RB Concept Engine Thread..
#1561
#1563
first post and new to the forum but not new to RC's, and well to make a long story shot i have a RB C12 that was bench-top broken in by myself and then is sat for years and now im back into it and am having problem with it running.
just put a new RB plug in it, and as soon as i take off the glow plug starter, it dies, leave it on and it runs. i do remember that when i was breaking it in i didnt have to leave the pluge hooked up. also what should my starting settings be on the carb.?
please take it easy on me. (still relearning all the RC terms) when i went to get the rest of the missing parts for the rest of the RC i found out how much has changed since i lasted ran RC's.
Have the HPI MT Racer and the C12
THanks
just put a new RB plug in it, and as soon as i take off the glow plug starter, it dies, leave it on and it runs. i do remember that when i was breaking it in i didnt have to leave the pluge hooked up. also what should my starting settings be on the carb.?
please take it easy on me. (still relearning all the RC terms) when i went to get the rest of the missing parts for the rest of the RC i found out how much has changed since i lasted ran RC's.
Have the HPI MT Racer and the C12
THanks

#1564
#1565
#1567
Chris I have a weird one for you..
Well, here is an interesting issue.
I have rebuilt 2 engines.
One, and Axe Rossi and the other is a RB WS7.
Both are doing something they didn't do before.
Both when reaching about 180-190 degrees will idle high.
AFter blipping on the throttle, it might come down after 5-10 seconds
If I rev the engine high, it will stay kind high for some time. 20 seconds maybe
Temps are around 230 when running on a tight track.
The engine didn't do this when I was breaking it in.
I have done the following:
replace all fuel lines.
sealed both carbs.
sealed both back plates.
seal adjustment nut to hold the carb on the block.
lubed the o-rings on the carb with silicone. (lite coating)
both have had front bearings replaced.
Nothing works.
Fuel tank doesn't leak.
Fuel tank seal looks like it's in good condition.
Tank doesn't leak when turning upside down.
Any idea what it might be??
Orings in the carb maybe??
Well, here is an interesting issue.
I have rebuilt 2 engines.

One, and Axe Rossi and the other is a RB WS7.

Both are doing something they didn't do before.
Both when reaching about 180-190 degrees will idle high.
AFter blipping on the throttle, it might come down after 5-10 seconds
If I rev the engine high, it will stay kind high for some time. 20 seconds maybe
Temps are around 230 when running on a tight track.
The engine didn't do this when I was breaking it in.
I have done the following:

replace all fuel lines.
sealed both carbs.
sealed both back plates.
seal adjustment nut to hold the carb on the block.
lubed the o-rings on the carb with silicone. (lite coating)
both have had front bearings replaced.
Nothing works.
Fuel tank doesn't leak.
Fuel tank seal looks like it's in good condition.
Tank doesn't leak when turning upside down.
Any idea what it might be??

Orings in the carb maybe??
#1568
Tech Regular
iTrader: (9)
Joined: May 2010
Posts: 389
Chris I have a weird one for you..
Well, here is an interesting issue.
I have rebuilt 2 engines.
One, and Axe Rossi and the other is a RB WS7.
Both are doing something they didn't do before.
Both when reaching about 180-190 degrees will idle high.
AFter blipping on the throttle, it might come down after 5-10 seconds
If I rev the engine high, it will stay kind high for some time. 20 seconds maybe
Temps are around 230 when running on a tight track.
The engine didn't do this when I was breaking it in.
I have done the following:
replace all fuel lines.
sealed both carbs.
sealed both back plates.
seal adjustment nut to hold the carb on the block.
lubed the o-rings on the carb with silicone. (lite coating)
both have had front bearings replaced.
Nothing works.
Fuel tank doesn't leak.
Fuel tank seal looks like it's in good condition.
Tank doesn't leak when turning upside down.
Any idea what it might be??
Orings in the carb maybe??
Well, here is an interesting issue.
I have rebuilt 2 engines.

One, and Axe Rossi and the other is a RB WS7.

Both are doing something they didn't do before.
Both when reaching about 180-190 degrees will idle high.
AFter blipping on the throttle, it might come down after 5-10 seconds
If I rev the engine high, it will stay kind high for some time. 20 seconds maybe
Temps are around 230 when running on a tight track.
The engine didn't do this when I was breaking it in.
I have done the following:

replace all fuel lines.
sealed both carbs.
sealed both back plates.
seal adjustment nut to hold the carb on the block.
lubed the o-rings on the carb with silicone. (lite coating)
both have had front bearings replaced.
Nothing works.
Fuel tank doesn't leak.
Fuel tank seal looks like it's in good condition.
Tank doesn't leak when turning upside down.
Any idea what it might be??

Orings in the carb maybe??

#1569
If it is doing it on two engines that sounds like something in the fuel or exhaust system to me. Are you using the same header and pipe on the two engines? If so I have had issues like that when there was a tiny crack in the header. Could also be the rubber exhaust gaskets. Do you happen to see any air bubbles in the fuel line?
#1570
first post and new to the forum but not new to RC's, and well to make a long story shot i have a RB C12 that was bench-top broken in by myself and then is sat for years and now im back into it and am having problem with it running.
just put a new RB plug in it, and as soon as i take off the glow plug starter, it dies, leave it on and it runs. i do remember that when i was breaking it in i didnt have to leave the pluge hooked up. also what should my starting settings be on the carb.?
please take it easy on me. (still relearning all the RC terms) when i went to get the rest of the missing parts for the rest of the RC i found out how much has changed since i lasted ran RC's.
Have the HPI MT Racer and the C12
THanks

just put a new RB plug in it, and as soon as i take off the glow plug starter, it dies, leave it on and it runs. i do remember that when i was breaking it in i didnt have to leave the pluge hooked up. also what should my starting settings be on the carb.?
please take it easy on me. (still relearning all the RC terms) when i went to get the rest of the missing parts for the rest of the RC i found out how much has changed since i lasted ran RC's.
Have the HPI MT Racer and the C12
THanks


#1573
Hi. Can the lack of a good gasket be an issue??
I don't think my gaskets are in bad shape. Fairly new, but,
what if the seal was not good. I was just thinking of possible issues that
might cause a leak.
I don't think my gaskets are in bad shape. Fairly new, but,
what if the seal was not good. I was just thinking of possible issues that
might cause a leak.
#1575
It's possible they are both just out of tune as well. If your rich on the LSN your idle gap is most likely open too far which can cause the high rev followed by dropping down. I would suggest on the RB that you open the throttle ALL the way and hold it open, close the LSN and then back it out 5 turns. Close the HSN and back it out 3.5 turns. Now pull off the air filter and remove the venturi from the carb and set your idle gap so that it's open about the thickness of a credit card (between .6 - .9 mm) This will probably be rich and will want to load up and die so lean the LSN till it will idle good. Now tune the HSN till it runs well up top. You may need to make some more small adjustments to the LSN and possibly the idle but they should be small adjustments.



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