Gasbike.net Grubee GT5 w/high compression head issue

Matts22366

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What's up guys, I just bought a GT5 pro kit and it came with a high compression head, and I was reading "Jaguars" posts on some mods that must be done to prevent det. What are those mods? Also what are some mods that should be done first CDI, exhaust, carb????

thank u much,
 
Whatever kit you bought from gasbike was not made by Grubee.

Grubee has not shipped any kits to the USA for a long time and
they do not have a business relationship with gasbike.
 
Whatever kit you bought from gasbike was not made by Grubee.

Grubee has not shipped any kits to the USA for a long time and
they do not have a business relationship with gasbike.
Absolutely correct.
Gasbike hasn't had any real Skyhawk anything for a couple of years, they just continue to use the name, just like they still call their EPA illegal 66cc engines 80's.

Don't get me wrong here...
I don't want to see gasbike go away as they import hundreds of things I often need, but the new actually good quality stuff from the YaunDong (Skyhawk) factory are headed to the US now and beside a couple of vendors like bicycle-engines.com I am working towards being a supplier of good cool stuff I like myself.

I know, way off topic, but what the heck, relevant 1st hand facts ya know?
I generally wouldn't even dip my toe into in a lake of uncertainty but I am weighing my options for authorized parts supply with actual real support as I kinda do that now for free, but everyone has to eat ;-}
 
Ok well my question was an I going to have a problem with the high performace head will it damage my motor, should I buy a new CDI ???
 
yes, with high compression you need the Jaguar CDI because its retarded timing matches the higher compression.
get a gauge and make sure the cranking psi is not more than 135psi.
 
yes, with high compression you need the Jaguar CDI because its retarded timing matches the higher compression.get a gauge and make sure the cranking psi is not more than 135psi.
I understand ase what about those product, does it have switches for different retard/advance settings? Also are u familiar with the kit I got, it's the GT5 kit from www.kingsmotorbikes.com, and it comes with a high comp head http://www.kingsmotorbikes.com/product_51_detailed.html So my question remains what CDI should I buy, your jag that's $75 or do I have another choice as far as a performace CDI goes? Also what other MODS should I do first to obtain optimum performace for example, different carb, jetting, exhaust...... What should be first?
 

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keep in mind, jaguar makes the jaguar CDI and is trying to sell his product. his CDI is certainly a good product that will improve engine life, but running a different CDI such as the HD Lightning or Rocket CDI or even the stock unit isn't going to kill your engine. there are plenty of racers using the stock CDI with compression figures exceeding 170 PSI. of course, they're killing bearings and rings much faster than most people, and the cylinder plating only needs to last a few miles.
 
Just a note about the gasbike GT5 engines, they are not real GT5's.

Grube Skyhawk GT5 engines are made in the Yuan Dong engine factory and gasbike can't buy them.
Like their fake GT2 gastank frames, they are just using the good name.
 
I noticed some of you are ill informed as far as what grube does with those warehouses full of years past models meant for US shores that could not get shipped here due to ever changing EPA regulations . they find loopholes , list them as " off road use only" and leave off the ID plate , they then wholesale these older grubees to companies here with an agreement that they NOT sell them under the official grube name , for example : Fastbikemotors.com sells the grubees with 38 mm stroke , long rod , type b piston , exaust ports are 40mm , but the intakes are 32 mm, also bicycle Motor Works sells them too , the guy that runs kings and gasbike got in trouble years ago with grubee for selling older , non tagged motors under the grubee name
 
I understand ase what about those product, does it have switches for different retard/advance settings? Also are u familiar with the kit I got, it's the GT5 kit from www.kingsmotorbikes.com, and it comes with a high comp head http://www.kingsmotorbikes.com/product_51_detailed.html So my question remains what CDI should I buy, your jag that's $75 or do I have another choice as far as a performace CDI goes? Also what other MODS should I do first to obtain optimum performace for example, different carb, jetting, exhaust...... What should be first?
First off neither of the heads you are showing are high compression heads. The gt 6 head with the converging fins is a 6cc head. The same as a stock slant plug head. The gt5 round head is a 8 cc head and requires cyl. decking to maintain stock compression. Mzmiami's latest round head is 6cc, but the earlier ones were 8cc so who knows what the latest ones from gasbike are. Don't believe what you read. CC the heads yourself before making any assumptions or modifications to the cylinder. About the only way you will know for sure what head you will get is to order American made like a Fred head/Cr machine.
 
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