Stihl BR 800x valve click

[ruSSrt]

Hey guys.



I have never seen this before. I don't think it's not normal. What could be the problem here? Why is it doing that. It was running very well up until yesterday and slowly quit. But sounded like carb issue so I was cleaning the carb. And since it was apart already I was going to check valve clearance and came across that.

 

[Brian123]

Here is my 1st question, what 2 stroke oil have you been using in this Blower?

 

[mk378]

The valve on the right is sticking in its sleeve then snapping back up when it breaks loose. You can probably get the same effect pressing it down by hand instead of turning the crank. This is a build up of gummy residue on the valve stem. It will of course prevent the engine from running since there's no compression.

 

[ruSSrt]

Here is my 1st question, what 2 stroke oil have you been using in this Blower?

I've been using Opti-2 lube at 50:1. Although that lube is advertised as 100:1.

 

[ruSSrt]

The valve on the right is sticking in its sleeve then snapping back up when it breaks loose. You can probably get the same effect pressing it down by hand instead of turning the crank. This is a build up of gummy residue on the valve stem. It will of course prevent the engine from running since there's no compression.

Thank you. I've never seen sticking valve before and this one is first. Time to clean valve seats.

 

[Brian123]

I've been using Opti-2 lube at 50:1. Although that lube is advertised as 100:1.

Am I correct in that this is a fairly new Backpack Blower, how long have you had it? I do realize its probably hard to determine how many hours you have used this Blower.

 

[ruSSrt]

Am I correct in that this is a fairly new Backpack Blower, how long have you had it? I do realize its probably hard to determine how many hours you have used this Blower.

I purchased it used about a year after they came out and have been using it mildly since then. I had some left over Opti-2 Lube (blue stuff older) that i mixed at about 1:50 and then splash of MMO. Never had any problems with any of my equipment running that.

 

[ruSSrt]

The valve on the right is sticking in its sleeve then snapping back up when it breaks loose. You can probably get the same effect pressing it down by hand instead of turning the crank. This is a build up of gummy residue on the valve stem. It will of course prevent the engine from running since there's no compression.

So I tried pressing down on it manually to see if it do the same and can not reproduce it. Also I'm thinking about soaking it in carb cleaner/break cleaner to possibly loose some of that build up while it is still put together. If it wont work i'll have to take the whole thing apart

 

[ruSSrt]

okay guys..... check this video out. Link starts at 3:45 watch for this guy rotating the pistol and he gets the same click. He does it twice and same drop/click on exhaust side. So is that suppose to be like that?



Also, this is brand new machine. They showing how to do adjustment on the valves and same click.



I'm 100% confident now that it is not sticking valve.

 

[mk378]

It may be supposed to do that. There is some sort of compression release on the 4mix engines.

 

[Brian123]

I purchased it used about a year after they came out and have been using it mildly since then. I had some left over Opti-2 Lube (blue stuff older) that i mixed at about 1:50 and then splash of MMO. Never had any problems with any of my equipment running that.

So you purchased this piece of equipment used, realistically we do not know how this Blower was used before you got it, meaning what 2 stroke oil was used and at what ratio.

 

[jeepman3071]

It may be supposed to do that. There is some sort of compression release on the 4mix engines.

This is my thought, a compression release. I've seen something like this on other engines. In my opinion it would be strange for a valve to stick that consistently.

 

[ruSSrt]

So you purchased this piece of equipment used, realistically we do not know how this Blower was used before you got it, meaning what 2 stroke oil was used and at what ratio.

Yes. Totally agreed with you. usually my go-to when i purchase used is check compression, poor man method and look in to exhaust to see if there is carbon build up. if its too clean than possible damage, if its too gummy too much or bad oil been used.
after i get it home i do quick maintenance. Filter, spark plug, fuel filter and look down the piston. If its too gummy i'll soak it in some nasty solution and then run it out.