Blackout

Thanks for the info guys!

BTW, Stony Pond is ready for boat testing. So, feel free to come on down when you are ready. There is still spring setup to do, but the retrieve boat is in and so is the launch dock. The bouys are also in.

engineman351

Craig, Thanks for the pond update. I've got two .21 Tunnels and the JAE.12 rigger ready to go. Just need to make sure the batts are topped off. RC

advanced builder

I'm glad the old-timers, Spoke up. I got a spark plug T wench with my EZ starter.

Blackout

I took a look in my K30S, through the exhaust port, and the engine sure seems kinda dry. Is this normal for a gas engine or should I add a little 2-stroke oil through the spark plug hole before start-up? Also, do you guys run more oil in your gas for break-in? A always did with my jetskis and three wheelers.

Thanks.

Billk44

It is probably not dry. They do not look like nitro motors. No, run a standard fuel/oil mix and run her a little rich. If you run it too rich you will have a lot of messy oil in the boat. RCMK had changed from a very hard ring (very long break in) to a softer, quick seating type a while back. This motor should have this type of ring. Most mod motors seat the rings fairly quick. By the time you get your pipe / prop combo dialed in, it should be ready to rip. I run my motors very hard and have never had an issue. What prop have you decided on for the Lazer?

engineman351

Craig, Many builders actually take their new engine apart and check for oddites like missing circlips, ring fit, bearing fit, etc. (I am not one of those guys!!) I do, however, put some oil into the cylinder before cranking over a new engine (usually just some Marvel). I do not put any extra oil in the mix (8oz per gal) or whatever amount is recommended...but I would ignore any factory recommendations that say 4oz or less!! I once read the FAQ/Tips on QD's and I think I once read that break in didn't have to be more than 6-10 laps before you squeezed the trigger all the way!! I guess these gassers are not your fathers Nitro motors, eh?? The ring is pretty low tension and if they have the proper clearance end gap clearance (.004-.007 I think) you should be good to go. The Zen manual says 0.05~0.25mm (.002-.009") for end gap so that will tell you what works for a 'leaf blower'!!!

advanced builder

If you do pull it apart ,the only thing to watch out for is the ring has to go back in just right /or the brake will go in front of the exhaust outlet. If you look at your piston real close ,you will see a pin sticking out of the ring seat. the break on the ring goes their.

engineman351

Craig, What Neil is describing is called a 'pinned' ring. The 'pin' goes toward the intake. On Zens there is a little protrusion on the jug into the top of the intake port that is there to keep the ring ends from expanding into the port. Other engines may align the pin on an area of the cylinder that is solid (hard to do on a Zen!!) I do not know what a K30 ring setup looks like, but it sure is something to consider when disassembling/assembling an engine. There is also a bit of 'finesse' required when slipping the jug over the piston on these engines. You have to make sure the ring is aligned with the pin and that the taper on the inside bottom of the jug 'captures' the ring evenly as you push the jug down. If it gets cocked and the ring gets stuck it is very easy to snap a ring. After you do it a couple of times its pretty easy. Roger

advanced builder

I agree with Roger except the pin goes at the exhaust side. The bird beak or rise in the one port has to stay. All opening can be matched and enlarged Don't go too far inside as the liner wall has been treated with a fine dust and heat treated to get that shinny inside. So stay away from the inside walls JM2C

Canadian LoCo

if you guys would like some great info about gas engines MGB would be the best place for all
your gas engines great site great info.

http://www.modelgasboats.com/Zenoah_Teardown/

regards
luc

engineman351

Neil, Maybe this is why you are lunching some motors!!

From JBD:

In what direction should the piston ring gap face in the cylinder? I saw two groves in cylinder wall through exhaust port. Pulled cylinder and piston ring gap was facing intake side and groves in cylinder wall matched up with ring gap. You can feel groves with fingernail. Any comments would be appreciated. I am going to replace cylinder head case and ring or is something else causing problem. Motor had very little run time. This is a stock engine. I have three other Zenoahs without this problem, one stock and two modded.

Answer:

It has to be on the intake side as it cannot ride across a open port or it would fall out and tear it off. The ring does not(or should not)go past the roof of the intake so it is always riding fully on the cylinder wall.

Roger

Billk44

Roger,
Bingo, you beat me to it. The exhaust (side exhausts) is wide open. Ring ends in that area would cause serious problems.

engineman351

Bill, Now IF I could only beat you to the line in Gas Cat or Gas Mono!!! RC

Blackout

I have four Zippkit props to try. One is a 6717/3, I'd have to check to see what the others are.

I'm not going to open the K30S. I'll leave it stock for now. One guy on the dock mentioned a stock K30S would not be powerful enough for a Lazer 45....

I put a starter pulley on the flywheel. It was half the cost of a EZ-Start. It'll feel just like I'm running a nitro boat, just no glow plug driver to worry about.

Billk44

One of the keys to the mono props is no or low lift. 2614/3 runs very well on many monos. The 6717/3 may be a bit much depedning on the pitch profile. That motor is getting good reviews. Unfortunately, most folks don't specifiy if it has been modded. You can always try it and see how it performs.

advanced builder

I'M WRONG again, See I forgot all I knew. again.

engineman351

Craig, I took a few minutes and read the article that Luc provided from the MGB site. It is really well written and gives you very good info on disassembly/assembly of our gas type engines. (Thanks Luc for the link!!)

Canadian LoCo

your very welcome SIR I like that site lot's of good info
about engines and boat setups and all.

Blackout

You guys see this video yet? Same mono hull that Prop Circles is building...

[youtube]http://www.youtube.com/watch?v=WPWz4bE1e_U&feature=related[/youtube]

engineman351

Craig, My ears aren't so good...what was the speed?? And do we know what motor it had in it?? It just said LSG36. RC

Blackout

2011 IMPBA Elizabeth City SAW event - 82.75 MPH

Not sure on the motor.

Blackout

BUTCH THE BOATMAN engine and a BOB AUSTIN prop. Got this from the IMPBA record books. It's funny that the gas cats are only 2 mph faster than the gas monos in the straights...

gassertom

Is anyone going to the pond this weekend? With Craig's permission, we'd like to throw the 20 JAE and my "nostalgia" 60 Coyote in to see how they run and try and get our boating skills up to par with everyone else. Sunday would be best for us.
Thanks, Tom and Cindy

Blackout

Sunday is fine with me.

engineman351

This weekend looks great to test. Unfortunately I'm off to Tennessee to go to the NASCAR race at Bristol. Hopefully the weather stays good all next week...I really want to try the JAE.12 and the TS3 again. Tom, good luck with the Coyote. Roger