BGF Hongdu/Solex

[cannonball2]

my main jet isn't off center, but i have no way to determine the size. i'm confused about what exactly the parts from steve's are...if i order a jet from steve's, am i getting a quality jet or just another chinese jet that may or may not be right? i want a genuine solex jet.

I think Steves is selling Chinese based stuff, however I think it is from the upgraded engine. The piston I keep referring to is not whats in our engine, so that stuff is different and probably better quality.

I corresponded with Jeff Mathews of Velocruze, the parts he sells are European in origin. You might try a jet from him if you feel you need one. At this point I am going to use the jet that came with my #2 engine.

 

[cannonball2]

Waynez, the original solex rings are cut at an angle at their gaps to help seal them, the Hds are straight. There is no reason to have the gaps aligned, set em like you said. Have you checked the gaps?

That flat at the top of the piston ports is supposed to improve low end. It was a mod that could be done to the original piston, mentioned in BrianSolexes mod page.

 

[wayne z]

I'm sorta dissapointed. This engine runs exactly like the last one. Ran it for 2 hrs, no change.
And the compression test, with a different guage, is 75 lbs hot, just like engine #1

Have any of you checked compression? I'd love to know what the other engines from BGF are getting.

I think the same mechanic assembled both. The rings are fitted exactly the same. The ends near the gap have been polished down and rounded, so much, that the last 1/4" near the gaps don't contact the bore. I think this is the problem. Theoreticly a 1/2" ring gap The ring gap itself is good, bout .003 or .004 just eyeballing

I have some new rings coming from Steve's. Hope they're HD and not Solex. My jets are about the same. One is slightly off ctr and the other is not. Could tell no difference in them running
in the engine.
I saw the Video C-ball made, My 2 engines won't run like that at all. Barely make 10mph.

 

[cannonball2]

Wayne z, I placed a large order on Monday from Steves for the bike parts of my Velosolex. I got a conformation email, but have received no notice of shipment, have you recieved anything?
I cant imagine what is up with your engines, surely 2 wouldnt have issues. Did you ever consider what I wrote about the head and base gaskets?

 

[wayne z]

I placed an order with Steve Last saturday, nothing here yet.

What post was that 'bout the gaskets?

I re-used the copper clad base gasket with some anerobic sealer used for gasketless cases
I made a new head gasket from 1/32" Garlock gasket material,, similar thickness as thr 2 stock gaskets. 'Swat I had on hand.

Engine # 2 has the same exhaust mods as yours, and the intake holes of the airbox drilled to 8 mm. Was still 4 stroking a lot, so I installed jet from #1 and it runs and idles way better than #1.' Seems like the geometry of the jets is critical.
#2 jet had a small burr around it's orfice, so I ever so slightly chamfered the hole, and after that the 4 stroking was Much worse.That's when I installed jet from #1 an noticed increased performance compared to #1.
I spent a while riding in my grass lawn tonight. tryin to seat these rings. the grass is a good constant resistance to keep some load on the rings.

Thinkin about tryin something radical like feeding it a little powdered cleanser, or running it with no oil a bit, to try to wear the rings enough that they touch the bore at the gaps.
Maybe a rough hone job?

 

[cannonball2]

I posted way back that my #2 engine is like yours with the thicker copper base gasket and 2 paper head gaskets. #1(the vid engine) had only a thin paper gasket on the base and head. I dont know what you have now, but as received the effective length of the cylinder has been increased with the gaskets reducing the compression.

 

[wayne z]

Hey C-ball, is one of your engines still open? If so, take a real close look at the ring ends and please describe what you see.

Has anyone else inspected their rings. I am curious to see how the ring ends are finished on other HD's, 'specialy the good running ones.

.The custom rings guy in Texas is starting to sound like a good option. Have them pinned too.

I love a challenge, to keep me sharp. This is one :~)

 

[cannonball2]

I will have a look at the rings on #2 its is still apart. Im with you on the challenge, these little motors are just cool, I want to figure em out too.

 

[wayne z]

I posted way back that my #2 engine is like yours with the thicker copper base gasket and 2 paper head gaskets. #1(the vid engine) had only a thin paper gasket on the base and head. I dont know what you have now, but as received the effective length of the cylinder has been increased with the gaskets reducing the compression.

my #1 engine has theoriginal undisturbed thin head gasket.
My #2 had the 2 gaskets. replaced with similar thickness graphite gasket.
#2 runs best now, with jet from #1 .

Gonna drive it around in the pastures tomorrow, keep it loaded good, and try to burn it in or burn it out LOL

 

[cannonball2]

Hey Wayne, #2 seem to have some of the same characteristics of your engine. The lower two rings are polished on the tips of the gaps while the upper ring has an unworn area on one side of the gap. I would think that the lower rings have been hitting the port maybe, and the upper ring might be a cylinder issue. look carefully at the top of the cylinder.

 

[wayne z]

Hey Wayne, #2 seem to have some of the same characteristics of your engine. The lower two rings are polished on the tips of the gaps while the upper ring has an unworn area on one side of the gap. I would think that the lower rings have been hitting the port maybe, and the upper ring might be a cylinder issue. look carefully at the top of the cylinder.

top of my bore looks fine. I don't think the rings are rounded from catching the ports. I think the installer did that.

Ran my #2 engine several hours today. It has started running pretty good, Im sure it's over 15 mph now.

Started having issues with trash(rust from tank) in the carb and filter.
got to where I had to blow everything out bout every 20 munites, when it clogged up too much to run with the choke.

Hafta clean the tank better.

I finaly quit when I noticed the pivot bolt behind the manifold has backed all the way out, against the manifold.

Does anybody know what thread had the guy from Texas that makes custom rings to fit any piston? He can pin them too if needed
Were the original Solex rings pinned?

 

[cannonball2]

This thread is where I mentioned Frank Bowman. I have bought his rings in the past, they are about the best there is, I dont thing they need to be pinned,as the originals were not. His service has always been quick. He will custom make and fit the rings if you send him the piston. His rings are designed to run almost no gap and the compression increase over a set of good rings is noticeable

 

[cannonball2]

BTW the Solex gap placement is top and bottom rings @6 oclock, middle@11 oclock, with 6 oclock being the front of the engine.

 

[camlifter]

after riding mine a few times it started running really poorly. wouldn't rev out and very hard to start. took most of it apart, every thing look good, cleaned the carb although it wasn't dirty. put it back together and it still ran bad.
i took the jet out of my solex and put it in the hongdu and now it runs great, better than ever, put the hongdu jet it the solex and it now barely runs, the jet is clean but looking at the 2 i can see that the hungdu jet is bigger. going to solder it up and redrill it smaller untill i get it running right.
kind of weird because it run fine the first few times i rode it. if your having trouble with low power and not reving up look at the jet. the main jet is the one on the back of the carb next to the throttle.

 

[cannonball2]

All right! Now we may be getting somewhere. The stock 28cc jet is .48mm, you might want to start there. Off to mic some jets!

 

[cannonball2]

Makes sense as the "stiffer" un-broken in engine probably needed the richer mixture to run, as it loosened the fuel became excessive.

 

[camlifter]

my micro drill set came up missing so i just ordered a new set, be a few days before i get it. for now it's running really good with the solex jet in it.
also my clutch started working. must need some break in time to free it up.

 

[cannonball2]

Yeah you really have to force it to idle/slip by holding the bike and applying throttle. Once it breaks loose it get better everytime you stop. When I replaced the jet in mine it was a different beast.

 

[Colony Five]

i thought it was the other way around, that the jet was too lean. i suppose it could be either/or. bottom line is that the chinese jets must be junk. although so far mine is still running with no issues.

 

[camlifter]

normally when an engine is to lean it will bog with the throttle open, get the big waaa waaa sound and no power, when to rich it just blubbers and won't rev up.

when everone with the ht motors talk about 4 stroking whats happening is there motors are running to rich and the motors just blubbering and won't rev out all the way. ( by the way theres no such thing as 4 stroking in a 2 stroke, if it was firing every fourth stroke it would be missing on ever other firing stroke. and if it was firing on the wasted spark it would be single stroking. 4 stroking is just an uninformed term for running to rich)