Symptons of blown o ring ADA head ? ?

[shepster]

Hi im having a few issues, hard starting once stopped after use, crappy midrange etc
Could this be caused by bad o rings ? Compression is ok 200psi in each :biggthumpup:

Thanks in advance

 

[Matt_E]

I've had it happen once to me on a Riva head. Unfortunately, it happened in Oregon surf that was about 12 ft .... no fun. Getting towed by an Ultra 250X is also no fun.

It ran on one cylinder only. Constant water spray into one jug killed combustion. I suppose a smaller leak might let it run, but not at optimum performance.
That head is easy to pull, why not have a look?

 

[shepster]

Yea thats tomorrows job, just flushed it out and fogged her up.But i did notice some oil residue around the plug o ring, as you say its an easy job. Why do things always happen when there running so good !

James

 

[SJBrit]

When my o-rings went bad I was running very lean. Unfortunately I was tuning the carb (well, Tricky was) and we ended up with some monster mains in there until we figured out that something was amiss!

 

[Big Kahuna]

could also be a sheared Flywheel Key, off just enough to make it run crappy.... would definately make it hard to start.

 

[shepster]

Dont scare me dude, its all new:bigeyes:

 

[matejzivic]

When my o-rings went bad I was running very lean. Unfortunately I was tuning the carb (well, Tricky was) and we ended up with some monster mains in there until we figured out that something was amiss!

I have problem that ony one cilinder is running dryer than other one. No screw or from 80 to 87.5 bigger jet doesn't change the situation. Could this be wrong?

 

[DAG]

if the compression is good, i doubt this a 0ring

 

[SJBrit]

I have problem that ony one cilinder is running dryer than other one. No screw or from 80 to 87.5 bigger jet doesn't change the situation. Could this be wrong?

Sounds like it. It's a quick thing to check, so just pull the head off and take a look. It doesn't take much of a leak at all to cause a problem.

 

[kid4now]

The proper way is to take the head off and check it. Other ways to start the diagnosis are:

1. ride it in the water at a little over idle and look at the pissers. If its shooting intermitant air and water you probably have a blown oring. It should be a solid stream of water.
2. run it and shut it down and look at the pisser if you have a good amount of hiss and steam come out it a good chance you have a blown oring.

Those are just 2 ways I start the diagnosis.

 

[shepster]

OK guys, keyway is good, stator is still at desired point, reeds are good, compression and o rings are good, carb and fuel system clean ! ! Any ideas ?
Start testing electrics i guess, argh !