Bad connecting rod ?

[livinthelife]

I am new to this site as well as new owner of a v max. I purchased a 2000 model max with 22000 miles. I knew before buying that it had a slight knock in left front cyl. From what I have read it sounds like connecting rod. At idle you can't hear it but with a screwdriver up to the ear you can hear it at the cyl. The bike does'nt smoke and starts fine. Im planning on pulling motor and taking to my dealer mechanic he is very knowledgable with yamaha v-4's. My question is does this sound like a rod and what steps to make engine removal easier. I can get oem yamaha parts at cost but is there any aftermarket parts that I should be putting in instead like high comp pistons etc.:confused2:

 

[4gasem]

is there any aftermarket parts that I should be putting in instead like high comp pistons etc.:confused2:

Absolutely!

Pistons connecting rods and some good head porting goes a long way!

Sean Morley can guide you in the right direction. He goes by one2dmax and if you add @aol.com to that you have his email.

 

[hubeerjw]

Before you start ripping your engine out, I would look at your starter clutch.
It sounds like I have the same knock as you. I can hear mine at very low rpms. Search the forum for starter clutch replacement and see what you think. The starter clutch bolts are known to loosen up... I hope that is what my "knock" is from. I think the most you have to do is take off the flywheel to determine it that is the problem... so you might be out a gasket and some time... there are other guys here on the forum that should be able to give you a little more insight on this.

 

[livinthelife]

The previous owner checked the starter clutch it was fine. When you increase rpms past 1500 the knocking starts getting louder. I think it sounds like the piston smacking the head.

 

[lankeeyankee]

Does this knock get louder as the engine heats up?

Does the rythm of the knock speed up as you increase the RPM'S?

VMAX's are known to sling rods if you rev them past 10.5K

 

[Heretic]

The V-Max engine is not the quietest engine out there. I would have a good cycle mechanic verify (or at least get an educated guess) prior to taking the engine apart. Valves out of adjustment would make some noise too. If its truly a 'knocking c-rod' you shouldn't need a stethoscope to hear it, even at idle.

 

[livinthelife]

No it does not get any worse when it warms up. Yes the knocking rhythm speeds up as the engine does. You can here it without a scope.

 

[one2dmax]

Feel free to give me a call. 316-619-8411. If it's hitting the valves the sound will be intense! Drain the oil and see if you are panning for brass.

Now would be a good time for one of my 1300 conversions. I will also have a good stock engine available soon too (building a 1300 right now for that customer)

Sean

 

[Birdoprey]

If you rev the motor does the knock quieten some(as rpms increase)? And as you chop the throttle(as the rpms drop), does the knock get louder? This is typical of rod bearing problems.

 

[chainednitromaxx]

Sound like a rod knock spun bearing.Do not run the thing no more!You will probably need a crank as well unless you are ok with crank being repaired.I do not like repaired cranks,i vote for good used one.drop the bottom oil pan sump cover.you will probably find alot of metal in pickup of pump or just cut the oil filter metal off its not hard to find rod failure. john

 

[lankeeyankee]

Nahh VMAX's never throw rods these engines are bullet proof .... hang while i take another hit off this ......... ciggarette.. Does it sound like this ??
Hmm I had 3 engines have the same noise and all from the left front cyl..
I love my VMAX though :clapping:
But I will say I made it through the 08 season with no rods letting loose and my fastest 1/8 mile et on raw engine... http://www.youtube.com/watch?v=bRjlwThBreo

 

[Firewrench]

I have a question on the connecting rods too. My manual says that the rods will all be marked with either a 3 or a 4. All of mine are marked with a 5. :ummm: P2 on the crank is a #1. 5-1=4 or Green bearing?

 

[one2dmax]

Most of the rods we get are 6's but about any number is possible. On our reworked rods we don't use the code anymore but mic and plastigage them.

Sean

 

[Firewrench]

Thanks Sean. I figured that was the case as they have so many different bearings available.
Thanks again.