yamaha p50tlrq

[TownsendsFJR1300]

Plus 100 ^^^


The crank shaft is the heart of the engine.. Everything works to make it rotate...

I wish you WOULD ANSWER WHO RE- BUILT THE ENGINE and EXACTLY WHAT DID THEY DO TO IT.

If it's the same mechanic your dealing now, it should have been found when it was apart.

[Monsanto J F]

From your first post, it's been re-built already?

Who rebuilt it and did what exactly?

Something (mechanic wise it sounds) is not right.

In any case,

Top Dead Center or TDC is when the piston is at the HIGHEST POINT UPWARDS IN IT'S TRAVEL / stroke.

The issues with TDC having slop (major wear) is usually from bad BEARINGs likely at the crank(bearings worn, crank moves but the connecting rod/piston doesn't).

The rod bearings and possible the rod could be damaged and would likely be so MORE than the crank.

BTW, soaking the carb in cleaner alone will NOT clean it. it needs to come apart.

the first overhaul was last year. the compression was off in bottom #2 & #3 cyl and had water entering engine. at that time they notice the crankshaft had e little wear do to the water that entering, but said it would work fine. since that overhall last year. after overhaul no power at wot. at that point did fuel from top to bottom. finaly switch cdi box. still same problem.

i will try and make some pic later or check with my dad what was wrong with crankshaft. i will let ya guys now

[Monsanto J F]

Plus 100 ^^^


The crank shaft is the heart of the engine.. Everything works to make it rotate...

I wish you WOULD ANSWER WHO RE- BUILT THE ENGINE and EXACTLY WHAT DID THEY DO TO IT.

If it's the same mechanic your dealing now, it should have been found when it was apart.

the guy that did it last year is also the person how told me it`s cdi box, but don`t deal with him any more

person how help my dad last night works at a outboard shop. good friend of my dad

[TownsendsFJR1300]

Pic's and details would help.

As noted already, if everything is normal, just running crappy at WOT, (higher RPM's), your carbs are likely dirty.

Soaking in carb cleaner WILL NOT clean it fully. They need to come apart, jets pulled and cleaned.

[Monsanto J F]

Pic's and details would help.

As noted already, if everything is normal, just running crappy at WOT, (higher RPM's), your carbs are likely dirty.

Soaking in carb cleaner WILL NOT clean it fully. They need to come apart, jets pulled and cleaned.

hey i check every think last night.
we had this problem since last rebuild(end 2016).

we went true carbs, spark and compression so many times. last night after looking at the parts. i found the crankshaft had marks on them. like when your going to repair the crankshaft.

so i called the guy how did the first rebuild last year, who told me the crankshaft was good. he tried to repair the crankshaft. but t wasn`t done good or something went wrong. because the the crankshaft does not line up now(see pic`s). when he put i back the engine started and idle, but still had problems with spark or timing off. so he let me buy a cdi box $600.

But never accurred to me that the crankshaft because he told me it was good. now seing the crankshaft i can see way the timing is off.

a new crankshaft $1500-$950. can i also look into used crankshaft or just go for a new one.

my concern is do you guy`s agree with me do to bad crankshaft the timing is off or should i look into the other parts. every thing else is good. engine block no damage

also it was running on top cyl only. see pic
that`s why the spark plugs where like clean and no carb build up on them

[TownsendsFJR1300]

Holy crap...

Your #1 cylinder connecting rod is also BENT SIDE WAYS, notice the piston turned side ways?

99Yam and Rodbolt have used a company to rebuild crankshafts.
Either will post soon and give you the name of the company.

Your first "mechanic" must have put it back together like that. How it ran, I dunno. The rings should have grabbed a port and tore the cylinder as well. That crank needed replacement then..

For that rod to bend like that, I have no idea..

http://www.boats.net/parts/search/Ya...TON/parts.html

[99yam40]

Not many have the proper equipment to press apart and put back together a crank like that.

I do not think the rod is bent or twisted, just the angle of the pic.

could he have put it back together wrong? Yes it is possible, if he took it apart. we do not know that .
but I do not think we can look at a pic and say that is the reason your motor is not running properly.

OP tell us how you determined the timing was off on one or 2 cylinders and OK on one?

[TownsendsFJR1300]

99Yam, you had yours (crank) re-done when you re-built it.
http://www.boats.net/parts/search/Ya...TON/parts.html

Their pressed together, (the rods are one piece) same as yours (see link above)...

What company did yours?


And the skirts to pistons 1 and 2 are definitely offset.

[99yam40]

I would have to go find the name again, but this poster is not in the USA so he will not be sending it to NC anyway

[TownsendsFJR1300]

I would have to go find the name again, but this poster is not in the USA so he will not be sending it to NC anyway

Forgot about that, cancel..

For the OP, it is possible to re-build that crank, but the shop has to be equipped, have parts, etc. Very likely, won't be easy to find.

Another crankshaft would be the way to go..

Used probably as a new one is probably more than the engines worth..

[Monsanto J F]

okey meany thanks guy`s

[panasonic]

I would be inspecting your crank cases very carefully before putting another crank in. What ever caused that connecting rod to be bent like that put a terrible amount of strain on those cases.

[Monsanto J F]

I would be inspecting your crank cases very carefully before putting another crank in. What ever caused that connecting rod to be bent like that put a terrible amount of strain on those cases.

hey guy`s what do you think could have caused crankshaft to get bad like this.
any idea`s

[99yam40]

I see no way for rods to get twisted.

I still think it is the angle the pic was taken.

we still do not know what is wrong with your crank or if there is even anything wrong with it

[boscoe99]

I see no way for rods to get twisted.

I still think it is the angle the pic was taken.

we still do not know what is wrong with your crank or if there is even anything wrong with it

Agreed. I am not seeing anything untoward in the photos.