del_boy
Member
- Location
- Herefordshire
What did you do fix that?
Ive been driving it around with the choke out thinking it might get to go but no luck,
Small engine help
- Thread starter snipe
- Start date
Ive been driving it around with the choke out thinking it might get to go but no luck,
Mursal
Member
Exhaust off and burn out with a wee drop of kerosene outside with an extinguisher handy. Try without to test?
With a bit of a rev on the engine block the intake between air box and carburetor, (hand over the intake) might just dislodge a restriction in a jet. Also check for air getting in between carb and engine, bit of WD40 in a spray can see if it picks up.
With a bit of a rev on the engine block the intake between air box and carburetor, (hand over the intake) might just dislodge a restriction in a jet. Also check for air getting in between carb and engine, bit of WD40 in a spray can see if it picks up.
Mursal
Member
The original Honda problem:
Might be worth checking valve clearance if you have plenty of fuel and a spark?
Also worth throwing a bit (a cap full) of fuel into the carburetor (outside not in the shed) inlet, see if it runs different as it will have plenty of fuel? Again check for air leaks between carb and engine. Cylinder heads sometimes comes loose for no apparent reason?
Might be worth checking valve clearance if you have plenty of fuel and a spark?
Also worth throwing a bit (a cap full) of fuel into the carburetor (outside not in the shed) inlet, see if it runs different as it will have plenty of fuel? Again check for air leaks between carb and engine. Cylinder heads sometimes comes loose for no apparent reason?
- Location
- Matlock,Derbyshire
As Mursal says,just pop silencer off and fire it up for a quick check
wasted years
Member
- Location
- Cumbrian born and bread
I've been through all of this with my sons REV 3 125, the silencer has a replaceable 'wad' of material in it that do get full of oil, cheap and easy to replace just take the silencer apart and its there, you could always take the 'wad' out and try to run it with the silencer off and see if it helps.
There is loads of help online for the Beta carbs as they are notoriously difficult to set up and are temperamental but as others have said you will need to remove the carb, strip it and clean it, they are very easy to work on but need a bit of technique to remove in the first place.
wasted years
Member
- Location
- Cumbrian born and bread
No,
I would presume the 'wad' is fireproof so maybe it is a spark arrestor as well.
the 'wad' is like a rolled up old shirt and I always assumed was to silence the noise?
I would presume the 'wad' is fireproof so maybe it is a spark arrestor as well.
snipe
Member
- Location
- west yorkshire
Now and a gain when starting due to turning it over a while it back fires and get a little flame from exhaust. Will take it off tomorrow... Granddad been having a look under rocker cover today, he said on the combustion stoke just before TDC the exhaust valve is presses but only very slightly, dose that sound right?
Mursal
Member
Are you lads turning it in the correct direction @snipe?
Exhaust valve will open at the bottom of the power stroke and stay open all through the exhaust stroke (piston coming up). At the top of the exhaust stroke the inlet valve will be open as well (so both valves will be open a bit, also known as valve overlap). Then exhaust valve closes and the inlet valve stays open until the piston is coming well up the compression stroke. Inlet closes and the piston continues up until Top Dead Centre (TDC) with both valves closed. Where you get a spark and the piston goes down on the power stroke. And it all happens again.
Hope this helps a bit ...........
Exhaust valve will open at the bottom of the power stroke and stay open all through the exhaust stroke (piston coming up). At the top of the exhaust stroke the inlet valve will be open as well (so both valves will be open a bit, also known as valve overlap). Then exhaust valve closes and the inlet valve stays open until the piston is coming well up the compression stroke. Inlet closes and the piston continues up until Top Dead Centre (TDC) with both valves closed. Where you get a spark and the piston goes down on the power stroke. And it all happens again.
Hope this helps a bit ...........
snipe
Member
- Location
- west yorkshire
Will find out tomorrow.
Mursal
Member
Yes, just crank it on the starter / kick start / pull cord for correct direction.
Unlikely for timing to slip, but you never know ...............
With the piston at the top (TDC) and both valves closed have you clearance in the tappets?
About 0.3mm is the average clearance .........
Also worth checking tomorrow if not already checked?
Unlikely for timing to slip, but you never know ...............
With the piston at the top (TDC) and both valves closed have you clearance in the tappets?
About 0.3mm is the average clearance .........
Also worth checking tomorrow if not already checked?
Last edited:
snipe
Member
- Location
- west yorkshire
Which ever way the engine is going. It sounds like the exhaust valve is opening once full and a fraction a second time.. I’ll check for my self tomorrow
Mursal
Member
Oh, wait a minute would it have an auto decompressor fitted?
It may well have ...............
I'll have to try and find out more for you, it helps pull starting the engine, but as soon as it starts it automatically closes the exhaust valve. Honda quad engines definitely have it fitted. If it has one fitted, you can rule out the second opening of the exhaust valve as the problem.
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It may well have ...............
I'll have to try and find out more for you, it helps pull starting the engine, but as soon as it starts it automatically closes the exhaust valve. Honda quad engines definitely have it fitted. If it has one fitted, you can rule out the second opening of the exhaust valve as the problem.
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