dek 11hp engine question

[jetrail]

Has anyone ever worked on a dek motor ? . I have a 11 hp dek motor on a brush master chipper shredder model ch3 . The owner said he used it twice and after that when trying to start it you can only pull the cord out till it builds up so much compression you cant pull it anymore. When you remove yhe spark plug it pulls fine . Ive checked the flywheel key , valve clearance ect . Im stumped , could it be the cam binding?
Thanks

 

[Lawnranger]

What was the result of the compression test you performed?

 

[jetrail]

Well it only will pull about half way and just from that it was hitting near 70-75 lbs of pressure .

 

[Lawnranger]

If I understand you correctly, you are not able to complete a full crankshaft revolution when pulling on the starter cord, is that correct?

Recently I have had two generator engines, one a Briggs and the other a chinese honda clone that both had the same symptom and the same cause. The symptom was that the engine would turn about 350 degrees one way and the same amount the other way. The cause turned out to be a brown, powdery substance on top of the piston coming in contact with the combustion chamber in the cylinder head. The technical term is CCDI or combustion chamber deposit interference. This substance was not the familiar black carbon but rather a brown powdery substance. I cleaned out the deposit and both engines operated as designed. Perhaps this is the problem you are experiencing?

 

[Lawnranger]

Wrong spark plug? Too long?

 

[jetrail]

The thing is brand new so i dont think its the wrong plug but i will check to confirm . Its a ohv engine and yes you are right you cant pull it through a full cycle . It tightens up right about half way . I marked on the starter cord where it tightens up or builds up so much compression and i pulled it again and let it recoil back to where i marked and it was tight right at that spot . Ive tried different starter tops ect so it has me puzzled .

 

[jetrail]

Also could this thing have ccdi after only been ran two times?

 

[Lawnranger]

Also could this thing have ccdi after only been ran two times?

If some foreign matter got in the cylinder it could.

 

[Lawnranger]

The thing is brand new so i dont think its the wrong plug but i will check to confirm . Its a ohv engine and yes you are right you cant pull it through a full cycle . It tightens up right about half way . I marked on the starter cord where it tightens up or builds up so much compression and i pulled it again and let it recoil back to where i marked and it was tight right at that spot . Ive tried different starter tops ect so it has me puzzled .

The next step I would take is to remove the recoil starter and turn the engine over by hand to determine if the problem is with the starter mechanism or the engine itself.

 

[jetrail]

I had it off when i pulled the flywheel . You can turn it by hand but turning it that way is so slow compaired to pulling the rope . It seemed like it turned a little easier . But when i put a different dek top on it it still binds up . Maybe its the cup because when o took the top off i pulled the top and it pulls fine . It also pulls fine without the spark plug so i def think its compression related