1994 Elite S SA50P Cold Start Problem

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schwarz633
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1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

My son has this derestricted 1994 SA50P that I just made some minor repairs to. He had complained about it not starting when it was cold (<30┬░F). I replaced the chinese aftermarket carb with an eBay original Keihin (78 jet), installed an air filter element, new plug, and upgraded the throttle cable to a Y-type. I connected the bystarter to 12VDC and it seemed to extend properly. I was working on it inside (60┬░F) and it was starting just fine. When I delivered it to him it was about 30┬░F and we had trouble getting it started. Once started, the idle was high and dropped down over a period of a few minutes. It seems to run fine (~40 MPH), but still hard starting. It has 7000 miles on it and my gut feel is that the compression is low. It just seems to spin over a little too easy with the kick starter. Could low compression cause these symptoms? Would a set of rings be worth the time and trouble?
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Re: 1994 Elite S SA50P Cold Start Problem

Post by Meatball »

A quick compression test would answer/eliminate the possibility. If you don't have a tester, theyre pretty cheap at Harbor Freight. No need to run out and buy an expensive one unless youre needing it for other tasks. Theres a Auto Parts store near my house that actually will loan me one for nothing. Others will rent me one for a few bucks.

High idle when cold is normal. That's the bystarter doing its job.

You claim its "derestricted"...explain whats been done to achieve this. A derestricted SA50 has a 82-85 main jet. However, this would not affect the tough starts.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

Meatball wrote:A quick compression test would answer/eliminate the possibility. If you don't have a tester, theyre pretty cheap at Harbor Freight. No need to run out and buy an expensive one unless youre needing it for other tasks. Theres a Auto Parts store near my house that actually will loan me one for nothing. Others will rent me one for a few bucks.

High idle when cold is normal. That's the bystarter doing its job.

You claim its "derestricted"...explain whats been done to achieve this. A derestricted SA50 has a 82-85 main jet. However, this would not affect the tough starts.
It was derestricted by the PO. I know that the exhaust restriction has been removed. I'm assuming that the variator plate was removed, the spring on the rear pulley appears to be aftermarket (colored), the airbox restriction has been removed, and the jet is a 78, as far I can recall. I assumed that was correct based on this: http://www.hondaspree.net/phpBB3/viewto ... 20&t=31822. And the oil pump was zip-tied open when we got it.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by Meloshameless »

Hard starts usually means not enoug fuel. I would try to source the 82-85 jet as meat suggested. U can also try turning the air screw all the way in, then half turn out that'll richen up the air fuel mixture and help it start better.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by eclark5483 »

Airbox restrictions removed?
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

schwarz633 wrote:
Meatball wrote:A quick compression test would answer/eliminate the possibility. If you don't have a tester, theyre pretty cheap at Harbor Freight. No need to run out and buy an expensive one unless youre needing it for other tasks. Theres a Auto Parts store near my house that actually will loan me one for nothing. Others will rent me one for a few bucks.

High idle when cold is normal. That's the bystarter doing its job.

You claim its "derestricted"...explain whats been done to achieve this. A derestricted SA50 has a 82-85 main jet. However, this would not affect the tough starts.
It was derestricted by the PO. I know that the exhaust restriction has been removed. I'm assuming that the variator plate was removed, the spring on the rear pulley appears to be aftermarket (colored), the airbox restriction has been removed, and the jet is a 78, as far I can recall. I assumed that was correct based on this: http://www.hondaspree.net/phpBB3/viewto ... 20&t=31822. And the oil pump was zip-tied open when we got it.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by eclark5483 »

Right, what I was getting at, is that might be your problem.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

I advised him to try to cover the opening in the top left corner of the airbox while starting, but I think access is limited by the plastic lower. I then suggested sliding a rag up there with a butter knife or something, but haven't heard back from him about that.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

I removed the tab opening up the second passage and plugged the (9) 1/4" holes the PO had drilled.

http://www.hondaspree.net/phpBB3/viewto ... =4&t=34041
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Re: 1994 Elite S SA50P Cold Start Problem

Post by bonesv »

Sometimes the problem is caused by multiple mis-adjustments or changes made unknown to the owner. You must become familiar with this scooter or it could be tricky to correct. Below is a link to the free pdf service manual download.
One possibility that may be contributing to the difficulty is the oil pump may be leaking oil into the motor causing the problem you describe. This is my experience. Many older models, but not all, of the sa50 elite oil pumps can leak oil either into the carburetor, eventually finding it's way into the case, or directly into the motor usually after sitting for a few days or maybe weeks without being started and burning off all the accumulated oil.
The other contributing possibility may be the air/fuel mixture screw setting. Once again, from my own experience, the #78 main jet is sufficient as I run the same #78 in one of my own scooters without a problem. This is providing that there are no air leaks causing a lean condition. The service manual gives the correct starting-point setting of the air/fuel mixture screw. As mentioned you could richen the idle mixture by turning the screw clock-wise, but I would start at about 1 full turn or so out from closed position. http://hondaspree.net/wiki/index.php5?t ... ce_Manuals
You may also try using a starting fluid spray which contains a lubricant just to bring it to start. Once fired and warmed up, you can adjust the idle mixture setting.
I hope this helps your situation and let us know how you resolve it so others looking for help can find it.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

Well, I had to make the 4 hour round trip to retrieve the scooter this morning, as it had absolutely refused to start. I wanted to get it back anyway, as the Y throttle cable I had installed was a little wonky and I have a new one on the way from Taz. I did a compression check, 125 PSI (spec is 114-171). Not great, but in spec. Discovered that the ignition control module had died. It's very convenient to have a parts scooter. My plan is to drill a small hole in the rear facing carb side of the air box that will accept the plastic tube from a can of starting fluid. I'm figuring that he can give it a shot of ether when it won't start in the cold temperatures.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by vintagegarage »

Just to be sure, I would remove the cover to the airbox, and tape up the square hole marked in red that you cut per the directions in the link you referenced... i.e.
http://www.hondaspree.net/phpBB3/viewto ... =4&t=34041

Very easy to do, and it may shed some light on the problem.

I de-restricted two Elite Ss using the same instructions that you did, thinking that the Elite SRs from the same year came from Honda with the second hole punched out. However, when I finally bought a couple of Elite SRs, both had only one of the two square holes punched out, and both go 37 mph. The OEM Elite SR cover is still available from Honda, and only has one hole punched out. The other square hole only has the small slot in it just like yours did originally.

After experimenting quite a bit, and playing around with mainjets and a temp gauge. I could never see that removing the second hole accomplished anything other than making the Elite S scooter with stock piston and cylinder louder. I could never make the de-restricted Elite S scooter go faster with the second hole opened up using a stock S piston and cylinder.

When the scooter is warmed up and idling, and you turn in the idle air bleed screw, I assume that the engine stops. Is this correct? It is a simple test to prove that your idle circuit is working properly. If you screw in the air bleed screw all the way and the engine doesn't stop, then the engine is idling on the main jet, and the idle circuit is plugged up. If the idle circuit is plugged up, it will be tough to start when cold.

Almost lastly, make sure you do the bystarter check that is described in the service manual. The brass piston in the bystarter may be stuck in the extended position. I have seen them get stuck in the warm (i.e extended) position when the brass piston gets jambed up in the carb body. When that happens, you won't get the enrichment you need for cold starts.

Lastly, make sure the tiny hole that in the carb float bowl that permits gasoline to enter the bystarter fuel chamber is clear. With the float bowl on your workbench and sitting level, fill the float bowl with gasoline or thinner, and watch the bystarter fuel chamber. The bystarter fuel chamber should fill in a minute or less, if the hole is clear. If the chamber doesn't fill, the hole is plugged up, and you won't get enrichment at cold startup.

There is a good discussion of this in wikispreedia.. including many photos:

http://hondaspree.net/wiki/index.php5?t ... ture_Guide
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

vintagegarage wrote:Just to be sure, I would remove the cover to the airbox, and tape up the square hole marked in red that you cut per the directions in the link you referenced... i.e.
http://www.hondaspree.net/phpBB3/viewto ... =4&t=34041

Very easy to do, and it may shed some light on the problem.

I de-restricted two Elite Ss using the same instructions that you did, thinking that the Elite SRs from the same year came from Honda with the second hole punched out. However, when I finally bought a couple of Elite SRs, both had only one of the two square holes punched out, and both go 37 mph. The OEM Elite SR cover is still available from Honda, and only has one hole punched out. The other square hole only has the small slot in it just like yours did originally.

After experimenting quite a bit, and playing around with mainjets and a temp gauge. I could never see that removing the second hole accomplished anything other than making the Elite S scooter with stock piston and cylinder louder. I could never make the de-restricted Elite S scooter go faster with the second hole opened up using a stock S piston and cylinder.

When the scooter is warmed up and idling, and you turn in the idle air bleed screw, I assume that the engine stops. Is this correct? It is a simple test to prove that your idle circuit is working properly. If you screw in the air bleed screw all the way and the engine doesn't stop, then the engine is idling on the main jet, and the idle circuit is plugged up. If the idle circuit is plugged up, it will be tough to start when cold.

Almost lastly, make sure you do the bystarter check that is described in the service manual. The brass piston in the bystarter may be stuck in the extended position. I have seen them get stuck in the warm (i.e extended) position when the brass piston gets jambed up in the carb body. When that happens, you won't get the enrichment you need for cold starts.

Lastly, make sure the tiny hole that in the carb float bowl that permits gasoline to enter the bystarter fuel chamber is clear. With the float bowl on your workbench and sitting level, fill the float bowl with gasoline or thinner, and watch the bystarter fuel chamber. The bystarter fuel chamber should fill in a minute or less, if the hole is clear. If the chamber doesn't fill, the hole is plugged up, and you won't get enrichment at cold startup.

There is a good discussion of this in wikispreedia.. including many photos:

http://hondaspree.net/wiki/index.php5?t ... ture_Guide
All good points. I will remove, disassemble, and inspect the carb as illustrated in the WikiSpreedia link you provided. I did have it apart and gave it a cursory cleaning, but didn't remove the emulsion tube or inspect the passages.
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Re: 1994 Elite S SA50P Cold Start Problem

Post by schwarz633 »

I took the carb apart again and everything looked good to me. Got the emulsion tube out this time and it was clean. Confirmed the jet is a 78. Didn't closed the second air box hole. I also raised the needle on the slide one click, it was in the middle notch. The idle air bleed screw is not screwed in all the way.

So it's starting right up in the cold, fast idling, and running great if you give it 20 seconds or so to warm up. It may bog a little bit after a couple of minutes of running as the bystarter is backing off and the engine is warming up, but that only happens once if at all and then it's good to go.

I had discovered that the fuel shutoff valve was open all the time, which I didn't think would be a problem, but I swapped that out with a functioning one from my parts bike.

I think the real solution here was raising the needle, but since I was making other changes at the same time, I'm not really sure.
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