Cheetah cub questions, domes, and timing

[Ducman]

My tax return was surprisingly larger than I expected this year thanks to a new baby and non working wife so I'm getting a set of cheetah cubs. I already have a +4mm stroke +5mm long rod motor with all the supporting intake mods. I'm going to get the 68mm bore +4mm long rod cub cylinders. I'm wondering how well the cub motor does on pump gas as far as low end power and what size domes to use for 91 oct pump gas at sea level. This shee is going to see 90% sand use but sometimes I like to take the sand trails with the wife too, where your not running WOT everywhere like in the open dunes.

 

I saw a site selling 24 cc BB domes for pump fuel and 20 cc BB domes for race fuel. Does this sound about right? What kind of timing do you run for cubs using 91 pump fuel, 100 octane race fuel, or 110 octane race fuel, and appropriate dome size/ timming for each fuel choise.

 

If there is a lot more low end available with smaller domes and 110 octane, its no big deal for me to get race fuel. But if its not going to make a real big torque difference to increase ridability on the sand trails and slower riding, I would like to run pump fuel to avoid the hastle. On week long trips to the OR dunes 20 gallons of race fuel tends to run out well before the week is up and I immagine fuel economy will go down pretty significantly with the cubs.

 

What kind of jetting changes will I need to make, I assume a lot larger mains but how much larger. Curently I run 310 mains in my TM 34mm Mikuni's. Would I be safe starting with say a 350 main? Anybody run cubs with TM 34 Mikuni's?

[Big Blue]

When you buy the cylinders just have the builder you bought them from cut the domes for your motor for you. All I have ever had mine on is race gas so I dont know about the difference in low end but it seems to lug around better than my 450 does.

[PassionRE]

My tax return was surprisingly larger than I expected this year thanks to a new baby and non working wife  so I'm getting a set of cheetah cubs.  I already have a +4mm stroke +5mm long rod motor with all the supporting intake mods.  I'm going to get the 68mm bore +4mm long rod cub cylinders.  I'm wondering how well the cub motor does on pump gas as far as low end power and what size domes to use for 91 oct pump gas at sea level.  This shee is going to see 90% sand use but sometimes I like to take the sand trails with the wife too, where your not running WOT everywhere like in the open dunes.

 

I saw a site selling 24 cc BB domes for pump fuel and 20 cc BB domes for race fuel.  Does this sound about right?  What kind of timing do you run for cubs using 91 pump fuel, 100 octane race fuel, or 110 octane race fuel, and appropriate dome size/ timming for each fuel choise.

 

  If there is a lot more low end available with smaller domes and 110 octane, its no big deal for me to get race fuel.  But if its not going to make a real big torque difference to increase ridability on the sand trails and slower riding, I would like to run pump fuel to avoid the hastle.  On week long trips to the OR dunes 20 gallons of race fuel tends to run out well before the week is up and I immagine fuel economy will go down pretty significantly with the cubs.

 

What kind of jetting changes will I need to make, I assume a lot larger mains but how much larger.  Curently I run 310 mains in my TM 34mm Mikuni's.  Would I be safe starting with say a 350 main?  Anybody run cubs with TM 34 Mikuni's?

473856[/snapback]

 

Ducman, its not just your cc's and timing you have to worry about, the squish clearance and squish band width must be matched to your cylinders at rated peak HP rpm in order for your squish velocity to fall into the right range. Re-cut off the shelf domes wont cut it...especially on hi-output designs on pump gas...Jim

[locogato11283]

iwould contact either your builder or dlnoss. im sure noss can answer your questions as he supplies a lot of domes for the cub motors..

[Ducman]

My builder is local and he's getting 109 HP out of his cub banshee and he has his own dyno to try different combos, he also cuts his own domes as well, so I have confidence that he can set it up. However, the cub motors he's built so far have just been designed for race fuel.

 

I just wanted some imput on how the cubs might run with lower compression on pump fuel and some idea of what dome sizes / timing / fuel combos people have tried and or reccomend.

[odaen]

Ducman, who's your builder near Redding?

[Ducman]

Ducman, who's your builder near Redding?

474455[/snapback]

 

The shop is called Looney Tooners. They haven't updated there site in a long time, it doesn't show all their products or services. Its right off I-5 in anderson near the outlets stores. Its a Father/Son business, Mike and Mick, very friendly.

http://ltpatv.com/

[odaen]

sweet, thanks, man. bet a good deal of their business is jet-ski's. was in Redding a couple of times this summer, and holy hell. I've never been anywhere where the wind was gusting like 20-30 and it was over 100 degrees. The breeze was definitely not refreshing. I'll bet the albino population is nil there, I swear I was looking for a red mofaka with a pitchfork....

[89Steeda]

I run my 4 mill on Super Unleaded. Patriot cut the domes.