compression VS camshaft timing 2005 gtx wake 155

[Fvillar]

Hello to all and as allways thanks for your help and ideas to fix my problem

so here i go first a little story
bought this used gtx 110 hrs on it when i got it the first thing i noticed it was not doing more then 5000 rpm but the impeller was very bad and when cavitating it could go all the way to 6300 rpm
so new impeller and pum and wear ring all was new and again no more then 5000 rpm but no cavitation so step 1 done


i did all the things the manual said with no results even checked engine alignment electronical stuff also cheked with the computer so no error codes
BUT there is always a but isnt it
i checked the the engine compression and buum 150 psi on all 3 cilinders found the problem but (another one) i dont want to take the engine out to find out that there was another thing so before i take the engine out i had an idea the cam shaft timing might be off so i took the cover off and moved the timing it was almost fully retarded so as a test i set it to fully advanced and WOW 180 psi on each cilinder but guess what still no power max rpm 5300 and engine doesnt run nice when cold.

so before i take the engine out and spend alot of money on getting the parts and all to fully rebuild the engine do you think it is a good idea to set the timing as the manual says and look for more things or start moving the timing little by little to get the max power or what do you think i should do new timing chain??? or what i am a little frustrated to be honest

again thanks for your help and ideas

 

[Kris69]

In any 4 stroke engine, if the cam is advanced beyond standard it lowers the peak power rpm but it makes more from idle. This is why it won't make power at the top end. The more advanced it goes, the lower the top end is regardless of compression. Put it at standard and then try again.

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[Fvillar]

In any 4 stroke engine, if the cam is advanced beyond standard it lowers the peak power rpm but it makes more from idle. This is why it won't make power at the top end. The more advanced it goes, the lower the top end is regardless of compression. Put it at standard and then try again.

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ok i will thanks for the help just one thing what happend when the cam timing is fully retarded can i also experience the low power and low rpm and low compression ???

 

[Kris69]

Yes for sure. A retarded camshaft will take away bottom end power for sure and lower overall compression as you have found out and will never produce the power it's meant to.

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[Fvillar]

thanks alot i will get to work on the timming and let you know my findings

 

[AircraftDoc]

How did the timing move, is the real question. What caused this? Loose bolt, bad gears, or stretched timing chain. Anyone know if there was a gear bolt recall? I seem to remember reading it somewhere.

 

[Fvillar]

How did the timing move, is the real question. What caused this? Loose bolt, bad gears, or stretched timing chain. Anyone know if there was a gear bolt recall? I seem to remember reading it somewhere.

Hello
to answer your question i bought this PWC used and it looks like some one has allready set his hands on this engine about the recall it was on 2007 models if i remember well

 

[Fvillar]

OK so doing thing as the manual says I set the timing yes i did look the cam shaft here a pic of how it was look at the lines

next pic is how it ended

so here you an see the lines in good alignment with the head at the end I got 150 psi on each cilinder will have to test it and let you guys know what happend

Enviado desde mi SM-G900H mediante Tapatalk

 

[Kris69]

That looks better and 150psi seems better too.

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[Sea Dood]

The lines on the camshaft sprocket have nothing to do with cam timing, other than letting you know you are in the proper overall position for setting up the timing using the crank holding pin and the camshaft holding pin. Most of the time, when you have proper cam timing, the marks not level with the head. Once the cam and crank tools are locked, the timing is spot-on regardless of where the marks line up.

Just because you get more compression by either advancing or retarding the cam timing means nothing. As another poster said, advancing and retarding will only sacrifice either high end power or low end power. On a low horsepower engine like yours, it is best to set the timing via the tools and be done with it.