CMB 45 Evo 2/2 problem

[jasoncsc]

I have a CMB 45 Evo 2/2 that had ran less than 10 tanks, but already had the con rod big end seizure problem three times already. Everytime it happens on shore right before throwing the boat into the water. The mixture has been set so rich that on start the pipe would split out a lot of oil. I use 30% fuel with 20% synthetic lubricant. I am not full throttling the engine on shore when it happen. I had my engine serviced by the local CMB agent, and he even made the fuel inlet holes on the conrod bigger for more lubrication to the needle bearings. I just does not have a clue as to why this happen, and the local rep does not have a clue also. I got very disappointed about this engine. Before I dump this engine completely, I would ask for someone's opinion as to why this problem persists and would there be a way to cure this? ???

 

[izitbrokeyet?]

Dude,

I’m not certain of it, but on that motor, its possible the loose the crankshaft alignment pretty easily. This causes the needles/conrod/crankshaft connection to get loaded eccentrically (causing seizure).

Check out the following thread on how to fix it:

http://perso.wanadoo.fr/xavier.cardinale/D...nc_vilo_US.html

 

[Ian Inverarity]

When you say it is siezing, what is it actually doing? Locking up completely requiring dis-assembly or nipping up and stopping, but able to be re-started etc?

Ian.

 

[jasoncsc]

Dear Ian,

What I mean seizing is that the roller inside the big end of the con rod were jammed lock. This way the engine could not be restarted.

 

[Ian Inverarity]

Is this actually breaking needles or scoring the crank-pin and rod when this occurs?

Ian.

 

[EatMyShortsRacing]

Hmmm..

are you sure it is not just locking up on TDC???

EMS Racing Its the simple things that bite you on the ass

 

[nzmpba22]

a couple things did you put the motor apart and remove burrs etc and check the motor bfore you ran it? ...2 is the fly wheel wobbling ( if so crank not aligned ) ...3 check to see if disc not hanging up when you turn over motor by hand you will feel it clunk ( feels same as broken rod )

 

[Dave Marles]

Needles seizing is problem with the conrods that have oil holes on the 45 EVO2/2. Somehow the clearances or the hardening is incorrect. Get the very latest rod with the slots in it and use some good needles, INA or Torrington and you should have no more problems.

Dave

 

[Joe W]

Jason. Some of the Cmb 45`s had the Crank Pin machined too small about .230. This same engine had a conn rod that had small round holes to lube the needels. Now for the real problem.......... The small crank pin turned the needles Way faster than CMB ever wanted them to go.......( resulting in burnt needles) This was a brief NEW Design that DID NOT work...... The fix....... is a later model crank with a bigger crank pin approx .275 & and different conn rod. I would contact Tide Water Mfg. Ask for Bobbby or Art

 

[Dave Marles]

Joe W, The query was about the CMB EVO2/2. You are referring to the CMB CAM/HYDRO engine. The EVO 2/2 has a bigger crankpin than the EVO2 and the CAM/hydro engine. The problem with the rod is well known in European FSRV racing and is cured by using the latest rod.

Dave

 

[jasoncsc]

Dear guys,

Thank you very much for your very helpful insights. Dave I noticed that both conrods that I have seized (The one that comes with the engine and the one that was changed later) had small holes instead of the oil slot. I did read about this problem later in another discussion group. I wonder if CMB would replace my defective conrods, needles and crankpin....I mean, CMB should fix this and should have replace their defective parts, but the local importer of CMB just flag me "the bird" when I ask for a free replacement....

I was VERY VERY discouraged by what happened with my engine, and talking about that is my first engine bigger than 21 size frankly because of this problem I was too scared to go beyond 21 size... This engine ruined my visit to the pond for 3 weeks already, and I've had it. Now the Evo 2/2 sat stale for over 3 weeks already, still waiting for repair parts to arrive the local importer.....Even after I repaired this engine I would have no confidence on it no more....

Bye Bye CMB and hello MAC.....

 

[Dave Marles]

I would think the distributor should sort this out, but thats not really for me to say. If they don't, then send the parts directly to Mauro Braghieri at CMB in Italy. He will fix it.

Of course any engine can have problems but this is a good strong reliable engine when this problem is fixed.

Dave

 

[jasoncsc]

Dear Dave,

Thank you for your advice. The local importer, Nelson Wong of Hong Kong, told me that he had send defective parts to CMB for exchange but CMB never replace them for free..... I have never contact CMB so what I heard from the local importer maybe wrong.

Anyway I would love to try my luck with CMB, does Mauro have an e-mail address that I could contact? Can you also supply CMB's mailing address too? Thanks!

Regards,

Jason

 

[james irwin]

YES , A LOT OF GOOD IDEAS THERE , WHAT KIND OF FUEL ARE YOU USING . ITS ALL GOOD , JUST SOME IS BETTER FOR RACING THAN OTHERS , REALLY IT DOES NOT MATTER , JUST MAKE SHURE YOUR FUEL HAS A MIXTURE OF SYN , AND CASTER IOL FOR LUBRICANT , WE HAVE FOUND THE LIFE OF THE MOTORS WILL LAST FOREVER WITH THE CASTER OIL IN IT , WE LIKE A TOTAL OF 20 PERCENT OIL. 16 BEING SYNTHETIC, 4 PERCENT BEING CASTER OIL / REMMBER . THE ONLY THING YOU HAVE FOR COMPRRESION IS THE OIL . SO DONT LET ANY ONE TRY TO CONVINCE YOU TO USE LESS THAN 20 PERCENT.

 

[jasoncsc]

Dear James,

I am using fuel with 30% nitro and 18% syn oil. So should I mix in caster oil to the fuel before I use?

 

[Ian Inverarity]

Yes!!!!

Jim says to use 4% castor, personally I use 7%. Just using straight synthetic is not a good idea.

Ian.