Jet boat stored 10yrs.

[scottyamaha]

My yamaha twin 135 engines have sat idle for about ten years while garages. I want to safely do as little as possible until I can confirm the engines are good(no cracked heads, etc). I have drained the gas, oil, and changed fuel filters. Is there anything critical that should also be done before attempting to start engines as to not cause damage. Again, they have not been started in about 10 years. Any help is appreciated!

 

[Scottintexas]

Glad to have you on board, where are you located?

Were the engines running ok when it was stored? Did you own it when stored or have you just purchased the boat?

I'm no mechanic and I'm sure some others will reply,
Since it's a 2-stroke there may be more involved but I would probably put some oil in the plug holes and try to turn the engine by hand to lubricate the cylinder walls/rings and hopefully get some oil on the crank/bearings,

 

[Bruce]

@Speedling, I believe this is a two stroke. Do you have any suggestions?

Personally I would want to spray something like fogging oil or penetrating oil in through the spark plug openings to lubricate what I expect to be dry cylinders. Also you need to make sure the carbs will feed oil.

 

[scottyamaha]

Glad to have you on board, where are you located?

Were the engines running ok when it was stored? Did you own it when stored or have you just purchased the boat?

I'm no mechanic and I'm sure some others will reply,
Since it's a 2-stroke there may be more involved but I would probably put some oil in the plug holes and try to turn the engine by hand to lubricate the cylinder walls/rings and hopefully get some oil on the crank bearings

Glad to have you on board, where are you located?

Were the engines running ok when it was stored? Did you own it when stored or have you just purchased the boat?

I'm no mechanic and I'm sure some others will reply,
Since it's a 2-stroke there may be more involved but I would probably put some oil in the plug holes and try to turn the engine by hand to lubricate the cylinder walls/rings and hopefully get some oil on the crank/bearings,

I'm the original owner, but was not there to see if boat was properly winterized. I was told it was hence dont want to put "big" money into the boat until. Thank for your reply.

 

[scottyamaha]

@Speedling, I believe this is a two stroke. Do you have any suggestions?

Personally I would want to spray something like fogging oil or penetrating oil in through the spark plug openings to lubricate what I expect to be dry cylinders. Also you need to make sure the carbs will feed oil.

Thank you. I going to do so.

 

[Bruce]

You also need to check the oil injection system, especially the hoses.

I am a fan of keeping the oil injection intact rather than converting to premix but I believe I would start those engines with premix until you were certain that the oil injection system is working.

 

[the MfM]

The carbs should be rebuilt. You could try to start it without rebuilding them but I would let it run for any length of time.

AND

If it hasn’t been done before I’d replace all the oil injection lines AND use metal clamps not the zip ties it came with originally.

It’s easiest to to remove the oil the pump from the engine when replacing the lines...makes it easier to get the lines/clamps on. Don’t lose the coupler between the oil pump and crankshaft. While the pump is off you’ll want to prime the oil system by using a cordless drill to spin the pump... Leave the spark arrestor off and watch until you get oil dripping steadily into the carbs.

If your just wanting to do a quick test start as mentioned above you could drizzle a little two stroke oil down each carb.


AND

I’d carefully check all the fuel lines or replace them sooner than later.

AND

New spark plugs, just because

 

[Speedling]

On my phone so i will be brief, but at 10 years anything with plastic or rubber especially that touches gas should get replaced. Fuel lines may be ok. I don't know of the construction. Oil lines replaced (they make kits)
Carb rebuilt is excellent idea as stated.
Possibly the reeds but you may be ok there. I forget the construction of them. Next you need to worry about rust on the inside and the state of head gaskets. You could pull the head off each side but i would try replacing other stuff and then fire it up.
Perhaps worth putting a wrench on the motor or even possibly by hand on the intermediate love joy and turn motor over a time or two. You may need to pull the pump shaft out and make sure that isn't binding as well.
Start the engine without and then if all is well put shaft back in. The liner may swell and bind up the impeller from sitting and oxidizing.
Let us know how it goes!

 

[Liveto99]

I would replace plugs, shoot a little fog oil in each as i did, turn it over to make sure it is free, and try to start it on premix. you can see if it will run for under $20. Use a friends battery also to test it, or adaptors from auto zone and your car battery another $6 But thats just my$.02

If you want to see if it has spark have your wife hold a finger in the spark plug boot and crank it over, you will know if it does.
(This place is so nice} don't do that it will shock her]

 

[Speedling]

I would replace plugs, shoot a little fog oil in each as i did, turn it over to make sure it is free, and try to start it on premix. you can see if it will run for under $20. Use a friends battery also to test it, or adaptors from auto zone and your car battery another $6 But thats just my$.02

If you want to see if it has spark have your wife hold a finger in the spark plug boot and crank it over, you will know if it does.
(This place is so nice} don't do that it will shock her]

Good point on the premix! Will need a few gallons to be sure all is well.