Fuel for OPS .21 3.5cc

[Jim Zelazny jr]

I recently bought an entire boat and radio at a local yard sale for only 20 bucks.Although it looks to have sat around for many years and is not modern,looks worthy to get going again.I bought fuel for my airplane motor,15% Omega at local hobby shop which is all they carry.I was told the boat engine requires at least 50% by the hobby store people.But I got it fired up and screaming using the 15% before spending money on a boat I did not know ran at all.Started right up,idled and really wound up RPM`s.I had water running through the head for this test.Radio works fine after replacing all batteries.Nice solid well built boat.I had to make my own starter using a garage door cable pulley and portable drill.Just ordered an RC starter online.I can not seem to find info on the fuel I can use for this motor and was thinking 30% as I am newbie with these boats and do not want to fry the engine up.But online stores will not ship to NY or I cant find what I need for reasonable price.Some advice would be appreciated.Motor is was determined to be an OPS .21 3.5cc after sending photo to OPS company.

 

[Greg Rowe]

Get ahs of John Otto at Technology Hobbies he will make what ever % you wish, but your on the right track 50 to 60%
Have fun with your new boat
Greg Rowe

 

[Jim Zelazny jr]

Thank you Greg...something I can look into rather than guess.Many opinions about fuels out there,I just need the basics without burning it up.
Jim

 

[Grimracer]

I would run it on 15%..

Grim

 

[Geraghty]

Thank you Greg...something I can look into rather than guess.Many opinions about fuels out there,I just need the basics without burning it up.
Jim

If all you are going to do is run for fun there is nothing wrong with 15% fuel....believe it or not there is a power difference between 15 and 50% fuel but not as much as you think....You will get a lot more run time with tank of 15%....You got a OPS side port .21 ,a Muck Streaker mono and a International products pipe....You hit a home run for $20.00.....PS:That is a great pipe....
If you decide to race just learn how to start and drive in lane 2-3 and finish all your heats and you will be surprised how often you will go home with hardware running 15%....

 

[Terry Keeley]

If all you are going to do is run for fun there is nothing wrong with 15% fuel....believe it or not there is a power difference between 15 and 50% fuel but not as much as you think....You will get a lot more run time with tank of 15%....You got a OPS side port .21 ,a Muck Streaker mono and a International products pipe....You hit a home run for $20.00.....PS:That is a great pipe....
If you decide to race just learn how to start and drive in lane 2-3 and finish all your heats and you will be surprised how often you will go home with hardware running 15%....

Sure it's not an Irwin pipe? And ya, great advice, run it on 15% and have fun!

You might want to look at changing the bearings...

 

[FloridaScaleBoater]

Boat looks to be an old Youngblood hull.
Engine looks like an OPS 3.5 speed.
Before running the engine any more, I would go through the engines internals and replace the bearings, something that has been sitting that long will need them replaced.
Fuel, as suggested, if you are just playing (not racing) any % will be fine, but look for something with 18% oil,,, quality oil!!
John Otto @ Technology hobbies will mix any % and ship in quarts.
BEARINGS first though

 

[Jim Zelazny jr]

All great advice here !! I have decided to run the 15% until I become more serious about this hobby.
Sure looks like fun and for now,want to take things slow.
The motor was checked out by reputable hobby store guys here in my local area.They observed the engine and said whoever owned it took care of it and stored it with some sort of oil.They said it turns nice and clean with no signs of wear ,grit or bearing issue.When I ran it on 15% Omega...to me,this thing sounds insane...clean,nice idle and RPM was almost scary.Seeing some smoke from the exhaust tells me it was not too lean.I think 15% is a safe start for me.Going to go through this boat carefully,test radio system to be sure it does not fail.Radio is older Futaba 4 channel...servos work nicely as well as my airplane Futaba...no signs of issue there.New batterys installed...looks good.The radio box was clean and dry...well sealed up.
Other than old...appears to be ready to run.I will try to get a video and share soon as I can get organized.
Thanks for all the advice here...to be continued.
Jim

 

[Grimracer]

Some things to ponder.

NEVER open up the throttle wide open on shore. If you do you will break the motor. (you can not turn this like a airplane engine)

If the boat idles VERY CLEAN its probably lean and its best to just open the main needle 1/4 turn

If the boat stalls on the water its very likely lean.. keep in mind if turning the main needle out does not solve this then the motor might need new bearings.

RC boating is very much.. start, launch, test, beach, repeat...

have fun

Grim

 

[Jim Zelazny jr]

I did not go wide open but only to see how it reacted to throttling response.I know better than to go wide open without a load on the prop.A few quickies and was enough to tell me IT RUNS.
Waiting for an actual engine starter from Ebay...this home brew pulley/drill is killing my wrist Guess I have to spend some money...haha.By the way...after the engine run,touched the head and was surprisingly cool.Running the water works great. I still need to fabricate a pickup tube and have it pretty much ready to make up...seems straight forward.I have mechanical skill so these things are easier for me to figure out PLUS I have this forum !!!
Thanks again...will post when I have everything ready for a test run and see what you think.
Jim

 

[brad nichols]

Nice boat and it is a Muck. Get some 1/8 brass tube and a brass strip to solder to and bend tube to pick water up from the right side of the prop. I still have an OPS side exhaust and some parts. Hull may be a little noisy as it has a solid mount, they are all rubber mounted now. Can't see what you have for a drive setup, but make sure you grease the cable and shaft. You want more oil in the fuel as more lube will keep your motor alive longer. Welcome to the hobby!!

Brad

 

[Jim Zelazny jr]

Brad,
Thanks for added advise and you read my mind.I have brass tubing and a small brass plate to mount on the hull where there is already a hole where I believe the intake used to be.On the right side even.
Will get this done soon and post it here in case it may not be good...open to all advise.I feel same way about fuel...rich better than lean...although that can be bad too to some extent.
Oh...drive system to ME reminds me of a snake you use to clean drains for plumbing...very similar shaft,flexible like.
Jim

 

[Mark Poole ModVP]

Good advice on the fuel. No sense in spending a lot of money on high nitro fuel for fun running. When I first started I ran 25% and my boat would run all day with no issues.

 

[Geraghty]

Sure it's not an Irwin pipe? And ya, great advice, run it on 15% and have fun!

You might want to look at changing the bearings...

Terry,No I believe that is a IP pipe...[Irwins look a bit different...the converging cone on the Irwins are a bit steeper and the stinger was shorter]..I had several of both.... IP sold to Muck....I don't know if Muck is still making pipes....The boat is a Muck Streaker which also had me thinking the pipe was also a Muck or IP.....New bearings would probably be a great idea....I thought if the previous owner ran it on 10-15% and cleaned it out good the bearings might have survived....The new owner said he started it and it idled so I thought there is a good chance the bearings are probably still serviceable...
I was never that lucky as to find a buy like that at a garage sale...lolol
Rod

 

[Terry Keeley]

Terry,No I believe that is a IP pipe...[Irwins look a bit different...the converging cone on the Irwins are a bit steeper and the stinger was shorter]..I had several of both.... IP sold to Muck....I don't know if Muck is still making pipes....The boat is a Muck Streaker which also had me thinking the pipe was also a Muck or IP.....New bearings would probably be a great idea....I thought if the previous owner ran it on 10-15% and cleaned it out good the bearings might have survived....The new owner said he started it and it idled so I thought there is a good chance the bearings are probably still serviceable...
I was never that lucky as to find a buy like that at a garage sale...lolol
Rod

There ya go, never knew IP/Much sold a pipe that looks (to me) exactly like an Irwin pipe.

Hmmm, I wonder who came first?

And I wouldn't care what the hobby shop dude said, a motor that's been sitting for 20 years or more will have congealed oil stuck to the bearings. Start it up, a ball skids just a bit and it'll go soon after.

Then your OPS 21 is a paperweight, and the hobby shop dude will gladly sell you a new motor for $400.

Just sayin'...

 

[happybradboating]

Be sure to pull the driveshaft and put grease on it. Then run WD40 and oil through the motor. Then remove and dry of the drive shaft. Then repeat. The mixtures on oil varies on what boaters brew up!

 

[Jim Zelazny jr]

All good advice here.
This week I will go through this and prepare a run.The entire setup looks very sound and solid to me mechanically.I still need to mount the water intake and receive the new starter this week sometime.Then see about finding a nice place to run it.Here in my area is nothing but water...just need to make sure someone is not gonna yell at me.Locals in this hobby are too far away.
Jim

 

[Jim Zelazny jr]

New starter arrived yesterday and tested it out on the boat today.What a huge difference from my home brew setup.The engine starts nicely,idles well and tunes fine.I allow it a bit on the rich side and adjust for good response.However,it hung about 1/4 throttle and had to pinch off the fuel line to shut it down.The throttle linkage works perfectly and can see it was closed looking in the carb intake port so looks more like an air leak.I pulled the carb a few days ago because I noticed it was rocking or turning as if it was loose.Pulled the nut off and that pin with a small groove in it to check it out.Noticed the previous owner had applied some RTV sealant around the carb mount...cleaned it all off and reset the carb,but it does not seem to tighten well enough in my opinion.I made an attempt to try some teflon tape,but that was not working out too well.I think I need a new PIN ? Where do I get these pins and what is the proper term for it? Searching internet has not worked well as I do not know the proper term for this pin/nut.The carb looks to have a small groove in the mount where the pin looks it is supposed to fit into...or is the groove not supposed to be in the carb? I suppose I could use RTV sealant although not the proper way to fix this in my opinion.Last thing I need is RPM`s to be 1/4 throttle when I go test in water.Someone said it looks like a Perry carb...I agree.
Jim

 

[Jim Zelazny jr]

Looking at images of similar carbs,I now see the groove on the carb port SHOULD NOT be there.
Mine has grooves where that pin rest against it...now what?

 

[FloridaScaleBoater]

Fill in the grooves in the carb neck with JB weld for aluminum.
One that has cured, dress the neck with sand paper for a snug fit.
Once satisfied with the fit, scuff the circumfrance of the neck with sand paper. Disassemble the engine, then scuff the surface inside where the carb mounts. Clean both pieces with brake clean. Apply a thin layer of JB on carb neck, assemble and tighten pinch bar.
Let set overnight.
Replace bearings while you wait for it to cure.