A55 running up to 340F

ERIC from Idaho! /

Hey guys, I just rebuilt my Tomos Streetmate and the temp is running crazy high! So high that if I hit the kill switch it will run without spark! DEISEL POWER! I've been trying to break it in at ~15mph, but after about 15 minutes it runs rough and is ridiculously hot! I'm running a 2fastmoto 70cc kit and an aftermarket exhaust and K&N airfilter. I was using a 44mm Airsal kit before this that had a terrible life and death. I don't know what carb I have on it, I'm not really sure how to tell. The bike seems to be running fine and I'm currently mixed at 40:1 for the breakin. I lubed the entire engine up while putting it back together with some leftover 10w-30 I had hanging around. Any tips on how to not melt this thing to the ground while maybe fixing the heat problem?

-Eric

Re: A55 running up to 340F

id like to see a moped 'dieseling', 340 totally normal.

Re: A55 running up to 340F

ERIC from Idaho! /

340F is normal during breakin? This is my first breakin on a tiny thumper. I'll try to grab a video of the awesome diesel action lol

Re: A55 running up to 340F

You lubed the cylinder with 10w30? No. Use 2 stroke oil.

Are you tuning the carburetor for this setup?

You're probably running lean/totally untuned and possibly have air leaks as well.

The only time i've seen a moped "dieseling" is when my stupid crank case drain bolt rattled out of my e50 during a long rally ride causing a crazy lean condition on a hot cylinder. Could not shut that fucker off, revving to the moon on the centerstand with no throttle input. had to pull the spark plug boot.

Re: A55 running up to 340F

ERIC from Idaho! /

I pulled the boot when the kill switch didn't work...it kept running. So I pulled the intake off and put my hand over it. I seriously have no idea how to tune a carb and there are 0 shops where I live that are willing to look at a moped. I am in moped hater land. Even scooters are hated around here. People have to defend their masculinity by driving super fast, loud and powerful vehicles, or they may shift into homosexuality. Anyone have a good guide for learning to tune an A55?

Re: A55 running up to 340F

Post a pic of your carb and this forum can probably help identify what type and range of jets you should get for tuning. With the symptoms you're describing it's also possible your magneto side seal is bad giving you a huge leak.

How did your last kit die?

Re: A55 running up to 340F

ERIC from Idaho! /

The piston melted to the head because the previous owner didn't realize it was 0 clearance. It punched it for a long time, but eventually all those little aluminum pieces made their way around the whole engine. "I think I found the source of all that ticking!"

I'll grab a pic as quickly as I can get over to the shop :)

Re: A55 running up to 340F

Overpriced Parts /

> pat splat Wrote:

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

> id like to see a moped 'dieseling', 340 totally normal.

I had a Yamaha ? It may have been a Suzuki I believe Enduro 100 dirtbike that would diesel/run with the ignition off, timing was all messed up though, lotta things were messed up, and it actually ate and burned up plugs in a few hundred mi, It was weird on many a hot hot day, I’d shut off and it would just go to clonk ker clonk ker clunk ker clunk, for like 20-30 seconds or more, I normally would tilt the bike to one side and then it would stop,

340 Head temps aren’t crazy but rarely does my tomos ever get close to that temperature

Re: A55 running up to 340F

Upjet probably but keep running 40:1. Use the good stuff, at least semi-synthetic 2-stroke.

Re: A55 running up to 340F

ERIC from Idaho! /

What do you think guys? Is this the right carb for the job?

IMG_20190510_180142.jpg

Re: A55 running up to 340F

If there's an oiling inlet nipple on the other side of that carb and you're running premix instead of the oil pump, make sure it's capped off

Re: A55 running up to 340F

ERIC from Idaho! /

It is. There is a short tube with a fastener ran into the end of it. It doesn't leak air. The poor moped ran up to 450F today! At 20mph

Re: A55 running up to 340F

Based on the old tuning spreadsheet, people are reporting using anywhere from a #60 - #78 main jet with an airsal kit and pipe. Here's a link to the jets that carb uses.

Re: A55 running up to 340F

the a55 air filter box richens up the fuel mixiture, if no filter add a few jet sizes then a few for kit. try running w your choke on.

Re: A55 running up to 340F

> ERIC from Idaho! Wrote:

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

> It is. There is a short tube with a fastener ran into the end of it. It

> doesn't leak air. The poor moped ran up to 450F today! At 20mph

Your probably running a crazy tight squish band with shity fuel. To much compression and the temps are running sky high.

Re: A55 running up to 340F

whats your timing set at? what are you measuring your temps with? what variables did you change between runs?seems like a crazy jump in temp from 340F-450F.

Re: A55 running up to 340F

ERIC from Idaho! /

Thank you for the information :) I'm riding in the daytime instead of after dark. I also tried to adjust the idle down a bit. I think it's just running really lean. Can I post a pic of the plug and get some opinions? (edited)

Re: A55 running up to 340F

read up on how a carbutetor works and what a main jet is.

Re: A55 running up to 340F

The a55 Airsal assembled with thr gaskets it comes with has a super mega tight squish and a really small combustion chamber. I on a daily rider set up I always space it out with a 1mm spacer and thin gaskets on both sides. That usually puts the squish around 1.2 without a head gasket.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account