Fuel for OPS .21 3.5cc

[Jim Zelazny jr]

Ok...here I think are part numbers for this engine.So looks like that Ebay rod matches #352 which is what I need ? Sorry for all these posts...did not expect all the new issues,but I want it done and right.

 

[Terry Keeley]

Not sure where you got that parts list but I scanned my 30+ year old OPS catalog for you.

That rod might fit but it's not the right part number for your engine, looks like you need a 3521 for your 8770 motor.

 

[Jim Zelazny jr]

Interesting that both manuals are a bit different which makes this harder.
I will attach this manual and sure looks like the same engine as well.
Jim

 

[Terry Keeley]

That's an older catalog than mine, they added the 4th digit to the part #'s, mostly zeros.

In any case you want a 352 or a 3521. A 351 or 3510 would probably work too. The 3524 you posted would be a crap shoot I'd say.

Again, I'd post a WTB in the for sale section, you'll probably get what you're after. Or if you can find an RPM (aftermarket) rod even better. It's bushed top and bottom.

Not sure if this is still in stock but it's worth a shot: http://jethobby.com/_shop/product/product_detail.php?id=18414

 

[Jim Zelazny jr]

I am confused,bought the #3524 just in case I never find anything and those are gone.
Worse come to worse,I can resell it I suppose.
This has become challenging.
Here is manuals from OPS - https://www.mantuamodel.co.uk/products/ops-engines/spare-parts

 

[Terry Keeley]

Here's an old FleeBay listing saying a 35241 is the same thing so your's might just fit. At least it's bushed on both ends.

https://www.ebay.com/itm/VINTAGE-OPS-ENGINE-CONNECTING-ROD-3521-OP35241-352-3-5cc-SPEED-SPA-OLD-STOCK-NOS-/370782210729?hash=item5654578aa9&pt=LH_DefaultDomain_0&nma=true&si=NgfX%2FTH1XwxROQIbDI%2BxF1BJqSs%3D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

 

[Jim Zelazny jr]

What if this Ebay part works or fits in this engine? Basically,will it self destruct if it this is not the right part? If so,how can I know or will it just not fit in properly right off ? Sorry to sound dumb,but regarding this RC boat,I am very dumb You will not hurt my feelings telling me bad news or that I just wasted money...I wasted more money sitting on a bar stool years ago ...haha.

 

[Jim Zelazny jr]

I missed your last post,but we shall see when it arrives.I have a serious impatient way about me and like to spend money fast and get the job done...but also I can be my own worst enemy in that regard.But I am actually having fun with this and have not put it in the water yet! I am also that guy that will ruin some poor guys day of fishing when this thing is ready

 

[Jim Zelazny jr]

I sent a message to the Ebay seller and his exact reply -
"Thank you for your purchase, glad to see you are trying to keep that engine running. The "352" is the primary part # and OPS added these numerical additions, 3, 4, etc. depending on the country these were sold in --- so I am told and was able to decipher after a lot of research".
I think the best he can do on this part number stuff and looks about what I came up with.Lets see what happens here.

 

[Terry Keeley]

If it fits it'll probably work, I doubt they changed the C to C length over the years. The bottom end might be too beefy and not fit in the case but you might be able to massage it.

ps: the only way throwing money at this will fix it is if you buy a whole new motor! You're gonna need some patience to get this 30 yr old piece back to good health...

 

[Jim Zelazny jr]

For now,I have a lot to work on...will post results when I get all this stuff in front of me to assemble...then go from there.I am very grateful for all the input.It is all we can do at this point.I think all will work out soon.

 

[Jim Zelazny jr]

Received a reply from Mantua and asked about the #3524 con rod I just bought.This is what they had to say...so looks I just need to install it and check clearances...fingers crossed.I am guessing they mean it obviously should not touch the crank case when rotated? Or could it still be the wrong rod when turned by hand but not @ high RPM`s ? What should I look for basically ? Mantua reply - 3524 is a later version stronger conrod with 2 bushes. There can be clearance issues with the inside of the crankcase on engines made pre1998 as later ones were machined with more clearance.

 

[Jim Zelazny jr]

Bearings already came in mail just now.Will do this when I am alone and have focus.
Also,local hobby shop may have the bolts after all -
http://www.danscraftsandthings.com/istar.asp?a=3&dept=23&class=2
I need to check this place out...new to me -
http://www.performance-hobbies.com/

 

[Terry Keeley]

https://www.dubro.com/products/socket-head-cap-screws-metric

Rochester MBC is a great club in your area:

https://www.facebook.com/groups/1457148284550459/

 

[Jim Zelazny jr]

Looking now and joined the page.Calendar is empty for 2019 and Events are 1 year old.I can not seem to find where they are located.I heard there was one in Macedon,NY,but that is a good haul away.

 

[Jim Zelazny jr]

Ok...here I go again.
Looking at the new bearings both sides look exactly the same to me.
Do I need to remove a cover or seal ?

 

[Terry Keeley]

Ok...here I go again.
Looking at the new bearings both sides look exactly the same to me.
Do I need to remove a cover or seal ?

If they have covers or shields you should remove them, you can leave the outside one on the front (small) bearing if you want.

A sharp pick works, start between the inner race and the shield.

 

[Jim Zelazny jr]

So one side has no shield and the other does for the inside bearing? I see the non covered side looking in to my engine now,so assume to do same for new.But to verify...other than cover,either side will work or do they go only one way.Looks like each side has no difference until I remove one cover.

 

[Jim Zelazny jr]

I removed the shield from one side of the larger bearing.The small bearing has both shields on it.
Videos I am watching show the small bearing installed with shields on both sides and the large bearing has one shield and the open end is against the crank.I just removed both bearings on this engine and went easier than expected.Neither of these original bearings have shields on them at all ? Does this mean I must do same with the new? I will not drop the new ones in yet until someone lets me know.

 

[Jim Zelazny jr]

I see that these are just covers and still allow oil to get inside the bearings.II already removed one cover from the large bearing,so will leave that alone.Looks like leaving both on small bearing is fine.Some are saying RPM`s may be sacrificed...I think maybe if your competing and will utilize all you can get.Just like 50% fuel vs 15%...for me,not gonna make a lot of difference since there are no trophies waiting for me