New Kyosho CRF
09-11-2007, 05:28 AM
#76
09-12-2007, 10:26 AM
#77
Tech Initiate
Kyosho CRF engine
I have read some of the threads on this motor. I'm in Northern California and just raced it for the first time. What I can say about this motor is it runs very smooth. It feels very responsive to the throttle. I wasn't the fastest guy that day but I figured out at the end of the day that my clutch was not up to par. However I finished in third for the day. Anyhow, the first problem that I had was firing it up for the first time. Those needles are in places where they probably shouldn't be. After getting the needles in the correct places, it fired right up and I ran 12 tanks with not one problem. I haven't experienced anything negative as of right now. I did notice that the bolt to hold the carb down is a bit small but my carb has not came loose. I'm not saying this is the best motor out and it has no problems but I can say that it is a monster motor for the price. At the end of the day the guy who won the race approached me and looked at my car and said he was gonna buy one these motors for his 720. If any of you guys have questions about this motor I will do my best to give you my honest opinion.
09-12-2007, 10:42 AM
#78
This has happened to a few people, including myself. Here is why:
http://www.rctech.net/forum/showthre...31#post3328931
The retaining doesn't work like it does on other engines. Once the glue cracks, trying to tighten the retaining screw so that the carb won't rotate will just strip the screw. I've done this twice already. First time because I thought the screw worked like other screws. Second time because I didn't know about the glue thing.
I haven't gotten around to fixing it again because I've been running the STI. Nano didn't say what specific glue to use, so I'm hoping JB Weld (slow cure) will do the trick. I'll probably get around to it next weekend.
BTW.. You have to cut off the insulator to get it off.
http://www.rctech.net/forum/showthre...31#post3328931
The retaining doesn't work like it does on other engines. Once the glue cracks, trying to tighten the retaining screw so that the carb won't rotate will just strip the screw. I've done this twice already. First time because I thought the screw worked like other screws. Second time because I didn't know about the glue thing.
I haven't gotten around to fixing it again because I've been running the STI. Nano didn't say what specific glue to use, so I'm hoping JB Weld (slow cure) will do the trick. I'll probably get around to it next weekend.
BTW.. You have to cut off the insulator to get it off.
What you can do is take out the "retaining pin". There is 2 pcs of "retaining pin" right, one with through hole, the other with 2mm thread.
File/Grind away 1mm from the inside on each side. By doing so, you allow the pin to have extra clearance to tighten the carb.
You will not have loose carb anymore...
09-12-2007, 01:30 PM
#79
I found that it is not the screw is not strong enough, just that the retaining pin does not have enough allowance to crimp on to the carb.
What you can do is take out the "retaining pin". There is 2 pcs of "retaining pin" right, one with through hole, the other with 2mm thread.
File/Grind away 1mm from the inside on each side. By doing so, you allow the pin to have extra clearance to tighten the carb.
You will not have loose carb anymore...
What you can do is take out the "retaining pin". There is 2 pcs of "retaining pin" right, one with through hole, the other with 2mm thread.
File/Grind away 1mm from the inside on each side. By doing so, you allow the pin to have extra clearance to tighten the carb.
You will not have loose carb anymore...
I'm not happy about the glue thing or the fact that I have to cut off the insulator. Once I JB weld that sucker, I hope I don't have to take it off.
I was looking at my original carb the other day and the insulator has a nice indentation from the retaining pin. Maybe that's why the orginal carb never moved.
09-12-2007, 01:38 PM
#80
X312T $233
09-12-2007, 04:51 PM
#81
That's a very interesting idea. I'm sure Fabrice had some reason for not designing it that way in the first place - like as to avoid the potential for creating an air leak.
I'm not happy about the glue thing or the fact that I have to cut off the insulator. Once I JB weld that sucker, I hope I don't have to take it off.
I was looking at my original carb the other day and the insulator has a nice indentation from the retaining pin. Maybe that's why the orginal carb never moved.
I'm not happy about the glue thing or the fact that I have to cut off the insulator. Once I JB weld that sucker, I hope I don't have to take it off.
I was looking at my original carb the other day and the insulator has a nice indentation from the retaining pin. Maybe that's why the orginal carb never moved.
Yes, I thought of it as well, but i think the insulator is soft enough to sit in where u tighten it without creating problems to leakage.
Maybe 2mm is too much, if you look at the original indentation, it is just enough to hold the insulator but no enough to hold the inner diameter of the carb.
So by shortening the retaining pin a little, it create just enough pressure through the insulator to hold the carb. as well.
09-13-2007, 02:27 AM
#82
I found that it is not the screw is not strong enough, just that the retaining pin does not have enough allowance to crimp on to the carb.
What you can do is take out the "retaining pin". There is 2 pcs of "retaining pin" right, one with through hole, the other with 2mm thread.
File/Grind away 1mm from the inside on each side. By doing so, you allow the pin to have extra clearance to tighten the carb.
You will not have loose carb anymore...
What you can do is take out the "retaining pin". There is 2 pcs of "retaining pin" right, one with through hole, the other with 2mm thread.
File/Grind away 1mm from the inside on each side. By doing so, you allow the pin to have extra clearance to tighten the carb.
You will not have loose carb anymore...
good tip, if my carby comes loose again, i will give one of the clamp sections a very small file down.
yeah to kyo-show, i agree the needles are way of from factory. mine was so lean it wouldn't start. had to re adjust top and bottom needles, but after that it was fine
09-16-2007, 01:43 AM
#83
ok i just had a race meet and the carby pritty much came loose again. i took it apart and realised that the plastic collet was loose. What is the best glue to use to stick a new collet on?? rndhawaii suggested JB weld, anthing else?
also, had anyone taped out the small screw hole that holds the carby clamps so that a 3mm screw can be used
also, had anyone taped out the small screw hole that holds the carby clamps so that a 3mm screw can be used
09-21-2007, 05:26 AM
#86
For the RRR, I highly recommend getting the CRF clutch parts. It will add another $40 to the cost of the engine, but it's really the only way you're going to get the most out of the engine.
Figure out where you're going to get your parts - Rear bearing (every 10 hours), plugs, carb insulator, carb retaining screw, etc. You can always get them from Team Orion, but that will cost you extra (as it does me).
With the CRF, if you blip the throttle and the idle doesn't come down right away, it's not tuned properly and you'll just have problems. This is probably the number one performance complaint with the engine. I always recommend the Bobby Watson method of tuning the idle/LSN - click here.
For all of it's innovations, the engine really doesn't run that much better or faster than any other fast engine IMO. In a RRR, it has plenty of bottom end for a small to medium sized technical track. In the hands of someone that can tune it properly, setup their chassis correctly and drive really well, it's pretty fast.
Like you said... looks pretty good and is relatively cheap.
Hope this helps.
09-22-2007, 12:53 AM
#87
I've had my share of good and bad days with the CRF engine, but once I figured out how to tune it properly, I have mostly good days.
For the RRR, I highly recommend getting the CRF clutch parts. It will add another $40 to the cost of the engine, but it's really the only way you're going to get the most out of the engine.
Figure out where you're going to get your parts - Rear bearing (every 10 hours), plugs, carb insulator, carb retaining screw, etc. You can always get them from Team Orion, but that will cost you extra (as it does me).
With the CRF, if you blip the throttle and the idle doesn't come down right away, it's not tuned properly and you'll just have problems. This is probably the number one performance complaint with the engine. I always recommend the Bobby Watson method of tuning the idle/LSN - click here.
For all of it's innovations, the engine really doesn't run that much better or faster than any other fast engine IMO. In a RRR, it has plenty of bottom end for a small to medium sized technical track. In the hands of someone that can tune it properly, setup their chassis correctly and drive really well, it's pretty fast.
Like you said... looks pretty good and is relatively cheap.
Hope this helps.
For the RRR, I highly recommend getting the CRF clutch parts. It will add another $40 to the cost of the engine, but it's really the only way you're going to get the most out of the engine.
Figure out where you're going to get your parts - Rear bearing (every 10 hours), plugs, carb insulator, carb retaining screw, etc. You can always get them from Team Orion, but that will cost you extra (as it does me).
With the CRF, if you blip the throttle and the idle doesn't come down right away, it's not tuned properly and you'll just have problems. This is probably the number one performance complaint with the engine. I always recommend the Bobby Watson method of tuning the idle/LSN - click here.
For all of it's innovations, the engine really doesn't run that much better or faster than any other fast engine IMO. In a RRR, it has plenty of bottom end for a small to medium sized technical track. In the hands of someone that can tune it properly, setup their chassis correctly and drive really well, it's pretty fast.
Like you said... looks pretty good and is relatively cheap.
Hope this helps.
i agree. John, i'd recommend straight up to cut the insulator and install a brand new one with JB weld. don't bother running it witht he standard glue on the seal, it will crack up and produce airleaks.
Ric B sells parts man and they are cheap. plugs $9, and he has all option parts/and standard parts. plugs are similar to an os 6, the fillament is thinner than a nova 6. i heard on this forum that nova 6 plugs also work with it.
www.bartzrcpartz.com.au
09-23-2007, 06:37 AM
#88
guys will i get a tighter and more secure fit of the carby clamps of i take out the o ring on the screw head, or will the screw vibrate loose if i take it out.
reason i ask is even after jb welding the new collet, i could twist the carby with my hand, meaning that, possibly it may come loose again. I noticed the CRF carby collet is a smooth plastic compared to the Ninja's roughish type look. maybe the smooth finish creates slip, and stops the clamps from biting into the collet, or the collet is too hard, hence not enough "bite" into the collet from the clamps
reason i ask is even after jb welding the new collet, i could twist the carby with my hand, meaning that, possibly it may come loose again. I noticed the CRF carby collet is a smooth plastic compared to the Ninja's roughish type look. maybe the smooth finish creates slip, and stops the clamps from biting into the collet, or the collet is too hard, hence not enough "bite" into the collet from the clamps
09-23-2007, 10:44 AM
#89
Before I glued the insulator, I lightly sanded the upper half of the carb above the ridge line to provide a better surface for the JB Weld, but didn't sand the upper half of the insulator just to see how well the JB weld would bond to it without sanding. You might want to try sanding both surfaces above the ridge line.
09-23-2007, 06:31 PM
#90
Before I glued the insulator, I lightly sanded the upper half of the carb above the ridge line to provide a better surface for the JB Weld, but didn't sand the upper half of the insulator just to see how well the JB weld would bond to it without sanding. You might want to try sanding both surfaces above the ridge line.
woops too late, i glued it ages ago, lol it should be fine...i hope
