HF 6.5 (200cc) motor on a bike?
- Thread starter oldtimer54
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oldtimer54
Member
Seems you are using this crank: 3pc Wide Crank Pedal Kit [4S-CDS-3pcCRANK] - $29.99 do I need anything else to switch over to this new wide crank as I seen no bearings with this kit and as you know this bike comes with a one pc crank so do I need anything to mod this bike to take the 3 pc crank set? I couldnt wait to buy the forks so I bought these: SR Suntour XCM 26" Black 1" Threadless does anyone have any input on these forks? Thanks for thelp guys!
Yes you will need the 1pc to 3pc conversion kit. Use the conversion kit along with the wide crank kit and you'll have what you need.
Those forks are the same ones we have used. That's a great price they have too! For an inexpensive suspension fork they are not bad. They have warnings telling you they are not for jumping etc and indicate they are only for lite street use. We've used the forks on a few bikes and they do a good job of absorbing the bumps at 30+mph. We remove the stickers and they look pretty nice on our black bikes. A 160mm rotor is the largest that can be used with these forks.
Here's the last bike we built for a customer using those forks.
http://i126.photobucket.com/albums/p109/agk409/DSC_0067.jpg
http://i126.photobucket.com/albums/p109/agk409/DSC_0070.jpg
http://i126.photobucket.com/albums/p109/agk409/DSC_0067.jpg
http://i126.photobucket.com/albums/p109/agk409/DSC_0070.jpg
oldtimer54
Member
Well Ive been trying to order your part number AGK700 and it seems to be back ordered? Is there any other header that would fit this bike / motor combo?
AGK700 will not work as it exits in front of the engine which would have it pointing at your engine plate. We make AGK700 for the paramotor guys that put one of these engines on their back with a prop and fly around with a parasail.
I don't really like the fit of the headers we have in inventory for a bicycle application. I make a header using our CNC flange and some bent tubing. This allows me to route the exhaust toward the front of the engine and have it exit toward the ground. I just use the 1" OD bent tubing we have in 90 degree and candy cane bends. I cut where needed and slip fit with a piece of 1 1/8" OD tubing. Then I twist and turn the slip fit pieces into a position that I like and weld it up.
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MikeJ
New Member
Hey Oldtimer54 -
Check out a few pictures at:
Honda GX-160 Extra Long Mike - MotoredBikes.com: Motorized Bicycle Forum .
They are photos of my bike. You can see what I did to get the intake and exhaust plumbing out of the way of the riders' legs. The steel exhaust parts are 100% AGK, just cut up by me and welded locally to my specifications.
MikeJ
Check out a few pictures at:
Honda GX-160 Extra Long Mike - MotoredBikes.com: Motorized Bicycle Forum .
They are photos of my bike. You can see what I did to get the intake and exhaust plumbing out of the way of the riders' legs. The steel exhaust parts are 100% AGK, just cut up by me and welded locally to my specifications.
MikeJ
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oldtimer54
Member
We have an account with a bicycle parts supplier which is where we get the forks. I can get a set of the threaded forks for you if you want.
If you still have the threadless forks you may want to consider converting to threadless. You will need a 1" threadless headset and a 1" stem. Your local bike shop should be able to help you with those parts. The threadless system looks much cleaner, it's a little easier to put together and it's probably stronger.
If you already sent your forks back and want my help getting a threaded set, just give me a call.
oldtimer54
Member
oldtimer54
Member
ok have every thing built and started it up to day. First problem is the idle is to hi so the wheel spins with the cvt. When I try to rev the motor it bogs hard. The motor is getting super hot not warming up and the plug seems to be white. I have the mikuni 22mm carb with stock jet. There seems to be no idle set screw on this carb just air gas. I have it set to stock 2 turns. Iam at around 8000 feet. Ill try to ajust the needle but seems like a rejet will be needed. I realy need help guys any advice would be great.
culvercityclassic
Well-Known Member
Hey Old-timer...I had the same issue and a couple friends I had over found the problem. The throttle cable was a little too short which was keeping the slide open on the carb; we ended up cutting some of the cable housing off which made the cable longer. We used a dremel tool to carefully complete this. I have also posted a picture to show you the screw for the idle adjustment.
About the motor heating up: do you have the shroud on this motor or does it look like the one in the picture? All I can say is it gets hot real fast of not moving with air over it.
I would also order some more jets or read the post on the AGK site about jetting the carb. Its cheaper to drill them out then to buy a bunch.
If you can post some pictures it would also help.
Let me know if you need to chat...
CCC
About the motor heating up: do you have the shroud on this motor or does it look like the one in the picture? All I can say is it gets hot real fast of not moving with air over it.
I would also order some more jets or read the post on the AGK site about jetting the carb. Its cheaper to drill them out then to buy a bunch.
If you can post some pictures it would also help.
Let me know if you need to chat...
CCC
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oldtimer54
Member
Thanks ccc I was afraid I would have to do that. I nolonger can drill jets kind of on the move right now. I have three builds I have to store and none are working right. Was hoping to get this build going today need it for transpo. So for 8000 feet I wonder what jet to use? I cant aford a bunch of jets at this moment. I have the shroud installed. Today my muffler started to glow bright red thought it was going to turn white hot? I can post pics tomorrow. Also the thing is vibrating so bad in the time it took to warm the engine up the bottom bracket loosened up and the set screwes on my jack shaft fell out?
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oldtimer54
Member
oldtimer54
Member
If your exhaust is glowing red you are definitely running that engine lean. Check your spark plug, it will be white. No surprise with the stock main jet, but difficult for me to give you a good recommendation due to your high elevation. Your Mikuni probably has about a #95 main jet from the factory. We usually run about a #125 main jet with your engine combination at sea level. So you may want to try about a #105 main jet. Like CCC said it's cheaper to drill jets.
If you are getting a lot of vibration on the initial clutch engagement you can run a lower gear ratio to help clear that up. Just go to a larger rear sprocket. These engines are not very well balanced so they do vibrate more than expected. Bryan told me he can hardly hold the handlebars at the end of a straight when the engine is turning 8500 rpm due to the vibration. When the balance shop balances the engines they say the engines are pretty far out of balance. They charge about $150 to balance the rotating assembly.
I might be getting a little carried away here. Let me know if there is anything I can help you with.
If you are getting a lot of vibration on the initial clutch engagement you can run a lower gear ratio to help clear that up. Just go to a larger rear sprocket. These engines are not very well balanced so they do vibrate more than expected. Bryan told me he can hardly hold the handlebars at the end of a straight when the engine is turning 8500 rpm due to the vibration. When the balance shop balances the engines they say the engines are pretty far out of balance. They charge about $150 to balance the rotating assembly.
I might be getting a little carried away here. Let me know if there is anything I can help you with.
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oldtimer54
Member
sportscarpat
Bonneville Bomber the Salt Flat record breaker
AGK,
With vibration being an issue would you recommend just going ahead and balancing the engine? Who do you use for this service? Jeff, how is the vibration on your engine? Problem? I would guess some engines stock are balanced better than others. I hate vibration on bikes.
With vibration being an issue would you recommend just going ahead and balancing the engine? Who do you use for this service? Jeff, how is the vibration on your engine? Problem? I would guess some engines stock are balanced better than others. I hate vibration on bikes.
I would start by pulling the spark plug out and confirming its white (lean condition). You said the exhaust was glowing red so that tells me the engine is lean. But just pull the plug so you can see what it looks like before you start changing jet sizes.
Ideally I would use a numbered drill bit set to drill the stock jet rather than guess on what size jet(s) to buy. If your spark plug is white you will need a larger main jet. So take the numbered drill bits and find out which drill bit matches the size of the stock jet. So pull the main jet out and put the drill bits in there until you find the drill bit that fits perfectly. Grab the next larger size drill bit and drill out the main jet. Install the main jet, start the engine and ride your bike. While riding bring it up to wide open throttle (the main jet is responsible for fuel delivery from about half throttle to wide open throttle). Ride your bike for about five minutes with several wide open throttle passes. Kill the engine without letting it idle for too long and check the plug again.
Repeat this process until you get the proper golden tan color on the spark plug. Don't be tempted to skip drill bit sizes as you drill your main jet as you may drill it too large. It's tedious to drill one size at a time, but this is how you'll get it dialed in to the correct size. Once you have a good plug reading you can always buy a couple main jets that are close to the size you drilled your stock jet to. This will allow you to try one size above and one size below to see what you like the best.
Installing a 12.5 pilot jet is real common with the 22mm Mikuni too. The pilot jet handles fuel delivery from about idle up to about half throttle. So if you notice a bog or hesitation in this throttle range with the stock 15 pilot jet, the 12.5 pilot jet will clear that up.
Here's our drilling main jets page for reference.
AGK - How To Drill the Main Jets - Affordable Go Karts
Here's the tuning manual for the Mikuni carb.
AGK - Carburetor Tuning - Affordable Go Karts
There are two vibration issues we've had to deal with. The first is vibration upon clutch engagement. When we open the throttle from a dead stop and accelerate without pedaling, we would get an annoying vibration as the clutch is engaging. Once the clutch is fully engaged the vibration is gone.
There are a couple ways of dealing with this. You can pedal to get the bike moving which greatly reduces the vibration felt upon clutch engagement. You could modify the clutch to engage at a higher rpm. A typical MaxTorque clutch engages at about 1800 rpm. Changing the spring and/or shoes so the clutch will engage at a higher rpm will reduce the amount of vibration felt. And changing to a lower gear ratio greatly reduces the amount of vibration.
One of our 79cc bikes is geared 12.44:1 and the clutch is setup to engage at about 2400 rpm. The vibration upon clutch engagement is not bad and there is no vibration in the higher rpm range. This bike will climb very steep hills and it will do over 30mph.
The other vibration issue we've experienced is with the highly modified 6.5hp engine on one of our race bikes. This bike has a final gear ratio of 13.43:1. We do not experience the vibration when clutch engages on this bike like we do on the 79cc bike. This is due to the gear ratio and stall speed we are using on the clutch. However we do experience a lot of vibration in the higher rpm range. These engines vibrate. They are out of balance. Some are worse than others. The tolerances on these clone engines vary greatly sometimes so one engine will vibrate more than the other and one will outperform the other due to the varying tolerances.
We have customers who have taken their rotating assembly to a machine shop to have them balanced. This will eliminate much of the vibration the engines produce. The more mild engines don't vibrate as much and probably will not be an issue. I have a bike with a stock 6.5hp engine and the vibration is no problem. I have a couple engines producing about 15hp and they do vibrate.
Sorry for the long winded reply. There is a lot of information to share. Anyone can call me or email me to talk about these engines more.