fryfrog

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I now need to break in a 23cc marine gas 2 cycle engine and have a couple of questions. i tried a search or three, but am not entirely sure what search words to look for and most of what i turned up was totally unrelated that i could see.

1.) what type of 2 cycle engine oil should i use? marine 2 stroke for outboard motors or 2 stroke oil for linetrimmers, etc. i believe the marine 2 stroke oil is probably designed for lower temps and lower rpms than would be found in a marine model engine, but i would also think the line trimmer type oil is designed for much higher temps than one would find in a water cooled environment. any recommendations on brand? the person i bought the boat from suggested honda hp2 oil, but i haven't been able to easily find it (granted i've only been to walmart and home depot and its only been one outing).

2.) during the break in, is it possible to do this on a marine engine without doing it in water? i have an ice maker tap that i have been using to cool my nitro boat and it cools the engine better than it would be on the water. but the engine is under absolutely no load. would this be good, bad or not matter for a gas engine breakin? i'm going to visit the lake house this weekend, but it would be easy to run the engine for short bursts with a cooling off period at home where there is no water. the zenoah manual says it doesn't need a break in at all, but i believe this is a modified by b. h. hanson engine so perhaps it wouldn't hurt to do a breakin

**if you can point me to someplace i should be looking, i don't have a problem with reading

Ross143

My Feedback: (7)

1) Use a high quality 32:1 oil such as Amsoil, or a linetrimmer oil.

2) Gas engines do not require a break in procedure, just go easy the first few runs. It would be best to "break in" the engine under load, granted you can cool the head out of the water, the propshaft, etc. would get hot too, and you wouldn't be accomplishing anything. Revving it under no load could cause damage.

Hope I've helped some.

Cheers

RcBoatLover

My Feedback: (1)

I know with nitro engines you want to break it in at it's normal running temperature. The best way to do this is run it in the water. If you over cool the engine the parts will not expand the way they are ment to be. This will cause the pistion and liner to ware faster than normal. As for the gas engine... I think Rossi 143 is right. You don't have to break it in. Just take it easy on it for the first few runs.

fryfrog

My Feedback: (1)

thanks for the info, i don't think i will try and break it in out of the water. and i'll definatly take it easy for the first gallon. would it be better to take it easy in 5min intervals? or just run through a whole tank (20min+)?

Doubledog

My Feedback: (48)

I've brought the question about two stroke oil up with some top outboard builders a few months ago & a lot of them swear by the Penzoil. Though not many kicked the idea of using another brand, but make it sythetic.

crrcboatz

My Feedback: (34)

DO NOT use a synthetic oil in your gas to break in a new motor. Amsoil IS synthetic. Use a conventional oil at about 6-7 oz per gal. to do this. AFTER break in,about 1/2 gal or so on a rich mixture, begin to lean the motor a little at a time keeping it on pipe. Donot over prop it but rather something that will let the engine not work too much. You can use the synthetic AFTER breakin with no problem. I use Amsoil.

Curt

fryfrog

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Okay, so i think i'm about half way through the break in and i have a few problems (minor, i think easy to fix). The water cooling system is slightly lacking i think, and here is how i plan to correct it. the cylinder is getting cooled very well, with JUST it hooked up there is a good amount of water pressure even at idle. coming out the side of the hull, it throws the water in a stream about 3-4" long. when its hooked to the header, then to the exaust pipe it just kind of dribbles out, maybe traveling 1".

after running for more than just a couple min, it is blowing steam (not good). its water after it leaves the cylinder, but steams up in the header and exaust pipe. most of the time, just idling for a bit would bring water to it, but it is way to hot. it melted the clear hoses once, i trimmed them and re-fitted them and the next time it not only melted the pipes but the o-ring seals as well.

to correct this, i am going to put 2 new water pickups in the trim tabs closest to the bottom of the v and add a 2nd water pump. i also plan on having the rudder slightly modified. the water pickup in the rudder is on the right side, so when the boat turns left there is NO water pickup because there is no water flowing by it. i think a simple slightly angled drilled hole to the same point as the opposite side would work (instead of going straight back from the front of the rudder, it would come in at an angle so it was most useful during a turn). i plan on finding a machine shop to do this as i don't have the equipment to hold the drill or rudder steady enough.

now, 3 pickups, 2 pumps and 3 things to cool. i was thinking 1 trim tab pickup + rudder -> 1st water pump cooling the cylinder. 2nd trim tab water pickup -> 2nd water pump to cool header and exaust. if the rudder drill actually works, it may be better to put both trim tab pickups on the exaust as it really was the problem child. even when turning when it loses the water stream, it picks it back up as soon as the turn is over and the water stays pretty cool.

the problem with the exaust is that it uses o-ring seals to make the water cooling work... and they need the water cooling to keep from melting. i suppose if the oring seals were high enough temp, i could skip the 2nd water pump and just have pickups in the trim tabs. most of the cooling would be needed during runs anyway, not idle.

any comments are welcome, finding the water pump has been the hardest part, but tower hobbies seems to have ONE (prather) and it looks exactly like the one that is in there. Marine Specialties has it also as well as water pickups and i THINK the orings for the exaust manifold / pipe... but i suspect they are just standard orings and i'm going to see if the auto parts store has some high temp ones.

the other thing i really need is some good high temp tubing. after it melted, i ganked about 1.5" from my dad's outboard engine (lucky it had about 1.5" to spare on the fuel tank pressure line, it was hooked right to the crank case so it was at least decent temp). i had it ONLY hooked to the cylinder, and it wasn't having any problems. couldn't hook to exaust manifold or pipe because at this point the orings were blown and water was going into the exaust and the hull. i was thinking of using automotive vacuum tubing since its made to hook right to the block and that is VERY hot. any other materials to use? can you get high-temp orings?

you can see the two important things below, first picture is the current water tube routing and the 2nd is a picture of the rudder with water pickup on the right side.

75Blazer

What about using a TEE fitting to run separate cooling lines from your pump. Maybe one from the pump to the cylinder head then to the muffler, and the other directly to the header (to give it a fresh supply of cool water rather than pre-heated water out of the cylinder head) and then also on to the muffler? Just my 2 cents.

fryfrog

My Feedback: (1)

i did think about that, but here is my reasoning for a 2nd pump and seperate pickups for the header/pipe. the cylinder is going to be the most expensive thing to replace. when the pipe over heats, all i lose is 4 o-rings that cost like $4 maybe and the plastic water tubes (almost free). if something fails and the cylinder dies, i can only imagine what will happen and how much it would cost to fix.

also, i believe the cylinder is VERY low flow resistance (as seen by the dramatic increase in water flow output). i think at this point i will probably drill the rudder and use that with pump1 for JUST the cylinder, and pickups 2 and 3 in the trim tabs will join with a T and goto pump 2. from pump 2, i'm not sure if i would use a T again and go parallel to header/pipe or just go series. parallel sounds better, feeding both devices cool water. but then i have to have ANOTHER T to join and dump over the side... maybe more flow resistance and complication than is neccessary?

fryfrog

My Feedback: (1)

I forgot to mention i'm having trouble finding water pickups and the pump at the same place. the only one i can find it at is marine specialists (they have a 1/4" and 1/8" pickup as well as a pump) but their price list is from 2000 and truthfully, their online website kind of sucks. anyone have a favorite place to get boat parts online? there are not a whole lot of hobby stores that i know of in my area, the only close one went out of buisness or something a few years ago.

crrcboatz

My Feedback: (34)

Do a search for
Rocket City Racing and contact Bryan there. They deal in boating only products. Their phone # is 321 217-4588. I promise you they will take care of you. DO NOT place an order on line as it will be held up though.
Brian is also an accomplished boater and can help you with anything. Tell him Curt Risner sent you there. He has gotten a few bucks from me over the last 1 year!!

Curt

fryfrog

My Feedback: (1)

thanks, i called them on the phone and ordered the stuff i hadn't already ordered from towerhobbies. got 3 stainless steel bulkhead fittings, 2 water pickups, 10 o-rings and a brass T

fryfrog

My Feedback: (1)

would it be better to run a 2nd crank case pressure pump off a 2nd tap on the engine or is just running a T off the 1st (only current tap) enough do you think?

Ross143

My Feedback: (7)

Try it with the one tap first. Don't drill any more holes in that thing than necessary. A second tap can always be added later if it is needed.
Good Luck