's correct or low.
Can anyone give me some help or sometips on what to check?
Could it be a problem with theautomatic decompressor or valves that aren't holding?
I wanted to try connecting the aircompressor and putting pressure on the head to understand if aircomes out of the carburettor or the exhaust. I don't know if it couldbe valid as a test.
Thank you.
Mark
Keihin FCR MX 39 carburettor
I set the jets as per factory
Main air 200
Idle air jet 100
Starting Jet 85
Main Jet 178
Idling Jet 38
OBDVT pin clip at the 7th notchstarting from the top, the manual says 6 but it didn't start for meand I had to put it on 7
Mixture screw 1.5 turns
Valves adjusted with tolerance as permanual
New spark plug, strong spark, timingok, stator ok.
The sprayer is new
I overhauled the entire carburettorwith all new seals
To start it cold:
1. I pull the cold starter (black lever at the top);
2. I push theaccelerator 3 or 4 times so that the pickup pump sprays petrol;
3. With theelectric starter 3 shots and it starts;
4. I had to adjustthe idle screw almost completely closed;
5. I inserted aclosure under the air filter as present on the section of the pieceswhich limits the passage of air;
- After it has been on for a while with the idle high, I close the starter lever when cold and the idle goes down but the motorbike turns off. If I give the gas it starts again well but as I cannot act further on the screw it goes off and I don't understand how to adjust it. the minimum and where am I doing it wrong or where is the problem;
- When it's hot, starting again without the cold starter, I always have to give 3 or 4 thrusts of the gas, it starts but doesn't idle and then switches off.
It needs to be greased a lot when itstarts but then doesn't keep the idle.
I'm afraid it might be a compression problem
From the test I did with the pressuregauge screwed in place of the spark plug it gives me a value ofaround 55-60 PSI, I don't know if it's correct or low.
Can anyone give me some help or sometips on what to check?
Could it be a problem with theautomatic decompressor or valves that aren't holding?
I wanted to try connecting the aircompressor and putting pressure on the head to understand if aircomes out of the carburettor or the exhaust. I don't know if it couldbe valid as a test.
Thank you.
Mark
