I am building a clone GX200. I added a #90 jet, gx140 emulsion tube, high flow air filter, gx160 head, 18lb valve springs and a Honda gx160 flywheel (timing advance as well as bypassing the gov. All of this is going on a mb165 mini bike. I am waiting on a torque converter prior to running the bike. I am 250lbs, question is... with my weight and the torque converter, will my engine turn up to the point of the "danger zone"? I have read all of the threads about the warning of doing these mods without a billet connecting rod and flywheel. I usually hear about clone flywheels coming apart is why I chose to use the Honda. Also this is my first clone build up, can anyone tell me what to expect as far as power? rough hp. Any advise is welcome.
Will I reach "grenade" RPM?
- Thread starter Hillbilly Deluxe
- Start date
- Tags grenade reach rpm?
The springs are kind of a waste of money without a cam to support them. This will allow you to rev the engine up beyond what most consider the safe zone even for a Honda flywheel.
Above 6000 rpm there might be belt issues because of centrifugal forces but I don't know the opperating limits. So reving that high might cause slipping that gains you nothing.
If you keep the stock size tyre on the 165 with a 10 tooth TAV sprocket you will likely go a little faster than you want and not get all that that TAV offers. Look for a 9 or even 8 tooth for some improved torque. You have no front break, so speed is not your friend and a massaged clone on a 165 with a TAV can at full throttle drive right through that rear brake and burn it up.
Compression is your friend here, so is the timing and air flilter, but no mention of header. Look for something long as you can fit with modest diameter between 3/4 and 7/8.
As for power that combination might make between 8 and 9 Hp. That's plenty with the TAV and you will Realy feel it in the seat of your pants. The real advantage of where your going is the engine will be very well behaved and produce more power and torque everywhere not just in the top end. Wheelies are something your going to have to be careful of since its easy to pull the front wheel up just with the engine mods.
The governer can be modified to work within the RPM range of the TAV and give good performance so I would leave it alone.
All that is about as far as you can go with a stock rod and flywheel and still have a reliable engine that starts easily. I have been there and think thats a realy good start.
Also look into some mild head porting.
This is the point where most people should stop unless they are willing to invest in some racing parts and build a race engine. The TAV will not be much use with a more powerful engine because the belt was not designed for more than 10 hp ( it can do more but not without fast belt wear ).
Above 6000 rpm there might be belt issues because of centrifugal forces but I don't know the opperating limits. So reving that high might cause slipping that gains you nothing.
If you keep the stock size tyre on the 165 with a 10 tooth TAV sprocket you will likely go a little faster than you want and not get all that that TAV offers. Look for a 9 or even 8 tooth for some improved torque. You have no front break, so speed is not your friend and a massaged clone on a 165 with a TAV can at full throttle drive right through that rear brake and burn it up.
Compression is your friend here, so is the timing and air flilter, but no mention of header. Look for something long as you can fit with modest diameter between 3/4 and 7/8.
As for power that combination might make between 8 and 9 Hp. That's plenty with the TAV and you will Realy feel it in the seat of your pants. The real advantage of where your going is the engine will be very well behaved and produce more power and torque everywhere not just in the top end. Wheelies are something your going to have to be careful of since its easy to pull the front wheel up just with the engine mods.
The governer can be modified to work within the RPM range of the TAV and give good performance so I would leave it alone.
All that is about as far as you can go with a stock rod and flywheel and still have a reliable engine that starts easily. I have been there and think thats a realy good start.
Also look into some mild head porting.
This is the point where most people should stop unless they are willing to invest in some racing parts and build a race engine. The TAV will not be much use with a more powerful engine because the belt was not designed for more than 10 hp ( it can do more but not without fast belt wear ).
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Thanks for all of the input! I installed the springs because I thought I would get valve float at higher rpms... maybe I didn't need them, wasn't too expensive as long as there is no down side to them. I didn't mention exhaust, however I will end up building a header once the engine is fitted back on the bike. This is just a playing around toy for the neighborhood. I don't plan on anything too extreme, just a few hole shots to impress my neighbor with a stock mb165. I love building, just wanted to make sure I wasn't building a grenade. $200 bucks could get me a billet connecting rod, flat top and flywheel, but it has already gotten to be a pretty expensive toy for it's intended use. Thanks again!
Once you get into the flat top with the 14cc head pump gas won't cut it anymore.
At 11:1 and above you need to consider the cost VS gain. Now your looking at a cam and better carb to unlock the potential of the engine and thats more money. Then you need a good jack shaft, more money....
These run on money, money better spent on good tyres and a front brake if you ask me.
How old is the bike?
Front and rear bearing ar garbage, there are shimming issues you might need to look at as well to make sure the bearings are in the housing as far as they should be and the rear wheel is center and tracks correctly.
At 11:1 and above you need to consider the cost VS gain. Now your looking at a cam and better carb to unlock the potential of the engine and thats more money. Then you need a good jack shaft, more money....
These run on money, money better spent on good tyres and a front brake if you ask me.
How old is the bike?
Front and rear bearing ar garbage, there are shimming issues you might need to look at as well to make sure the bearings are in the housing as far as they should be and the rear wheel is center and tracks correctly.
I think the mods are going to stop were I am. The bike is a 2004. I have new brakes and bearings on order. Brakes were shot and bearings were a little rough... thought better safe than sorry. I have been looking at front breaks, not sure weather to use a rear wheel with a drum or find an add on disc... any advice?
I like the drum.
I used that and some odds and ends I found in dumpsters.
Use Snowmachine track bearings for the wheels and order Honda brake pads not the Baja stuff. Fill the void in the wheel hub 1/4 full with good quality grease ( yes this does little with sealed bearings but it keeps things rust free inside ).
Good close up of my early front brake conversion.
clone stuff :: 100_9780.jpg picture by Dougwp - Photobucket
Probably the best thing I ever did, best money ever spent colse secodn maybe the 14cc head and the governer modifications to get to 5000 rpm.
Everything after has returned less and less bang for bigger and bigger buck
I used that and some odds and ends I found in dumpsters.
Use Snowmachine track bearings for the wheels and order Honda brake pads not the Baja stuff. Fill the void in the wheel hub 1/4 full with good quality grease ( yes this does little with sealed bearings but it keeps things rust free inside ).
Good close up of my early front brake conversion.
clone stuff :: 100_9780.jpg picture by Dougwp - Photobucket
Probably the best thing I ever did, best money ever spent colse secodn maybe the 14cc head and the governer modifications to get to 5000 rpm.
Everything after has returned less and less bang for bigger and bigger buck