CMB 45 Rod Failure

[Jay Stone]

I too had one of the CMB 45's with the ROD problems. I have since sold the boat and engine.

While I'll admit I haven't run a whole bunch of MAC Engines, I can tell you that I have seen ANDY and COMPETITION MARINE take great care of their customers.

I have seen very few instances of problems with the engines, but in every single case the problems were taken care of immediately.

I am in the primary stages of building a new sport 40 and plan to order one of the new MAC 45's when I am ready for it. I always order my props and shafts from CMDi and CUSTOMER SERVICE is always Priority #1.

 

[craig]

Thanks

Andy i wish we could get the shop where i bought this from to help because it goes in the stiff **** basket next engines will be MAC.

 

[Flyin Rat Sass]

Not having had the advantage of examining the parts closly (microscope ect) the area that it broke suggests a rotational force close to the crank,such as the clearance problem mentioned or what came to mind was needle bearing seizure (foreign material entering through enlarged [or stock] oil galley)unless there's a serious material defect at that point alone, it would be difficult to break it there .try to break a stick in your hands at one end ,you must apply laterial force at that end primarily.the stick thing also indicates another possibility the crank pin is not true ,bending the rod back and forth twice per rev ....wont take long for these results.

Just my observations,sorry for the misspellings and faulty puncuation(I will at years end submit a post with all the omitted commas,periods capitol letters ect. that i missed throughout the year)

 

[AndyBrown]

I always order my props and shafts from CMDi and CUSTOMER SERVICE is always Priority #1.

Hey John, thanks for all that great press, but we ain't that good.

But we do try!

 

[Wild Bill]

I had a good look at my bits on the weekend. There is wear on the crank between the two bearings. My thought is that the crank is flexing and stressing the rod to breaking point. With the continual movement of the crank, the result is the same as trying to bend the rod constantly and it fails just above the big end. I also found that the brass bush in the top of the rod has come adrift. I believe this also points to the flexing and the rod trying to 'bend' with the forces.

If my memory isn't too shot, I believe we had a similar problem with the Picco 67's a while back. Their problem was that the crank pin broke off. Both these engines are the same confirguration so would share common complaints.

I know we fix a similar problem with the Picco Hydro 90's by making a new bearing housing and fitting it with 2 big bearings to support the crank. Not being experienced in any form of engineering, would it be possible to retro fit any sort of support bearing in these 45's?

Anyone with the 'knowledge' have any thoughts on how to fix this?

Bill Annabel.

 

[Ian Inverarity]

Bill,

When you say wear on the crank can you descibe what you see? It would rub on an aluminum case so I would be surprised if a hardened steel crankshft would wear? :huh:

When you say supporting the crank in two big bearings do you mean 2 big bearings at the rod end and the normal size bearing at the other? Like some people do to OPS 45's? In that case a new front housing is made to accomodate the two large bearings. In the 45 hydro there isnt enough material in the case casting to do this.

Ian.

 

[craig]

Hey guysI looked at my needle roller bearings last night & found what looks like hot spots only on half the needle. may be the con rod or the crankshaft is flexing

 

[Ian Folkson]

Pictures of the new CMB45RS

on

www.iansboats.co.uk

 

[craig]

I mentioned my misfortune to a fellow boater and he told me that Mac 45 has had crankshaft failures & 67 have had crankcase problems he said andy brown came to the party and replaced them.Has anyone had the same problem with these engines

 

[Don Ferrette]

I mentioned my misfortune to a fellow boater and he told me that Mac 45 has had crankshaft failures & 67 have had crankcase problems he said andy brown came to the party and replaced them.Has anyone had the same problem with these engines

Nope. Mine are running fine. Nobody is perfect & things happen. Bottom line is, like I previously mentioned, good customer support from the retailer. This is something that Andy & CMD is known for but perhaps Tidewater has not fully grasped the advantages of return customers....... <_<

 

[GMCSW7]

Was getting my boat ready for a 1 May race in Evansville. Brand new 2004 CMB .45 with 1/2 a gallon of 50% nitro. Was in the process of breaking it in. Gave no indications that it was going to do this.

First day running it!

Has anyone received any response from CMB or Tidewater on these failure's?

Unfortunatly i bought the motor before seeing this tread.

here are some pic's

 

[GMCSW7]

another :angry:

 

[GMCSW7]

more!

crank penetrated the casing

Steve

 

[GMCSW7]

last one

How are the 2003 CMB .45 doing?

Is this problem a batch problem or is it unique?

Contacting Tidewater on Monday!

 

[craig]

STEVE

YOU WILL GET THE SAME RESPONSE WE GOT FROM TIDEWATER WE WERE THE ONLY TWO IN THE WORLD THAT HAVE THIS PROBLEM WE HAVE AUSTRALIAN CMB AGENT LOOKING AT OURS

 

[GMCSW7]

ALL,

Contacted Tidewater and explained what happened.

They asked me to ship it back to them and they would take a look at the motor. I explained to them that I left the motor untouched after the failure and it was not modified in any way. They were very willing to help out. They have only heard rumor's (through other people) that there is problems with the 2004 .45 cams, only two people have contacted them about the rod failures.

Hopefully this will get the ball rolling to see if there is a problem with the 2004 45 CAMS.

Will keep you posted.

 

[Don Ferrette]

ALL,
Contacted Tidewater and explained what happened.

They asked me to ship it back to them and they would take a look at the motor. I explained to them that I left the motor untouched after the failure and it was not modified in any way. They were very willing to help out. They have only heard rumor's (through other people) that there is problems with the 2004 .45 cams, only two people have contacted them about the rod failures.

Hopefully this will get the ball rolling to see if there is a problem with the 2004 45 CAMS.

Will keep you posted.

Very good & best of luck. Perhaps they will begin to acknowledge there is a problem & help you guys out.

 

[GMC7]

To ALL:

Customer service was great with Tidewater Engineering and Machine Company. They are replacing my motor free of charge and they sent it next day service.

 

[BigBryon]

DO THEY STILL HAVE A WEB SIGHT

 

[Jay Stone]

I have been running a CMB 67 Greenhead in my Crapshooter.

This past weekend I was running the boat in open water and had it just shut down after making a POP sound.

I checked the plug, it was good. I checked everything, and the engine turned over no problems. So we tried starting it again, and fuel was spraying out of the carb. Very strange. So we stopped, and I pulled the engine. Took the back plate off to inspect the drum rotor - everything looked great. Put it back together and turned the engine over by hand. It turned over so easily, NO COMPRESSION. I pull the water jacket and head button to find a HOLE in the top of my piston. There was no debris in my engine at all. YAY!

About a website for TIDEWATER.. They no longer have a website..