carb problem?

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Was the throttle wide open while doing the compression test, and did you have a srtong battery to turn the motor over and all the plugs out? These numbers are very low.
 
:bang head:eek:h dear
you know what is like
new toy ,bloke,
test it ,check this thread
read whats been posted
read the instructions to the compression tester
re test the correct way
come up with 150psi to 155psi across the pots
sounds alot better
 
The problem now is that you've ruled out a bad piston/valves

Would a worn valve seat keep compression but allow a lick of flame back up the intake manifold?
Can you do a leak down test with your new toy?
 
man thinking about this problem a lot
if compression is ok......please tell me its not a crack in the head between
the valve chambers
not been able to find sombody with a leak down set up yet....!:ummm:
 
Having similar problem, just started looking at it last night.

I am going to my shop today to work on the bike. I just bought this yesterday and rode it 6 miles from my shop to the house.

I hauled it 6 hours and was dying to ride it when I got to my shop.

I ll post some pictures. But a mouse made a home in the air filter and clogged up the air filter.

All the carbs look good and like new. Just the rear lh slider isn't working.

Took out hte diaphragm and checked it and it seems ok. I don't see any rips etc. The metal insert was apart when I pulled it apart last night. So I epoxied it and its all good now.

Now I have to wait before I wake up the neighbors to see if its works. But with a finger push test, it seems to sound like its leaking air.

I ll post more as I find today hopefully.

Good luck
Todd
 
:ummm:ive just compleated the leak down test
found t,d,c, on compression stroke connected the tester and well check out the photoleakdown test.jpg
 
looks good to me
so what is there left to try
list of done things so far
changed the carb
changed the coil
compression test
leak down test
cleaned carbs
changed spark plugs
the red mist is starting to form........any ideas ?
 
Cam timing? Could the cam chain skip a tooth if it was loose (cam tensioner not taking up the slack)

Never heard of it happening to a Max though
 
well went down the workshop this morning removed the carbs
removed the rockerbox cover above the faulty cylinder
found small pieces of metal in the oil cathchers on the intake side
these look like parts of a valve spring
any thoughts or ideas would be greatfully received
unable to see which valve spring may be broken due to the fact
that the valve and springs are in a recess
cheers Rick
 
If you've got metal in there it's most prolly a great idea to take at least the rocker covers off for a good inspection. Refer to my 'how to adjust your valves' thread with pics to see what needs to come off to get there.
 
Back
Top