Re: Suzuki fa50 low top speed need help, tried everything.

> Pushrod Fifty Wrote:

> -------------------------------------------------------

> If you didn't block the oil inject system youre pulling air into the

> crankcase. That foam is upholstery closed cell foam. Best to put

> everything back to stock and work with one variable at a time.

This is a golden rule with 40 year old antiques.

Re: Suzuki fa50 low top speed need help, tried everything.

Hey there, okay so I reinstalled an original carburetor off of a different fa50 same thing runs exactly the same as the chinese carburetor. I currently have it running on mixed gas and just left the oil pump there but removed the oil tank....I had some gas leaks which I took care of and also had an electrical issue but all of that has been fixed. I am literally tired of working on this thing lol. I've replaced I think every part. Changed the case oil today. It could be an air leak that's something I've not checked. Any idea which lines those are or how do I check for air leaks?

Re: Suzuki fa50 low top speed need help, tried everything.

Also sometimes it surges. Acts like it wants to go faster but then doesnt.

Re: Suzuki fa50 low top speed need help, tried everything.

Here are some pics of my setup. If you see anything that I'm missing let me know.

20200513_155657.jpg
20200513_155651.jpg
20200513_155642.jpg

Re: Suzuki fa50 low top speed need help, tried everything.

Here are more.

20200513_155632.jpg
20200513_155627.jpg

Re: Suzuki fa50 low top speed need help, tried everything.

A few thoughts.

The surging sounds like an air leak. I've had five FA50s and never had an air leak. Check it with the engine running and spray around the engine with carb cleaner. If it makes it stall there's an air leak there.

Check the carb. In the photo the bolt does not look tight (may be a illusion).

Also, the fuel cock is on reserve which will suck the fuel from the sump in the tank through the reserve fuel line. Could be setiment in the sump. Make sure fuel cock is on run.

Re: Suzuki fa50 low top speed need help, tried everything.

Planning to spray the engine shortly. The bolt wasnt attached to the carb because part of the old carb is broken. I dont think it was leaking because on the new carb both bolts work fine and there is no difference. Also this was just something I tried, I removed the air filter and covered the carb intake slowly with my hand thinking that if there was an air leak giving it less air might make a difference. It just slowly ran worse and died. I watched videos today online of fa50s running and they run way better than mine does lol. Soon as I hit 17 mph it starts this farting sound and that's it no more speed. I have to be missing something. Gonna start with checking for air leaks next. See how that goes.

Re: Suzuki fa50 low top speed need help, tried everything.

Last photo there is a nipple on the carb without a hose on it?!? What went there, maybe plug that up, is your filter open cell foam?

Re: Suzuki fa50 low top speed need help, tried everything.

> Stephen Keller Wrote:

> -------------------------------------------------------

> Last photo there is a nipple on the carb without a hose on it?!? What

> went there, maybe plug that up, is your filter open cell foam?

That is a vent . It should have a hose leading down under the motor .

If left as is , crud could get into the carb .(edited)

Re: Suzuki fa50 low top speed need help, tried everything.

Also looks like an open port right above the (idle?) screw? When you get this sorted, next step is a new rear tire! Fender too if you still have it.

Re: Suzuki fa50 low top speed need help, tried everything.

Dr. Mantis Toboggan M.D. /

You're more than likely sucking in air through the oil pump since you don't have the nipple plugged after you removed the oil line. Plug that up with vacuum cap and see how it runs. Also, if you're not using the oil pump and premixing instead then you should remove the internal gear that connects the oil pump to the transmission and reinstall the pump without it. You can also remove the entire oil pump and install a block off plate. Make your own or buy the one they have on Treats.

https://www.treatland.tv/MLM-suzuki-fa50-oil-injection-block-off-plate-p/mlm-fa50-oil-plate-1100.htm?gclid=EAIaIQobChMIk8H8gfez6QIVB43ICh2bDQuXEAQYASABEgJvJvD_BwE

Re: Suzuki fa50 low top speed need help, tried everything.

I've no idea what that is. The original carburetor was the same way when I got it. And I have the original air filter, i dont know if the foam inside is original or not.

Re: Suzuki fa50 low top speed need help, tried everything.

Oh I am planning on doing this thing up right if I ever get this issue fixed. New tires, cleaned up, etc. Just not gonna put any more money into it until I get the slow issue taken care of. Got some carburetor cleaner today, gonna try spraying it down tomorrow to see if there is an air leak and go from there.

Re: Suzuki fa50 low top speed need help, tried everything.

The oil pump was being used until very recently when I stopped using it to check to see if that was causing my slow issue. Like I said earlier in the posts I feel like I've checked and changed everything on this moped lol. It runs the same plugged and unplugged tried it both ways. Also if and when i get this thing running correctly my mind says get rid of the stupid oil pump and i want to. But my issue is I've read that it ouls areas that the mixed gas doesnt cover? My only worry is that i will blow it up eventually if i dont run the oil pump. Am i correct or is it okay to just get rid of the pump and not worry about hurting the motor?

Re: Suzuki fa50 low top speed need help, tried everything.

I've had numerous fa50and fz50s never ever had a problem with the oil pump! I really don't understand why some guys have an issue with it. All of mine ripped! Even had 1 that I ported the shit out of had boost ports shaved the deck and head , 3 or 4 base gaskets so the exhaust port is uncovered, that thing did 47mph. Still had the oil injection. My question is did this bike by any chance come from Iowa? Iowa bike only have 2 transfer ports not 3 and have a top speed of 20mph.

Re: Suzuki fa50 low top speed need help, tried everything.

Sounds like an fa50... I've seen a few that run up to 20mph and then give out. I would do rebuild the top end with new gaskets and deck the head. Cook the stock pipe to clear out the carbon, or get a new one... Then i'd probably run a SHA with a new intake and see how that does...

Re: Suzuki fa50 low top speed need help, tried everything.

Sha is junk! The 1st chance I get it's history. I'll stick with a mikuni better throttle response.

Re: Suzuki fa50 low top speed need help, tried everything.

Found these on letgo you might wanna jump on it before they're gone. 2 Simonini pipes probably the best pipe ever made.

https://www.letgo.com/es-us/amp/i/2x-simonini-exhausts-suzuki-fa50-moped_71570893-f161-45e3-8af9-c99644f0a86d (edited)

Re: Suzuki fa50 low top speed need help, tried everything.

These 2 images 1 is an iowa type cylinder with 2 transfers the other is 3 transfers.

Screenshot_20200515-033116_Chrome.jpg
Screenshot_20200515-032957_eBay.jpg

Re: Suzuki fa50 low top speed need help, tried everything.

^ never knew Suzuki did the Iowa thing...

Re: Suzuki fa50 low top speed need help, tried everything.

I've only seen 1!

Re: Suzuki fa50 low top speed need help, tried everything.

It's not an Iowa bike it came from New York city originally and I dont think the motor needs rebuilt I checked compression amd it's like 130 psi and the exhaust is fine I removed it and ran it no change amd installed a different fa50 exhaust still no change and I cleaned it.

Re: Suzuki fa50 low top speed need help, tried everything.

Have you checked the crank seals?

Re: Suzuki fa50 low top speed need help, tried everything.

Is the carb adjusted exactly to factory specs ?

Re: Suzuki fa50 low top speed need help, tried everything.

Re: Suzuki fa50 low top speed need help, tried everything.

Air leak guys?

Re: Suzuki fa50 low top speed need help, tried everything.

That would be an air leak! Check the carburetor gasket as well as the intake to case gasket. That was the area you sprayed. Maybe even the base gasket.

Re: Suzuki fa50 low top speed need help, tried everything.

punkrock randy /

Sucking in too much air(unmetered), not enough fuel. Causing the four stroking sound that you’re hearing. No longer to be referred to as “farting” sounds. Let us know how she rips after you get it sussed out :-)

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