How about using the old regulator as a test .Can it be used with other electrical there
I had one go bad. Hot Causing ignition problems
I had one go bad. Hot Causing ignition problems
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low compression?
- Thread starter cashonly
- Start date
the rectifier went bad the regulator was still good but i wasnt sure how to repair the rectifier so i got the solid state one
This is a heat dependent problem that has started after some work have been done
I would try to contact the seller maybe he have something to say. Sometimes they help out
Making own separate regulator and rectifier off car parts can be found on forum
A rectifier only perhaps using the old regulator for test
I would try to contact the seller maybe he have something to say. Sometimes they help out
Making own separate regulator and rectifier off car parts can be found on forum
A rectifier only perhaps using the old regulator for test
Capacitors (and caps) do go bad. Try a new one
While on the low side of acceptable those readings are consistent enough for government work.
Used to fly piston planes and the compressions at each annual would move around like what you show.
I've got an XS650 I've done lots of compression tests on over the years and they move around a bit also.
Idle screw to seat, pilot jet, and the float bowl orifice are all tiny doesn't take much to restrict them. Drain your float bowls into a clean container, any debris?
You bike is a 360 degree parallel twin, the crankcase is like a giant air compresser, it's normal for a LOT of air to come out if you open the cap while running. Word to the wise; NEVER start an XS with a valve cover off......
While on the low side of acceptable those readings are consistent enough for government work.
Used to fly piston planes and the compressions at each annual would move around like what you show.
I've got an XS650 I've done lots of compression tests on over the years and they move around a bit also.
Idle screw to seat, pilot jet, and the float bowl orifice are all tiny doesn't take much to restrict them. Drain your float bowls into a clean container, any debris?
You bike is a 360 degree parallel twin, the crankcase is like a giant air compresser, it's normal for a LOT of air to come out if you open the cap while running. Word to the wise; NEVER start an XS with a valve cover off......
JJames
XS650 Addict
Gary makes some good points. I wouldn't worry too much about the compression numbers or inconsistency. And you will always have a good amount of air pressure in the crankcase when running. I would consider the automotive reg/rec swap that Jan mentioned. But mostly it's common for tiny debris to stick in small holes and passages of the idle circuit. This will result in the"choke only" situation you describe. I would triple check this area and while you're at it possibly up a size or two on pilot/main to better suit your exaust/air box or lack thereof. Nice bike. Have fun and keep us up to date.
i checked vlave clearances and triple checked all carb passages , nothing wrong with either , im gonna research a possible way to check the new solid state reg/rec that i just bought and rule that out but at present i bave a new top end gasket kit, new piston rings, and an engine stand on my work bench ready to pull the motor and do a top end refresh on it to hopefully get some compression back and fix the oil leak
is it normal for changes in the ignition system to warrant changes in jets ?
thanks for all the compliments in my bike , sure do love it and i wish it ran !
Just disconnect it. it can't cause problems if it's disconnected.
Charge the battery, disconnect the reg/rec and see if it runs OK.
Highly... highly unlikely a reg/rec could cause problems in a points motor, but you can run without it and find out.
its stock charging system
maybe im being thick but i feel like since the problem is only when the engine is warm , and only without the choke on it is unlikely to be an ignition issue ?
my battery is charging fine and my plugs fire on time and orderly
and if you employ the process of elimination that i learned here
if problem arises
1st check spark if spark is good
2nd check compression if compression is good
3rd check carb
i stopped at compression because its lower than reccomended spec and and the valves are within spec thats how i ended up with this gasket kit and piston rings on my workbench lol
my carbs have had the same jetting since i bought the bike aside from a main jet upgrade
they were brand new mikuni vm
34s and they have rarely ever been an issue
my plugs even looked really good upon inspection maybe a tad rich but carbs feel unlikely to be an issue as well
is there anything within the realm of low compression that would illicit a choke only idle ?(when warm)
before the bike warms up you can hop on it no choke as long as you dont let the throttle out all the way and get up the road fine but when the bike is at operating temp and choke is off , you give it throttle and it dies
It is not so simple ..A misfire has many variables
Mixture / Spark being the most important
A defect heat dependent Electrics fault can when hot short circuit to ground entirely or partly.
fex the reg /rect Combo
dropping the Voltage causing a weak spark. Or raise the voltage above spec
But a rich mixture can also give the same symptoms as weak spark
I dont believe carburetors give problems without other symptoms Unless dirty which you say is not the case
I dont believe it is the Compression.
Work has been performed and then the problems
In experimental solution finding it is there to start roll back or get new
Capacitor has been mentioned
A new regulator or rectifier is not expensive
Mixture / Spark being the most important
A defect heat dependent Electrics fault can when hot short circuit to ground entirely or partly.
fex the reg /rect Combo
dropping the Voltage causing a weak spark. Or raise the voltage above spec
But a rich mixture can also give the same symptoms as weak spark
I dont believe carburetors give problems without other symptoms Unless dirty which you say is not the case
I dont believe it is the Compression.
Work has been performed and then the problems
In experimental solution finding it is there to start roll back or get new
Capacitor has been mentioned
A new regulator or rectifier is not expensive
