4g kit with 5/8 shaft engine

GoldenMotor.com

agk

New Member
Oct 2, 2010
151
4
0
Santa Barbara CA
I've purchased a couple 4g kits from bicycle-engines.com and they were the tapered shaft engines. The clutches that came with these kits had an engagement rpm that worked fine. The last 4g kit they shipped me had the engine with the 5/8 shaft. The clutch in this kit wants to engage when I pull the recoil starter. I installed stiffer springs in the clutch because I had success doing this with these clutches in the past. Didn't work this time. I installed some shims with the stiffer springs and now I can start the engine without the clutch engaging, but it tries to engage at idle. I set the idle as low as it will go without stalling the engine and the clutch is on the border of engaging. Anyone else buy the 4g from bicycle-engines.com with the 5/8 shaft engine? I have one more 4g kit with the tapered shaft engine and I was thinking about putting it in this bike just so I can have a clutch that works properly.
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
38
Ridin' inSane Diego, CA.
I've purchased a couple 4g kits from bicycle-engines.com and they were the tapered shaft engines. The clutches that came with these kits had an engagement rpm that worked fine. The last 4g kit they shipped me had the engine with the 5/8 shaft. The clutch in this kit wants to engage when I pull the recoil starter. I installed stiffer springs in the clutch because I had success doing this with these clutches in the past. Didn't work this time. I installed some shims with the stiffer springs and now I can start the engine without the clutch engaging, but it tries to engage at idle. I set the idle as low as it will go without stalling the engine and the clutch is on the border of engaging. Anyone else buy the 4g from bicycle-engines.com with the 5/8 shaft engine? I have one more 4g kit with the tapered shaft engine and I was thinking about putting it in this bike just so I can have a clutch that works properly.
My only suggestion besides using the tapered shaft engine with the 3-shoe clutch on the 4G would be to get an EZM tranny for the straight shaft HS engine and sell the 4G tranny with the whimpy clutch. Or send it back in exchange for a tapered shaft HS (if they have any). Sorry to here this, good luck.
 

ocscully

New Member
Jan 6, 2008
373
1
0
Orange County, CA
agk,

The problem you are experiencing is two fold. The springs are part of the problem and the other area is the Bronze/Oilite Bushing. If you don't keep this bushing lubed it can cause enough drag to stall the motor at idle, or cause the bike to take off like a jackrabbit when starting. There is a USA made Oilite bushing that you can purchase from McMaster Carr that some members have had success using to replace the stock Chinese bushing. I've bought some of these but have not used them yet. I carry a small plastic bottle with a mixture of 30wt. motor oil and 20% Marvel Mystery Oil and add a drop to the bushing at the end of the crankshaft when it starts to drag. Link to replacement bushing McMaster-Carr Down at the bottom of the page Part# 6659K33 is the bushing that others have used and are claiming works much better than the stock one. Things to be aware of with this bushing is that it is not an exact size replacment. Though as I said above other members have reported success using them. They are very inexpensive to buy $1.39 each, so it hardly seems like you could go wrong giving them a try?

ocscully
 
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MotoMagz

Well-Known Member
Aug 2, 2010
1,817
1,154
113
Michigan
Mine has the new oilite bushing and clutch springs.Very low idle and no engine stalling.It's a very quit and smooth ride.
 

agk

New Member
Oct 2, 2010
151
4
0
Santa Barbara CA
Thanks for the input ocscully on the bushing. I did lubricate the bushing before installing it, but maybe it wasn't enough. I think we might take scotto's advice and just put an EZM unit on this bike. We've love riding our bikes that have the Q-Matic.
 

agk

New Member
Oct 2, 2010
151
4
0
Santa Barbara CA
agk,

Just curious? Do you have any affiliation with Affordable Go Karts there in Santa Barbara?

ocscully
That's me. If you are familiar with our website you will find some performance parts on there in the near future for the 49cc HS engine and the 79cc HF.
 

ocscully

New Member
Jan 6, 2008
373
1
0
Orange County, CA
That's me. If you are familiar with our website you will find some performance parts on there in the near future for the 49cc HS engine and the 79cc HF.
agk,

I purchased some parts from you many months ago. I bought one of your Air Filter Adapters, and one of your throttle linkage kits to use on my bikes. I look forward to seeing what parts you will be offering for these 4-stroke motors.

ocscully
 

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Felton

New Member
Dec 17, 2009
92
0
0
GA
I see you have a couple spots for MB's on your web site. I can't wait to see what you come up with.

Welcome to the forum
 

agk

New Member
Oct 2, 2010
151
4
0
Santa Barbara CA
I see you have a couple spots for MB's on your web site. I can't wait to see what you come up with.

Welcome to the forum
We will be focused on engine performance parts for the 49cc HS and the 79cc HF. It's a long process to develop parts, test them, tweak them, test again and put into production. We are working on it and having some fun at the same time. We'll post the new products on the forum as they become available.
 

Felton

New Member
Dec 17, 2009
92
0
0
GA
Now you really have me excited. I was hoping you were working with the 79cc hf. I am looking forward to adding an airfilter to my bike and maybe a carburetor.
 
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