BGF Hongdu/Solex

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camlifter

camlifter

Active Member
May 4, 2009
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acme labs marion ohio
mine quit running on me too. looks like the lower cyl gasket is blown. haven't had time to mess with it yet. it trys to start and smoke puffs out under the cyl. there oil down there too. shouldn't be to hard to fix but i hoped it would last longer than this before it needed repair.
 
cannonball2

cannonball2

Well-Known Member
Oct 28, 2010
3,682
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Colonial Coast USA.
camlifter said:
mine quit running on me too. looks like the lower cyl gasket is blown. haven't had time to mess with it yet. it trys to start and smoke puffs out under the cyl. there oil down there too. shouldn't be to hard to fix but i hoped it would last longer than this before it needed repair.
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The Chinese gaskets are junk and they seem to put em on in any order or #. I got a hold of some OE Solex for mine, the are totally different and much better quality. They are the atandard grey gasket material and you only use one top and bottom, not 1 or 2 or 3....
 
cannonball2

cannonball2

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Oct 28, 2010
3,682
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Colonial Coast USA.
Yeah, the copper really looks like it ought to have been a head gasket and the blue head gaskets the base. I dont remember if the copper has the hole for the compression release. All these gaskets lower the compression for what ever reason.
 
cannonball2

cannonball2

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Oct 28, 2010
3,682
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Colonial Coast USA.
There is a special puller to remove it. I have removed my using the old method of holding the engine up by the flywheel and giving the crank a sharp rap with an alloy hammer, takes a bit of skill not to damage the crank. Im am sure you have seen there is a nut and a cover then the actual flywheel nut. If you use the above method be careful!
 
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Adam F

New Member
Apr 24, 2010
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Brunswick, Victoria
After making a very simple flywheel puller (a thick piece of alloy and three bolts that attach to the flywheel holes) dad and i stripped down the motor to find the problem. The nut that holds on the clutch mechanism had worked itself loose allowing the clutch to spin on the shaft. Fortunately no damage done. We retightened it with some loctite. The nut is a strange size and the only spanner that fits is a British standard size!

I filled the tank, mixed up some spare fuel and set out for a ride. I managed to go around 20k's before the nut worked loose again! Guess the loctite hadn't set properly.
Luckily it was flat and by that stage I was only 2.5k's from home. We will have to pull it down again today and get the nut tighter and preferably with a tab washer or something.

Here is a short clip of my completed build. Apart from the clutch problem I am really happy with the bike. It is nice and quiet and rides well. I found out yesterday that a head wind will really slow this down. I figure i was only doing around 15 k's ( 10 mi) when I was riding alongside a river with a head wind. Still very good local transport.

‪Beach cruiser with hongdu velosolex‬‏ - YouTube
 
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u2seek42

u2seek42

New Member
Aug 1, 2010
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US
Hi all,
about to buy one of these buggers. Made the mistake of buying one of the 66cc chain drive kits. A nightmare! It was clearly made to fit no bike made on this planet.

This looks like a better way for me to go.

Thanks to all, the wealth of info here is staggering.

To think that we once were fearful of the Chinese, if their guns and bombs are made as well as their other crapola, what was there to fear?

Sounds like to me, that it would be best to tear it all down and rebuild it right.

The fellow in Canada has these for $188.00 with 49.99 shipping
the 3 pack of them with shipping works out to be $211 each.
 
cannonball2

cannonball2

Well-Known Member
Oct 28, 2010
3,682
223
63
Colonial Coast USA.
Each one is an unkown, they all seem a bit different. But they are fairly easy to work on and original Solex parts generally fit, some times if only in the right groupings. Once straightened out, they run well and should be very durable if they are like their Solex counterparts. They are a pretty cool little FD that atleast has a little style to it.
 
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Adam F

New Member
Apr 24, 2010
12
0
0
Brunswick, Victoria
The nut that retains my clutch keeps undoing! Last time I put it together we cleaned the shaft and nut with loctite primer and set it with a loctite semi perm goo. I let it cure for the recommended 24 hour period and then rode the bike. After 3ks it let go again.

Anyone else have this problem?

Adam
 
cannonball2

cannonball2

Well-Known Member
Oct 28, 2010
3,682
223
63
Colonial Coast USA.
So far you are the only one to mention it. May sound like a dumb question but are you torquing it down really well, like with a socket. Its a real odd size nut. If you are using a wrench it might not be getting tightened enough.
 
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Adam F

New Member
Apr 24, 2010
12
0
0
Brunswick, Victoria
cannonball2 said:
So far you are the only one to mention it. May sound like a dumb question but are you torquing it down really well, like with a socket. Its a real odd size nut. If you are using a wrench it might not be getting tightened enough.
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Thanks for the reply Cannon.

No, that is a reasonable question! It took us a while but we have finally found an offset ring spanner ring spanner that fits and are using it. It is difficult to stop the shaft rotating but with one person gripping it and the other tightening it seems really tight?

I have read on the s3800 pages that the Nut on the "other side" of the clutch needs to be spaced out 1mm rather than being snug. Will try that next and see if it helps!
 
camlifter

camlifter

Active Member
May 4, 2009
1,033
16
36
acme labs marion ohio
replaced the gaskets on mine and it still won't run. got spark, compresion and fuel. it ran fine then just died and will not start anymore. trys to start and back fires. iv'e had the top end and carb off, everything looks good. going to check the fuel pump next even though it is getting fuel, thinking the back fires may have damaged the diaphragm. i can say for sure i won't be buying another one.
 
Al.Fisherman

Al.Fisherman

New Member
Sep 9, 2009
1,963
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0
Calera, Alabama
camlifter said:
replaced the gaskets on mine and it still won't run. got spark, compresion and fuel. it ran fine then just died and will not start anymore. trys to start and back fires. iv'e had the top end and carb off, everything looks good. going to check the fuel pump next even though it is getting fuel, thinking the back fires may have damaged the diaphragm. i can say for sure i won't be buying another one.
Click to expand...
Never had one much less worked on one, but the backfire leads me to believe that the engine is not in time. Maybe a woodruff key broke somewhere?? I'm leaning on getting one.
 
wayne z

wayne z

Active Member
Dec 5, 2010
1,743
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38
louisiana
Check the fuel filter.and the jet for debris. the filter isn't that reliable, larger chunks can get by. I have to clean trash from the rusty tank outta my jet occasionly, when it starts to run bad.

Can you see fuel in the return line when trying to start?

The fuel pump on one of mine quit once. I dismanteled it some and found a small metal burr in one of the check valves. I didn't remove the check valve, just blew the burr out using a pick and compressed air. Works fine now.
 
cannonball2

cannonball2

Well-Known Member
Oct 28, 2010
3,682
223
63
Colonial Coast USA.
Check the screws/gasket in the crankcase(side) cover, if they have loosened you will lose the compression for the fuel charge. Maybe it has something to do with the blown base gasket. The crank key is cast into the flywheel, they dont seem problematic, who knows though.
 
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