Well, after fighting and fighting one of my LRP 28S3's, I finally called it quits and ordered a new engine. History of that is here: https://www.rcnitrotalk.com/forum/threads/alternate-carb-for-a-lrp-28-s3.85277/
New engines always look nice when you open the box and this one was no different. Cooling head has an extra fin over the 28 and the crank case is considerably re-enforced with gussets and extra material.
As with any new engine, the first thing I do is take it all apart to inspect for loose shavings, proper assembly and sealing with RTV. When removing the head, I nearly broke my 3mm wrench as the bolts were so tight that they popped when they broke loose. Every one of them. I was affraid that the first thing that would happen before I even ran it was a bolt would snap off in the block. Luckily, they all came loose. Upon removing the starter housing, I don't know what I did as I'm usually pretty careful to avoid unwinding the recoil spring, but as soon as I released the last screw, BOING! Snarled mess. I moved that to the side to rewind later. Then when I went to remove the backplate screws, two of them weren't even finger tight.
Then I took the plate off and inspected the internals. One of the cleanest engines I've ever bought. I ran a cotton swab around inside all the recesses I could reach and removed only a very small amount of aluminum dust. After a few drops of ARO on the bearings, OWB, conrod, wrist pin and sleeve I procceded to RTV up the carb and backplate.
Before sealing the carb, I took a couple photo's of it next to the 28's carb. The carb neck is about 1mm larger in diameter:
The venturi is pretty similar:
The carb itself is a bit more bulky than the 28's. Not sure why. The HSN/LSN were way off. Per the book, HSN should be 2.75 turns and LSN should be 2.25. They were 4.5 and 3.5 respectively. I set them to 3.25 and 2.75. Figured a hair more rich would be best. The HSN recommended setting seems pretty lean to me anyway, but time will tell.
One thing I did notice was that the sleeve on the exhaust port for the 30 hangs down about 1.5mm further than the crank case is:
The 28 exhaust port is flush with the case:
Hopefully that's how it's supposed to be.
I rewound the recoil spring and put that back together then installed the flywheel/shoes/bearings/cb from the 28. Sticking with 17/49 gearing for now as that was a pretty good fit for the 28 when it ran somewhat ok.
Not sure when I'll start break-in. Temps around here don't look like they are going to get above 60 the rest of the week/weekend. If ti does get to 60 and doesn't rain... I might throw a hand warmer or two around the head and get started on it anyway.
Here's to hoping I didn't just get another aggravating engine!
New engines always look nice when you open the box and this one was no different. Cooling head has an extra fin over the 28 and the crank case is considerably re-enforced with gussets and extra material.
As with any new engine, the first thing I do is take it all apart to inspect for loose shavings, proper assembly and sealing with RTV. When removing the head, I nearly broke my 3mm wrench as the bolts were so tight that they popped when they broke loose. Every one of them. I was affraid that the first thing that would happen before I even ran it was a bolt would snap off in the block. Luckily, they all came loose. Upon removing the starter housing, I don't know what I did as I'm usually pretty careful to avoid unwinding the recoil spring, but as soon as I released the last screw, BOING! Snarled mess. I moved that to the side to rewind later. Then when I went to remove the backplate screws, two of them weren't even finger tight.
Then I took the plate off and inspected the internals. One of the cleanest engines I've ever bought. I ran a cotton swab around inside all the recesses I could reach and removed only a very small amount of aluminum dust. After a few drops of ARO on the bearings, OWB, conrod, wrist pin and sleeve I procceded to RTV up the carb and backplate.
Before sealing the carb, I took a couple photo's of it next to the 28's carb. The carb neck is about 1mm larger in diameter:
The venturi is pretty similar:
The carb itself is a bit more bulky than the 28's. Not sure why. The HSN/LSN were way off. Per the book, HSN should be 2.75 turns and LSN should be 2.25. They were 4.5 and 3.5 respectively. I set them to 3.25 and 2.75. Figured a hair more rich would be best. The HSN recommended setting seems pretty lean to me anyway, but time will tell.
One thing I did notice was that the sleeve on the exhaust port for the 30 hangs down about 1.5mm further than the crank case is:
The 28 exhaust port is flush with the case:
Hopefully that's how it's supposed to be.
I rewound the recoil spring and put that back together then installed the flywheel/shoes/bearings/cb from the 28. Sticking with 17/49 gearing for now as that was a pretty good fit for the 28 when it ran somewhat ok.
Not sure when I'll start break-in. Temps around here don't look like they are going to get above 60 the rest of the week/weekend. If ti does get to 60 and doesn't rain... I might throw a hand warmer or two around the head and get started on it anyway.
Here's to hoping I didn't just get another aggravating engine!
