2002 f80 knocking

[Woodrow246]

Hey guys, Dad and were heading to fish on Thursday and about 25 min into the run my F80 started making a bad knocking sound. killed it, came in on the kicker. got it home and it wont turn over. Looking at tearing into it in the next few weeks to see WTF. It has ran flawless and been maintined very well. Took the valve covers apart and looks great, i can see the top of each piston they all look good, the move up and down as well so I am ruling out a broken rod. I am going to remove the power head but need some info if anyone has any on how it comes off. i am thinking I might have spun a Crank bearing or something similar. With the plugs out it is pretty tight when turning over with the flyweel and a ratchet. Any info on the teardown much appreciated!

 

[Bluefish]

Re: 2002 f80 knocking

Have you check the lower unit it can also cause what you are describing

 

[Woodrow246]

Re: 2002 f80 knocking

Bluefish I have not, I just assumed that in nuetrel i should get the motor to turn over and idle normal...is there something that would fail and cause this? I can get the prop to spin freely and the controls seem to work normal...however i am not farmiliar with how the lower end mates to the powerhead

 

[rodbolt]

Re: 2002 f80 knocking

if the gear case fails it can and will lock the powerhead.
remove it and retest the crank.
hope you did not pull the cam sprockets yet

 

[Woodrow246]

Re: 2002 f80 knocking

Rodbolt, i did remove the cam sprockets but just to get a look see at the valvetrain...I didnt move anything so i am ok with the timing...are you talking about just removing the lower unit? thx again

 

[rodbolt]

Re: 2002 f80 knocking

yes remove the gearcase.
however that is a non clearence motor. miss the cam timing by more than abot two cogs and turn the crank and you may get to post about bent valves
there is a procedure for pulling the sprockets where you line up the sproket marks and the TDC marks BEFORE removing the tensioner or sprokets.
goes for most any belt driven non clearence overhead cam engine.

 

[Woodrow246]

Re: 2002 f80 knocking

Thanks Rodbolt. I will remove the lower unit/ and verify the sprockets didnt move as I did pull the tentioner. I took a pic of the sprockets before i removed them and have that as a reference but didnt note the TDC mark. Any help on the procedure for this Much appreciated! i will keep you informed of my findings

 

[rodbolt]

Re: 2002 f80 knocking

if you have moved the crankshaft with the belt removed from the sprokets there is a good chance you damaged a valve and a very good chance you wont ever line up all the timing marks properly.
once open the pistons wont clear the valves.
so with the sprokets off a certain amount of intake and ex valves will be open,if you rotate the rank in this position pistons bend valves.
its that simple.
if you did not properly align the crank mark,and the sproket marks BEFORE removing the belt AND the crank has been moved with the belt off the ONLY way to get it back without valve train damage is to remove the cams, pay ATTENTION to the service manual as the cams are hollow and will break if the caps are not released correctly.
then line up the sproket mark under the flywhel assy to the mark on the block. then reinstall the cams with the intake cam sproket pin pin aft and the ex cam pin fwd that aligns both sproket arrows together.
best is to uy the factory F80 manual and follow the steps or take it in to a dealer that knows 4 strokes.
wont be the first set of bent valves I have changed due to the crank being rotated with the belt off or the sprockets not lined up correctly and the engine turned.

 

[mommicked]

Re: 2002 f80 knocking

Rodbolt.Whats an approximate bill for having the belt changed ?and valves adjusted on this motor by a certified yama. tech?

 

[Woodrow246]

Re: 2002 f80 knocking

I never moved the crank just pulled the sprockets, never moved the cams either. They are pointing at each other with the TDC arrow pointing at the arow on the bracket that holds the flywheel cover on...either way I pulled the Powerhead today and the oil pump has minute metal shavings in it so I am thinking lower end trouble/bearing job. I will remove the pan and hopefully split the lower end case tomorrow afternoon. i will be starting from scratch so I will need to do the timing procedure. the opposing TDC arrow on the opposite side of the flywheel(towards the front of the motor appears tp be -10 Deg off TDC with the other arrow on the fromt of the motor(little stainless bracket with an arrow on it) this is how it was before removal, I think it is pretty clear that with the cam sprocket arrows pointing at each other and the TDC mark towards the rear of the engine lined up with the arrow on the bracket, That this is correct. i will just need to make note of which two pistons are at the top of the stroke prior to removal....thanks for all the help guys. One other thing, I am assuming new crank and bearings(probably rod bearings as well) any thoughts of parts availability and/or pricing?

 

[rodbolt]

Re: 2002 f80 knocking

if your going into the motor anyway go ahead and remove the cams, note all the cam caps are numbered and the numbers are upside down and the ex side caps and cam are pink marked.
keep it ALL in order.
as soon as the cams come off,use carb cleaner to get the oil off the shims.
mark the intake side I1-I8, the EX side I simply number 1-8.
remove the caps and buckets together and place them in a secure container that wont tip over.
trust me if you scramble them its about a 6 hour operation to rearrange them.
you dont set the crank to cam timing with the flywheel, you use the plate under the belt drive gear and the casting tab on the block, just like the service manual shows.
pistons 1&4 will be at TDC when its correct.
methinks ya need a FACTORY F80 service manual , this aint a car engine and no undersize bearings are avalible.
the bearings are a select fit based on numbers stamped in the block and on the crank journal then you look up the color codes for the correct colored bearing sleeves.
if you follow all the procedures to reassemble the crank and the block you will have it apart about 4 times, always use new rod and main bearing bolts on the final assy.
you may find Jasper will sell you a reman cheaper than you can build it.
thats where ALL our blown warrenty powerheads go now.
if a crank journal or a rod big end or pin end is damaged its replaced. no grinding of cranks or replacing just a rod or a piston.
piston and rod are sold as an assy, crank is sold seperatly.
mommicked you know the hijack rules

 

[mommicked]

Re: 2002 f80 knocking

I opaligize to all.i thought my questoin might help the poster as well and that was ok.I wondered why I seem to be shuned, but have never had PM from a moderator correcting me yet.Ill try to respect/follow all the rules.thanks Rodbolt.

 

[rodbolt]

Re: 2002 f80 knocking

no worries, and I have answered a lot of your threads, start a new one and ill look for that one too.
I have an answer just dont want to get posts confused.

 

[mommicked]

Re: 2002 f80 knocking

I have just read the rules again and I believe I may or or maynot have violated the first 5!!more than once!I did not do it intentionally.and will try to not do it again.Ill also try not to PWD,post while drinking,anymore.i have a hard enough time sober!!

 

[rodbolt]

Re: 2002 f80 knocking

hahahahah
you aint the first to ever keyboard while drinking, and I am one up on ya, the mods have got me a few times .
could not balk though I was in the wrong.
but sometimes it gets confusing when the post topic keeps changing up then more and more folks change it and then I walk away.
I am easily confused to start with.
but fire up a thread on what it takes to change a belt and check valve lash on the F80,90,100 carb models and the F115.

 

[Woodrow246]

Re: 2002 f80 knocking

Looking into New powerhead just incase I go that route. Having a hard time finding an F80 one though...Heard the F75 is the same however. Is that the one I need? i know yamaha only made these for 3 yrs...any info much appreciated....The heads are fine so just a shortblock if there is such a thing.

 

[Woodrow246]

Re: 2002 f80 knocking

Hey all...once again with the input from everyone here, things have gone darn good! gotta quick one for you folks after endless searching without an answer I am looking for(not that there isn't good ones bun gunshy after the F80) Gota about 5 hrs on my f115(2010 bought in late march but OT at work is killin my boating) and have followed the Manual break in to the letter of the law (right or wrong) and have a question. Factory fill is still in it and looks clean and bright. above the hash by about 1/4 of an inch after the tilt, let sit and re-check procedure. My question is I have a trip I am going on in the the next week in the Colombia river and am wondering if I am better off changing it now as opposed to the 20 hr interval or just runnin it and doing it when I get home...water temp will be ~55 deg. No excessive idling anyway, not WOT for more than 5 min yada yada..will put about 5 hrs on her during the trip running and cycling rpm's per yamaha using the T8 for trolling...any input much appreciated!

Thx in advance..

Andy

 

[Woodrow246]

Re: 2002 f80 knocking

Bump:::anyone?