Got the Airsal A55 kit running

Got the ported Airsal kit working and I am not to pleased with the results for all the work I did on it. I had 0.035" milled of the top of the cylinder(due to lame tolerances), 0.8mm squish clearance, WPC of the Piston, Cylinder and rings, heat dispersing coating on the outside of the Cylinder and head, TBC coating on dome.

Porting is raising the exhaust port 3mm, the transfers 2mm, straighting out the intake and exhaust ports, smoothing insides of the transfers, especially where the splitters are, trimming the Piston skirt on the intake side 2mm. Combustion chamber is polished.

Here is my list of lame stuff with the Airsal kit, takes a different short reach Spark Plug, no mention of this in any sort of instructions, ruined an expensive iridium plug and possibly damaged the Piston (I could see it gouged a deep hole in the dome) when I tried to kick it over hard the first time with a bunch of four letter words, bad nikasil, plating had to get redone, porus casting had to fill with JB weld to avoid air leaks, lots of core shift on transfers. Don't recommend the Airsal, go with some sort of Puch kit and make it work instead.

Carb is a Delorto 19mm PHBG on a custom intake manifold. Jetting is 83 main 35 pilot, needle in leanest position. It was faster on a 82 main but engine sounded like it was detonating so I had to richen it up. (maybe the compression ratio is too high the airsal chamber is really small compared to stock, not to mention the milling). The intake manifold I had made is probably too long for tuning for the RPM my pipe and porting want.

Pipe is a Simonetti Puch pipe and its probably too radical for this Engine. Porting, pipe and Intake Manifold probably don't match too good.

I am dispointed in the mid range power, low end is ok but its dead in the middle and the top end is pretty good, hits a powerband starting at 40 mph and pulls until the speedo needle spins all the way around and hits the zero peg. Didnt know it would go that far! I guess this is way over 50 mph. The engine is screaming, I am worried that it will blow up. I am running 26/22 gearing. I don't want to go to a 27 front because it will take forever to get through the boggy mid range.

We really need to find a good way to raise the shift point for these built engines. A shift point of about 35 mph would make this haul. Anyone have any ideas, I am running a green first gear clutch spring on the second gear clutch but this isn't enough. Anyone try to lighten the clutch shoes or something?

Sorry I didnt get a GPS reading but the clutch blew up on the first run where I got the jetting close and I was going to use the GPS next but boom. Probably we need to figure out a stronger clutch as well. Anyone ever figure out how to improve a Tomos clutch?

I am sorta disappointed, I don't think this is much faster than any other big Bore A55 even with all of my extra little tricks, I do weigh 200 lbs though.

Time to get a spare case, weld it up and bore it so I can run a Gila cylinder on it. 65cc doesnt cut it.

Re: Got the Airsal A55 kit running

) Cupermcnewbster ( /

50+ isn't enough for you?

I agree its not the best kit ever, but for under $200 for cylinder and head with porting similar to that of a metra 80, its not a horrible deal. If you buy airsal, you should know what that means quality wise.

Also, this is the only a55 specific kit, but any puch kit will work.

Re: Got the Airsal A55 kit running

I think nearly everyone with an airsal can hit 50. Heck some people do 52-53 with 50cc motors, I got 48 mph with the 50cc motor and probably could do 50 if I was not so fat!

I didnt know much about mopeds when I bought the kit. Should have done my homework. I thought I could build something special but I guess not. My usual attention to details didnt seem to help. I should have started with a gila or metrakit.

Perhaps pegging the speedo all the way around without tucking for a sort of heavy guy is ok? It seems may people around here hit 60 mph.

I got some A35 cases lying around and will probably send those off to be welded and machined.

Sorta worried about the clutch durabilty.

Re: Got the Airsal A55 kit running

) Cupermcnewbster ( /

a55 clutches are pathetic. A35 isn't much better, but I've heard the a3 clutches are much better, and apparently the older ones work in the newer cases.

are you still running the stock a55 ignition? They are limiting and don't allow it to rev much over 10000, so that could be your issue. Try an a35 cdi (and stator) and it will be faster.

Re: Got the Airsal A55 kit running

John Joedicke /

A35 and A55 clutches are the same and A3 are not interchangable. Smaller pins on actual shoes, and bores and splines different.

Re: Got the Airsal A55 kit running

I am running an A35 ignition. The A35 Ignition doesnt retard as much as the A55 at high revs but I think the higher compression motor needs it because I have to jet too rich to keep it from detonating. I noticed that really high performance two strokes like my Aprilia RS250 retard the spark to almost TDC at high revs. I think this is partialy to boost EGT's to keep the pipe in tune longer but maybe to reduce detonation as a two storke doesnt have time to cool the cylinder.

With a smaller jet, its a lot faster but the engine really sounds like it gonna blow up at high rpm, you can hear what really sounds like detonation up on top, with richer jetting its quieter but still sounds iffy.

With an air cooled two stroke its hard to tell if its the fins are ringing or detonating. The stock motor used to sound like it was detonating but I could hold it WOT for miles making that noise and it never blew up.

I wonder how fast this would be with a 170 lb person on and 27/22 gearing, still its not a rocket like what some of you guys build here.

Re: Got the Airsal A55 kit running

Here is a picture.

Re: Got the Airsal A55 kit running

Re: Got the Airsal A55 kit running

hahahaha, good to see another SR person rocking mopeds also.

Re: Got the Airsal A55 kit running

BootyClap Ninja /

That is a huge fucking fairing...zomg.

Re: Got the Airsal A55 kit running

my experiment to try to reduce drag

Re: Got the Airsal A55 kit running

I am running 27/20 gearing on my white tomos a35 airsal reedvalve kit and it doesn't shift out of first until 30 and with a sha 14/14 I top out right at 50 on a gps and can carry two people at 45 no problem.

Re: Got the Airsal A55 kit running

Did you do anything to delay the shift until 30 mph?

Re: Got the Airsal A55 kit running

I put on the 20 tooth sprocket the gearing did it , pain in the ass to mill the wheel to take the sprocket.

Re: Got the Airsal A55 kit running

and I have 15000 miles on my motor I know 50 is not the fastest thing out there but I can drive it wide open for hours and I mean hours with out a problem and I get about 70 miles to the gallon

Re: Got the Airsal A55 kit running

Well Marvin at Myrons rode it and he liked it, he told me that this was the fastest A55 he has ridden so far. I respect his opinion and experiance highly. Maybe I was just expecting too much and am too hard on myself.

After my pretty sucessful Aprilia SR50 build, I was expecting gains like I got with that engine.

Re: Got the Airsal A55 kit running

Let me qualify Marvins statement, the fastest A55 with an A55 specific kit on it.

Re: Got the Airsal A55 kit running

haha..... nice catch Mike.... you riding tomorrow???

Re: Got the Airsal A55 kit running

as long as it's not raining!

Re: Got the Airsal A55 kit running

mike kojima /

It ran really hard, probably hitting around 60 mph once I got the jetting right, then it seized, I guess it wasnt that right.

Re: Got the Airsal A55 kit running

Sorry to hear that. It's tempting to make the jetting a little too right. Is it totally destroyed?

Re: Got the Airsal A55 kit running

Yes the plating is messed up, it was a pretty solid seize. I have so much time into the porting that I am probably going to replate the cylinder. Does anyone know if the piston, rings and pin for the airsal kit is avalible by themselfs?

Looking at the parts, there is no sign of detonation on the piston or combustion chamber, the plug looks perfect, medium brown with no signs of overheating or detonation. There is some light browning on the undercrown of the pistons indicating that it got somewhat hot.

The engine was really dry inside. I think that the oil injection doesnt pump enough oil for really high revs. I know I was taking a risk with this but expermenting is sometimes risky.

So the next time I am going to run a little more piston to wall clearance, jet a little richer, check my ring end gaps and run some premix in the mixture.

Its a shame, my prior disapointment was caused by not having the proper plug, the spark was being introduced low in the chamber and the big protrusion was proably causing a weird burn and detonation. When I installed the proper plug, the engine ran hard and I was pretty happy.

It seemed to have good power in the hills and ran great right up to when it seized.

I have a polini kit but I want to try to dial in the airsal to get good information out for those who want to try direct bolt in kits so I will repair the airsal and continue to dial it in if I can get the piston.

Re: Got the Airsal A55 kit running

I think sells individual parts from kit. Not sure but it's worth a look.

Re: Got the Airsal A55 kit running

did you even brack it in first

my 65mk is way faster now that it brok in and i am runing 25:1

and you are runing it at 50:1 f that run at lest 32:1

you have to think the a55 was not ment to hit high rpms so it need at least 32:1

Re: Got the Airsal A55 kit running

those oil injection pumps are junk on tomos'. you really just gotta switch to premix, and run a slightly larger jet knowing that now some portion of the fuel is actually going to be oil coming through the jet!!!

Re: Got the Airsal A55 kit running

i like tomos oil injection alot, but its no good for kits. i always say just run both premix and oil injection that way you can cut the throttle down hills.

siezed the same kit twice, 4 rings later i think its dead.


Re: Got the Airsal A55 kit running

instead of cutting the throttle down the hill you can cut the ignition and keep the throttle open, jake brake style. that will keep the air pump going, with fuel and oil, and you won't seize.

Re: Got the Airsal A55 kit running

The problem is very simple. You need more oil mike. Alot of people confuse rich/lean mixtures with oil mixtures. The fact of the matter is that you were probably running a decent air/fuel mixture, but you were probably not running enough oil, hence the inside of your motor was dry.

First off, the oil injection for tomos. The oil injection was meant specifically for the stock 14mm carb. It provides a 50:1 oil mixture for the 14mm carb only!!! If you look closely, the oil injection is purely mechanical and provides oil on a linear basis according to RPMs. If you're using the 19 Dell, you're definitely going to need to premix.

Another note, when people play with oil mixture, they forget one thing! When you increase oil say from 50:1 to 40:1, you are going to need to upjet. The reason is that because you have more oil in your gas mixture, the less gas molecules you have going into your combustion chamber.

Hope this helps!

Re: Got the Airsal A55 kit running

That is what I was thinking exactly. The Tomos oil injection is very simple and provides more oil on an RPM dependent basis only. The stock Tomos is in a very mild state of tune.

Higher performance two strokes have more sophisticated oil metering. On my Aprilia RS50 and RS250 for instance the oil pump has a variable drive that pumps more oil with more throttle opening. RS250 guys don't remove the oil pump because the engine actualy likes it better and lives longer than premixing does.

For my next Tomos motor, I am either going to run premix or run the oil pump with some premix. I ride my moped a lot so premixing all the time is a hassel.

The next motor is going to use a 80cc metrakit cylinder. I sent the case out to be welded an machined. I'll probably fix my ported airsal and sell it to someone who wants a fast 65cc cylinder.

Re: Got the Airsal A55 kit running

holy crap dude, sounds like some really good stuff. fantastic workmanship, but as i've found with a lot of people who go from other motorsports to mopeds, there is quite a bit of nuance to these funny little beasts.

the simonini is a dog in the midrange, you're going to have to lighten the second gear shoes to get that back, you'd probably be much happier with a different pipe. i dont like that one very much but it does kill on the top end.

definitely siezed due to the oil pump issue, premix and rich at that. Aprilla designs the RS50 at probably 6 or 7 to one safety factor for all engineered components, so when you double the performance you are still well within the design limits, tomos engineers at a 3-4 safety factor, if that, so quadrupling the power output, which has a 10-20 fold impact on stress in the parts, is really exceeding the limits of the parts. the main challenge with these isn't so much getting the most power out of them, its getting the most power without having to rebuild it every weekend.

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