CY26cc vs 30.5cc Rovan 4bolt +2mm

[nuclemike]

Hi mates, I had a worn out CY 26cc and decided to install the Rovan 4bolt 30.5cc +2mm upgrade kit. Myself, My brother and my dad have the Dominator pipe on our HPI Bajas. The strange thing is that their CY26 is pulling wheelies and seems to have more power, and my 30.5 seems to be underpowered at the launching stage, and not revving as high. There seems to be some short juicy power only at the mid revs. We all have the WT668B, same gearing, same tires, same fuel, same dominator and same 8k clutch. Their launching is hard and sounds aggressive. Mine launches underpowered and opens up in the mid revs, but still not faster then theirs.

The engine is on 2nd tank ...I have no leaks, good compression, white spark, new NGK plug.

Do you have any ideas what this could be? I am frustrated! I pretend to have more power due to the larger bore and longer stroke! Thanks in Advance

I would really appreciate if you hint me up!

 

[CALIC]

As its still on its second tank, the engine still new and needs breaking in. I have a OBR 30.5 full mod and it started to come to life after 4-5 tanks. I have always followed obr instructions on my engines and never had a problem. Heres a vid explaining the basics on breaking in:

http://www.oneillbrothers.com/blog/breakin/

Hope this helps and good luck!

 

[nuclemike]

Thanks for the answer. I hope that it will loosen up. The tuning is right. Plug's got a tan color. But it feels exactly like a turbo lag at launching. If you keep the engine in mid revs the power is quite ok. So CALIC... You had this launching problem as well on your obr? Even with the right needle settings?

 

[CALIC]

I only had this problem on my first 1-1.5 tanks. Try this: copied from ddm

If your engine bogs out when transitioning from low speed:
The high jet is too far closed. Open the jet by turning it counterclockwise until you are at least 1 1/2 turns open, and then gradually close the jet until performance is as desired. Poor engine compression, blocked exhausts, and very heavy engine loading can all also cause bogging.

 

[nuclemike]

Thanks for your help. I will try richening the HSN. I was also considering swapping to a wt990. I heard some people say that it will remove the launching lag.

 

[rcwildman]

Yes, 990 is the way to go, I have them on all my cars, those carbs are very nice, and take the lag away.

 

[Johan]

My kM 4-bolt is slow on revving regardless of load and mine's on the 10th or so tank. Got a new 990, Dominator v2 silenced, Turtle v2 HD clutch, lightened flywheel, stock gearing and a lightened Zenoah clutch. My HSN is set just below 1 turn which is far from the 1 1/2 standard setting. If I turn the HSN closer to 1 1/2 it makes the classic bogging sound.

The HPI 26cc motor my pal has in his 5T rips and leave me in a cloud of dust.

 

[nuclemike]

I guess ill be heading for an obr longblock full mod then. I cannot stand a 26cc being better than a 30.5! Thanks guys!