Fuel for OPS .21 3.5cc

Intlwaters

Help Support Intlwaters:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

I have recently puchased an entire boat/radio at a lawn sale.What fuel can be used?

  • Question

    Votes: 0 0.0%
  • Answer

    Votes: 0 0.0%

  • Total voters
    0
Well...so much on finding past history on this boat.It is endless sea of details.
But I will sum it up...the boat we all agreed was already setup to run as is.That is where it left off on this thread and other groups I joined.After a run through,greasing of shaft,new glow,new bearings and using the X440 was determined to be started and set for lean on the bench.Then take it out and test in water.The video is that very first test and like Terry mentioned...too rich.I will need to just get back to the pond and set it up a bit leaner and keep testing until she runs full throttle clean but not too lean.Since the last bench test and tune...it appears it changed.Soon as I get it ready taking it back and running it.Will post new results when that happens.What I do not understand is everyone says it will lean out in the water...it did the opposite.
Jim
 
The pipe looks very long with no pressure fitting, new looking.

What OPS plug is it? Any I've ever seen are super cold. You want something hot like a K&B 1L, HP, McCoy 59 or O'Donnell 277.
 
Last edited:
An OPS guy called me from Texas and we talked for over an hour about the boat in great detail.He has TONS of nitro and OPS and said he retired from them some time ago and sent me props,glow plugs and the carb for free.I am looking at the glow plug he sent and said it should work.McCoy MC-9 ? He sent 2 new in pack and one I dropped in.Same pipe...forgot what it was determine to be in regard to brand.This boat is almost identical to how I got it except going through maintenance,engine bearings and replacement carb.I think it comes down to another run and tune.
Jim
 
MC-9 shud be OK, not ideal but it shud run.

Check the pipe length when you get a chance. Is there a pressure fitting on it?
 
Pressure fitting?
There is a rubber like fitting on the engine port and the metal pipe slips into that with clamp.
Here are measurements...is this right ?
11.jpg
 
Pressure fitting?
There is a rubber like fitting on the engine port and the metal pipe slips into that with clamp.
Here are measurements...is this right ?
View attachment 275358

As I thought, that pipe is new and wayyyy too long.

You can add probably 2" from the glow plug to the start of your lines and maybe another 2" from the end of the yellow line to the start of the converging (tail) cone or weld. So your pipe length the way it's normally measured is about 13". Fast guys will run that pipe around 8" but if you cut it to about 9" for now it will get you going, right now it's just acting like a big restrictive muffler and not supercharging at all.

Again. Take a string and measure from the glow plug along the center of the pipe to the weld. What is that measurement?

There should be a small fitting in the pipe (usually in the middle of the large straight part) with a fuel line that runs back to the tank, this pressurizes the tank and helps to feed fuel to the motor. Looks like you need one. Your LHS shud have something.

https://www.amazon.com/9051-Degree-Thin-Pressure-Fitting/dp/B0006O92SG

https://stumpfabrication.com/collec.../products/pipe-pressure-port-bulkhead-fitting

JB weld would work good to pu the water p/u back on the rudder.

Also the strut looks deep, you'll want the stuffing tube right up against the bottom of the V. You got a pick showing how deep it is?
 
Hmmmm...I am pretty confused at this point.I was told 1000 things and even here on this forum.Did many things and this was never mentioned once.This is the same pipe when I got it...old as heck not new.Nothing is new on this boat except the bearings.
Not sure but you helped me out 3 months ago when I bought it on my first posts.This is the exact same setup it was when I bought it and posted to 3 groups since.So I am confused about this pipe thing now.No one mentioned it until now.One of my other group are telling me it is the 15% fuel I am using...something else we already talked about before and was not a problem then.I have not made any changes to this boat except the bearings,con rod,cleanup and lubrication and swapping that crappy plastic Perry carb with the old better one.
 
Last edited:
Yes...there is a pressure line on exhaust to fuel tank for pressure.
I think what happened is our previous conversation was lost and we are starting all over again way off target :) I do not expect anyone to re-read all the posts previous to this point...but we went down all this a long time ago.I am going to stick to the original plan from where we left off.
 
Re-read my post Glasshopper.

Not to "blow my own horn" but I have been racing nitro R/C boats for 40+ years and flew model airplanes before that. I lost count but IIRC I have 5 or 6 National Champion trophies in this very class.

If you want any more help you'll have to work with me...
 
Last edited:
Terry,
I know you are experienced...this is not the question at all.
I started this thread WAY back when I first got the boat for a mere 15 bucks.Other than everyone telling me replacing the bearings are a must,I went and did just that.During that procedure the con rod was found to be beat.So ordered and replaced that but had to modify it to work.We also all discussed 15% Omega fuel will work,just not a good as 50% which is only a difference for guys that race and are really into it.So that was ruled out as ok to use for now.Then the ongoing issue with that Perry carb...if you recall the neck was worn too badly and would not tighten.After a long long search a guy sent me one,some props,glow plugs and was an old OPS guy with lots of stuff left around.We talked for an hour by phone and he gave me detailed info about what I have,what I need,how to and what not to do.After all this,the parts he sent arrived and I was only awaiting a good carb. I had all other things cleaned up,oiled and ready to run.In this thread we talked about the exact same things and it ended where I needed to find a place to test run it.I had a lot going on here as a family member was sick and passed away.This was most of my summer and until now was able to get the boat to a pond for the test run that was put off for 3 months or close.What confuses me is we never talked about the pipe or anything else in this entire thread since the beginning...what happened to ready to test run it in the water? Now that video sucks and does not have the part where it was started for the first time,how it ran or the launch.This was the first time this boat was ran and tossed into water...once.I have not tried any other tuneups yet and think I better do that before jumping into other issues or possibilities.I do not think this boat was built by a rookie.From what others have said,whoever owned it did a great job...so to think it has wrong parts on it sounds way off to me.What I think we have is a very old boat and engine that sat for 20-25 years or whatever and needed to be cleaned up and freshened up using only obvious things.You asked about the fuel pressure and exhaust...we are way past all that from previous conversations.I understand you can not recall all we have done here on this forum on this project...but thinking we went off sibject a bit.In my opinion,the engine sounded like it flooded out to me and I jusy need to try again and was looking for someone who can aid me in tuneup starting points.I think you were correct...I need to lean it and mess with the carb setup more and spend a day at the pond.So until then...I will get back here and post hopefully another video of a strong running boat :) I do appreciate the help in these groups,but since I waited so long to return to this group with progress...we are going backwards and not where we left off earlier several posts back before the airboat run.
Jim
 
Terry,
I know you are experienced...this is not the question at all.
I started this thread WAY back when I first got the boat for a mere 15 bucks.Other than everyone telling me replacing the bearings are a must,I went and did just that.During that procedure the con rod was found to be beat.So ordered and replaced that but had to modify it to work.We also all discussed 15% Omega fuel will work,just not a good as 50% which is only a difference for guys that race and are really into it.So that was ruled out as ok to use for now.Then the ongoing issue with that Perry carb...if you recall the neck was worn too badly and would not tighten.After a long long search a guy sent me one,some props,glow plugs and was an old OPS guy with lots of stuff left around.We talked for an hour by phone and he gave me detailed info about what I have,what I need,how to and what not to do.After all this,the parts he sent arrived and I was only awaiting a good carb. I had all other things cleaned up,oiled and ready to run.In this thread we talked about the exact same things and it ended where I needed to find a place to test run it.I had a lot going on here as a family member was sick and passed away.This was most of my summer and until now was able to get the boat to a pond for the test run that was put off for 3 months or close.What confuses me is we never talked about the pipe or anything else in this entire thread since the beginning...what happened to ready to test run it in the water? Now that video sucks and does not have the part where it was started for the first time,how it ran or the launch.This was the first time this boat was ran and tossed into water...once.I have not tried any other tuneups yet and think I better do that before jumping into other issues or possibilities.I do not think this boat was built by a rookie.From what others have said,whoever owned it did a great job...so to think it has wrong parts on it sounds way off to me.What I think we have is a very old boat and engine that sat for 20-25 years or whatever and needed to be cleaned up and freshened up using only obvious things.You asked about the fuel pressure and exhaust...we are way past all that from previous conversations.I understand you can not recall all we have done here on this forum on this project...but thinking we went off sibject a bit.In my opinion,the engine sounded like it flooded out to me and I jusy need to try again and was looking for someone who can aid me in tuneup starting points.I think you were correct...I need to lean it and mess with the carb setup more and spend a day at the pond.So until then...I will get back here and post hopefully another video of a strong running boat :) I do appreciate the help in these groups,but since I waited so long to return to this group with progress...we are going backwards and not where we left off earlier several posts back before the airboat run.
Jim

Well I see you like to talk WAY more than you like to listen so I wish you luck with it.

Sometimes I wonder why I bother really...
 
Last edited:
Somehow we got off topic and we are reinventing the wheel on this boat...somewhere I need to find a point where I realize it is impossible to convey information using text.I laid out this boat best I could starting on post #1...how we got to the pipe being too long I don`t know.I was not looking for help when I posted the video of the boat bogging out.I was finishing the post with the first test that lasted about 2 minutes and was wondering what anyone thought as to why it bogged out...I sort of get combustion engines and was either lean or rich.Since I could clearly see fuel pouring out all over from the port,this said to myself...gee...that`s a lot of fuel dumping in there and it runs like crap.Let me reduce this fuel flow.
So I closed the fuel off a bit more and it ran better..still rich but better as I was told numerous times that your supposed to run rich and it will lean out once under load...but in my opinion,it was still too rich.I cant make you go back to refresh you memory from the start of this thread...and do not expect you to.But how did we get to this pipe thing? Basically asking why was this not mentioned 3 months ago ?...Today is a pipe...next month what else will I need for this 15 dollar boat turning into a $1000.00 boat ? I truly appreciate your comments...but do you not see what I mean here? We are WAY OFF the rez.
Jim
 
Well I see you like to talk WAY more than you like to listen so I wish you luck with it.
And if I took what every boat guy told me in the 3 groups I joined...would need to take out a home equity loan on my home to get this boat running :(
Nothing wrong with this boat...just needs time at the pond and tuning.
Jim
 
Terry,
this is not my intentions to argue or tell you who is right or wrong.You know more about this stuff than I do for sure and that is why I came to this forum to get expert advice.
But let be honest about all this.I posted my boat purchase and deal and everyone said it was a nice well built boat.Whoever built it did a good job and obviously knew something.Maybe not compared to today`s standards,but for the time very good build and setup.THAT I learned already.
I was told many things that should be replaced,and were obvious.We talked about fuels but 15% was said will be fine for a newbie until I learn how to setup the mix...then go higher like 30-50% someday...providing I want to squeeze out speed although not mandatory in this case.
Without rewriting the entire details of all that was suggested and done already 3 months ago,I went back to read the beginning and ask myself one question...why has no one mentioned the pipe length? There is even a discussion trying to guess what brand it is.All I know is of all 3 groups I joined,I used the best reasonable info without wasting money on stuff I am not interested in doing like RACING and squeaking out every millisecond as I just want it to run its best as is.It was hard enough to ask about this OPS engine to find no one knew where to get parts for it.Thankfully I found 2 obscure people never mentioned in any of the 3 group myself.It was not easy and was sort of the most important part of joining these groups.AND TO BE FAIR...I did all the things people suggested within reason and to get the basics only right to where it was time to run it.I shared the video to see if anyone could tell me if it sounded lean or rich.Sunday I am going to try again and keep trying until I find the right setup on the carb.I am not interested in revisiting what I already discussed since post #1...we are way past that and is not time to test and tune it even if I have to spend a gallon of fuel and take all day.No offense and still going to say thank you for all your help to this point and I have no hard feelings.We just got off target somehow and I will blame time on that.This is an old project and post so I cant expect anyone to remember the process we already been through.
Jim
 
Dave...was never looking for miracle,just wanted to get the 15 dollar boat running as it was built the best it can run.Not looking or interested in clubs ,racing or trophies .Just some fun is all . I think I did well not breaking the bank and have no plans in doing so.Time consumed is more valuable than money to me but like to stay with basics here.I am grateful to all on this project for the help and tips...please hear that !!
Just a bit frustrated to do all the previous things when it seems to me all it needs is needle adjustments.I`ll figure it out.The gentlemen that sent me all the OPS parts for free contacted me and is walking me through setups to work on next time at the pond.He is an OPS guy and ran them for years.If I get it running the best it can be...will post it again here for a happier ending :)
Jim
 
I feel bad for that OPS Guy as I'm sure at some point in the next week you will know more than him . Everyone that commented on your "thread " has been down this road before many times years ago . The collective knowledge of members of this site is staggering and you would be hard pressed too find anyone , anywhere that has done more with these engines and setups .
Soon you will blow your first connecting rod and wonder why but it truly does just happen . So be kind to the guys that have given up their time and advice to help you along the way . I have nothing to add as I have only been running boats for 39 years so what could I know . Good luck and enjoy the boat .
 
No dude...DO NOT talk to me that way.You have no idea who your talking to but I know EVERY forum I EVER joined is to expect arrogant,know it all,Ego maniacs.It is part of the forum society.I had patience through this entire project.Came here to ask for some help,not some over thought,racing nuts opinions and fanatical little details.This is a toy,not a job or a life.I paid 15 bucks and got an old cool vintage boat that is perfectly fine for what it is!! You DO NOT talk down to me,You do not tell me how I am or should be.I despise control freaks ! I could have never asked anything here without someone having the need to always be the TOP DOG of all things...that is expected on these sites.This boat is nothing to me,just a toy so lets get that straight.I do not make a life of it wasting life away to take a toy around in a circle.You know as well as I do that your out of line to make me out as the a-hole.You know NOTHING about me or who I am so do not even play this with me ! You all know I came for simple help...I got NO help to be quite honest right after the bearing change part way back on this forum.Yes...it was the wise thing to do and the rest was basics...but here we are and myself defending what anyone that can read all the posts from the beginning can clearly see.I asked for OPS engine parts and guess what...NO ONE here had a clue and any and all info for parts lead to a dead end...so NO...you guys do not know as much as you think you do ! If only you knew what others have told me exact opposite of what YOU tell me here ! It is almost hilarious but I know to weed out logical from ridiculous thankfully. If you did,you would have sold or directed me to a reliable source and you FAILED !! I get it with people like this...find a guy that needs help,and show off your expertise to make yourself feel good...which is sad if THIS is what you do all day.Here is what really happened here...I took a 3 month break from this project and you guys took NO TIME to review and refresh your memory from the earlier things already done and needed or the direction this has already been and gone.You do not remember anything you already told me about fuel (15%) props and more.Now suddenly it is a whole new batch of goofy things wrong with it? You kidding me? Saying the pipe is the wrong length is STUPID and you know it.This boat was built and run just as good as any pof you could have done it for the time but somehow it does not meet your specs.Stop kidding yourselves and everyone else...you know **** well this boat was good as is and only needed some simple things to get it running...FACT ! Your WRONG otherwise...a word that kills you. I have never been so insulted as I am now with a group of people. No one in this group knows crap about OPS or where to get parts...period.Nor do you know how to run them.And the guy that DID help me took the time to call me long disatnce and we talked for over and hour.I stood over the boat and described everything about it and sent images just like I did here.And NOT ONCE did he find anything what you guys told me here was wrong.He said the boat will run great just like I have it and sent me a carb and other things FOR FREE worth over 100 bucks HIS COST !! That is real help and he explained in detail what I never got here about tuning.If it blows up...who cares.If I listen to people here I will have spent 1000 bucks on it.This is a joke...now go ahead and tell the moderator to delete this post...and I will share this this with other boat groups so they can see how people here really are.You should be embarrassed,but arrogant pompous people do not have those feelings.Go find another victim to feed your egos.
And for the record...thing you SHOULD NOT say when helping people said already by 2 of you in one day.Everyone knows what that means -
1- "I have nothing to add as I have only been running boats for 39 years so what could I know"
2 -
Not to "blow my own horn" but I have been racing nitro R/C boats for 40+ years and flew model airplanes before that. I lost count but IIRC I have 5 or 6 National Champion trophies in this very class.

If you want any more help you'll have to work with me...
But yet...neither led me to a place to get parts for the OPS !!! :)
 
Last edited:
Back
Top