310 Sundancer Thread (2007 & newer)

[A1308]

i have two Mercuriser 350 on my 310-2007 and i am having problems with compressions on one engine. The mechanic told me there's nothing to do about it but i wonder if anybody here has any recommendation before i give up.

2 years ago i did a compression test with these results:
COMPRESSION TEST
PORT ENGINE : HOURS 201
1) 180lbs 2) 170lbs
3) 175lbs 4) 145lbs
5) 145lbs 6) 180lbs
7) 180lbs 8) 163lbs

Last month the result was much lower:

COMPRESSION TEST (PORT)
2) 168lbs 1) 140lbs
4) 125lbs 3) 130lbs
6) 138lbs 5) 141lbs
8) 149lbs 7) 165lbs

I have no idea what may be the problem i will appreciate any guidance or ideas maybe ask the mechanic to do some attempts to improve it - the engine started to consume more gas and the max RPM i can now get to is only 4250 - about 15-20% less then my other engine..

Andrea

 

[Hifirush]

Ask your mechanic to do a leak down test. This will tell you (usually) where the loss of compression is. If it's valves, the heads need to come off and do a valve job. If that is the case, have him look at other systems of the engine to see if anything else needs freshening up while its disassembled. Hope this helps.

Matt


Sent from my iPhone using Tapatalk

 

[stephenm27]

...check for water intrusion in upper transom housing (steering pin) - I had to get mine redone after it was rack-stored since the seals had dried out. When you do sea trial then do some high speed reverse - that will push water hard on the steering pin seals and pull the stern down - making it more visible if you have water intrusion.

So I flew to inspect this 310 out today and here's the condition I found the steering lever in (both were in similar states):

For a boat that has been used in salt water for (only) 1.5 yrs and has been dry-rack stored, this seems to be evidence of excessive (salt) water intrusion through the transom to me. A deal breaker for me given the anticipated cost to replace.

 

[kaz911]

So I flew to inspect this 310 out today and here's the condition I found the steering lever in (both were in similar states):



For a boat that has been used in salt water for (only) 1.5 yrs and has been dry-rack stored, this seems to be evidence of excessive (salt) water intrusion through the transom to me. A deal breaker for me given the anticipated cost to replace.

yes that looks like water intrusion on steering pin - but a picture "in the hole" by the steering pin would clarify it better. You can fix it cheap with a "kit" - at about $1000 / engine - but requires drilling in the outside transom. Best way without drilling is engines moved enough to make space for taking all off - and then replace the steering pin with the later generation SS version. But a two-engine out operation will set you back $3000-$7000 dependent on how nice your mechanic is. But it is a great negotiation point.. so don't write it off yet if everything else is working great.

 

[Shtmetal]

You might want to look into tbe V drives instead of stern drives model. Yes the v drives burn more fuel and are not as fast but they are virtually problem free and great for close quarters. People will argue this both ways but for me V drives

 

[stephenm27]

You might want to look into tbe V drives instead of stern drives model. Yes the v drives burn more fuel and are not as fast but they are virtually problem free and great for close quarters. People will argue this both ways but for me V drives

V-drives aren't a consideration for our needs/wants (Axius, freshwater-only exposure). For obvious reasons, I would never attempt to own/maintain BIII's in a saltwater environment.

The boat in question had started its life in freshwater but was taken to FL about 1.5 years ago. Unfortunately, that short time has rendered some significant impacts on it.

The search continues...

 

[kaz911]

V-drives aren't a consideration for our needs/wants (Axius, freshwater-only exposure). For obvious reasons, I would never attempt to own/maintain BIII's in a saltwater environment.

The boat in question had started its life in freshwater but was taken to FL about 1.5 years ago. Unfortunately, that short time has rendered some significant impacts on it.

The search continues...

You can get leaky seals on fresh water boats - and eventually the steering guide pin will rust as well. Keep you boat on a lift - and at least on the models before stainless steel steering pins - the seals can dry out - and you will get water intrusion.

That is why peeping INTO the hole is important - then you can see salt deposits inside if the seals are leaking in salt water - and you can sometimes see mineral deposits in fresh water.

 

[stephenm27]

Ok, so I'm on to the next 310 candidate and we're very close to a "done deal". I've inspected it, the survey came back today with a few minor items...one is the Fireboy automatic fire extinguisher in the ER is due to be replaced. Specifically, the gauge is indicating in the "red" (as opposed to the green). Question is, does anyone know the cubic ft size Fireboy that SR installed in the 310? Unfortunately, the surveyor's picture doesn't show the model #.

 

[kaz911]

Ok, so I'm on to the next 310 candidate and we're very close to a "done deal". I've inspected it, the survey came back today with a few minor items...one is the Fireboy automatic fire extinguisher in the ER is due to be replaced. Specifically, the gauge is indicating in the "red" (as opposed to the green). Question is, does anyone know the cubic ft size Fireboy that SR installed in the 310? Unfortunately, the surveyor's picture doesn't show the model #.

CMD-4MR or CMD-4MR-RLY are the partnumbers. The CMD-4MR-RLY is the one is a 2008 with Genny I think. Only way to tell them apart is to take the front cover off. The RLY means RELAY - which will keep your genny from running or stop it on alerts. Genny should not run if Fireboy is in RED condition.

They have a date stamp from the factory - and runs 5 years from production date. So watch out when you buy a new one you don't get one that has been on a shelf for too long.

 

[stephenm27]

CMD-4MR or CMD-4MR-RLY are the partnumbers. The CMD-4MR-RLY is the one is a 2008 with Genny I think. Only way to tell them apart is to take the front cover off. The RLY means RELAY - which will keep your genny from running or stop it on alerts. Genny should not run if Fireboy is in RED condition.

They have a date stamp from the factory - and runs 5 years from production date. So watch out when you buy a new one you don't get one that has been on a shelf for too long.

I'm actually looking for the automatic fire extinguisher part # in the ER--not the CO monitors in the cabin...though I've also mandated the CO detectors must be replaced as well based on their expiration date.

 

[kaz911]

sorry early morning for me *G* - don't know the part number for that. And my boat is still on land waiting for parts. so hard for me to check. (New Risers after a 7 year run...)

 

[Shtmetal]

I have a 08 310 sundancer with v drives. I recently noticed a round opening in my transom that doesn't go all the way through of course. Its below my swim platform on the port side. It has a shiny disc inside of it. Any idea of what this is?

 

[MancaveII]

Can you post a pic?

 

[BigBoysToys]

I noticed on one of the diagrams in either the owners manual or the parts manual for my 08 330 that in some configurations there's a through-hull there with a seacock. If memory serves me its the discharge for the waste tank. Hopefully someone can confirm on that.

 

[JimG]

I noticed on one of the diagrams in either the owners manual or the parts manual for my 08 330 that in some configurations there's a through-hull there with a seacock. If memory serves me its the discharge for the waste tank. Hopefully someone can confirm on that.

Yes, that is where the discharge would be, if equipped.

I'm wondering if Shtmetal has the through hull with a plug and just not the seacock.

 

[Shtmetal]

Thanks guys that's exactly what it is, but there is no plug just a seacock. I bought the boat last July and I'm still finding new things.

 

[JimG]

Thanks guys that's exactly what it is, but there is no plug just a seacock. I bought the boat last July and I'm still finding new things.

Thanks for the confirmation!

Next time a picture would tell a thousand words! :thumbsup:

 

[jiama]

Hey this response is probably late, but I'm in the process of resealing my manifolds elbows and risers on my eight year old 2007 310. Boats out I found an oil leak coming from somewhere pulled engine to find, ended up being a seal around timing belt housing. My mechanic told me my manifolds and risers all looked good, resealed them. I religiously flushed my engines always for eight years I think it makes a difference. I only use fresh water to flush. Hope this is helpful. Goodluck

 

[dmorris800]

Hi guys, quick question, i noticed that both port and starboard battery switches are on or off. Do you guys turn off one of the switches when on the hook or overnight? On the 260 i would just switch to battery 2 on the hook and both for starting yhe motor. Thanks in advance. Dave

 

[kaz911]

Hey this response is probably late, but I'm in the process of resealing my manifolds elbows and risers on my eight year old 2007 310. Boats out I found an oil leak coming from somewhere pulled engine to find, ended up being a seal around timing belt housing. My mechanic told me my manifolds and risers all looked good, resealed them. I religiously flushed my engines always for eight years I think it makes a difference. I only use fresh water to flush. Hope this is helpful. Goodluck

I just did my Elbows - riser-extenders & manifolds looked perfect. 2008 boat - First in FL on Lift - then in the UAE for 3 years in the saltiest water of all. So 7 year old boat - and first change of elbows.

/k