Need some advice on tuning an a55 on tomos racing tt

I know if I search their are tons of threads, and I dug around for an hour. Afrerwards not really feeling much better about how my bike is tuned.

I have tuned other tomos bikes with great success. I had an a55 with a cheaper pipe and airbox mod (snorkle cut off and bored) and it pulled so hard in the 2nd gear power band right to 43ish mph. Even had an a3 that was WAY faster than this a55 with just pipe intake and jet.

The bike i am tuning now is a 2018 tomos racing tt, it has the airbox mod, mlm Cali pipe, and 38 original miles. No air leaks or anything like that, and everything is installed correctly.

So after doing the pipe and airbox mod, I went from 25 idle to 30 idle jet, second from top on needle clip moved to second from bottom, and from 54 main jet to a 68 (as a rich starting point). Was slow, 4 stroked around 25mph. I moved down to a 66 and was still slow, moved down to a 64 and also moved needle to center slot and still no power band in 2nd. Moved to a 62, then 60, and at that point it still seemed very rich, plug was brown in center but black around all edges. I wanted to put in a 58, but I found that was the only one I was missing, so I had to go with a 56 jet. I was worried it would be too lean, but it was still slow, a little more of a tug in 2nd but nothing crazy, maybe a mph or two over stock vs being slower than stock. Also after a 5 minute hard ride, plug was a deep brown all throughout the center right to the base of the ceramic. And black around the inner metal edges.

Now as a reminder, stock was a 54, now I'm running a 56,do you guys think the jump was too far and I should order a 57, 58 and 59 jet. Or is it really possible this was jetted a bit rich from the factory, to the point I'd need stock size jet with a pipe? I'll add a pic of the plug when I can.

20220412_165616_copy_2016x1512.jpg

Re: Need some advice on tuning an a55 on tomos racing tt

picture shows stock pipe? yet you say MLM Cali?

did you add any holes in the rear half of the air-box to increase airflow? sounds like you aren't getting enough air. Last stock-ish Tomos build had like 4x 1/2" holes drilled in the rear part of the air-box.

you could also have an ignition problem.

Re: Need some advice on tuning an a55 on tomos racing tt

In my experience, and the experience granted by the many people who have helped me on this forum, if you're running too rich and the jet is almost stock, there's something else wrong.

Is your airflow being restricted at all in any way? Have you tried removing your air box all together to see if there was a change.

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

It's a new bike, it had 10 miles when I bought it. And it ran great with the stock pipe, nothing went wrong with the install so I don't think anything is wrong, but I have seen crazier things happen. I have not tried with no airbox, but I definitely can. Since you mention something is probably wrong, I am wondering if because it got 10 Miles in 5 years, maybe oil slowly drained back and saturated the air filter. I will pull the filter and go back up in jet size and see how it feels.

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

I just put the pipe on, the pic is a month ago. From the research I did everyone said not to drill holes or use open air filter because the air in the frame is cooler and more dormant and easier for the engine to inhale. Not saying you are wrong at all, because it does seek to be a divided subject. Wonder if anyone else can confirm on drilling holes?

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

Looks like you may be correct. Came out to take a pic of the plug a try no air box, see a puddle underneath and a steady drip on the mag cover. Wonder if the crank seals are shot :(

20220514_124032_copy_1512x2016.jpg
20220514_124047_copy_2016x1512.jpg

Re: Need some advice on tuning an a55 on tomos racing tt

You do not say what carb you are using, but I would not think you need that idle jet increased just for the adds you made. Main jetting, yes that is going to go up a little, but the idle would stay the same as stock.

Re: Need some advice on tuning an a55 on tomos racing tt

Dirty30 Dillon /

The Racing TT's are my least favorite Tomos ever made.

That said, we were putting a brand new bike on the streets with an Estoril or People's Pipe and smaller rear sprocket for a solid ~38mph.

These motors were notorious for popping RH crank seals; failing ignitions; bad balance.

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

False alarm, the heat made my two stroke oil seap out and drip down the frame to the engine.

20220514_124857.jpg

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

It is a stock carb. I'll try changing the idle jet back.

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

This is my plug color after a hard run on the 56.

20220514_123649_copy_1512x2016.jpg

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

I cleaned the filter, and cut the end off of the filter housing, and jet at 68, runs amazing and pulls like it should. Thanks!!

Re: Need some advice on tuning an a55 on tomos racing tt

> michael patelli wrote:

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

> I cleaned the filter, and cut the end off of the filter housing, and jet

> at 68, runs amazing and pulls like it should. Thanks!!

Those a55 are junk! When the clutch engages all the weight shifts to the tranny side and pulls the magneto bearing from the housing. If I ever kitted one I’d put red thread sealer on the megneto side bearing for extra safety

Re: Need some advice on tuning an a55 on tomos racing tt

I'm glad you got it running send us a picture of the bike the way it looks now, I'm curious since the pic you initially sent is so old. (edited)

Re: Need some advice on tuning an a55 on tomos racing tt

Just remember for that phva and other multi circuit carbs

0 - 1\4 throttle = idle jet

1\4 - 3\4 throttle = needle

3\4 - full throttle = main jet

Obviously the main jet affects the whole system but the carb functions in that order.

Re: Need some advice on tuning an a55 on tomos racing tt

> Jay Rivett wrote:

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

> Just remember for that phva and other multi circuit carbs

>

> 0 - 1\4 throttle = idle jet

>

> 1\4 - 3\4 throttle = needle

>

> 3\4 - full throttle = main jet

>

> Obviously the main jet affects the whole system but the carb functions

> in that order.

i'll second this. not entirely accurate, but a very good approximation.

Re: Need some advice on tuning an a55 on tomos racing tt

michael patelli /

Awesome advice!!!

Re: Need some advice on tuning an a55 on tomos racing tt

Ok, here's the deal, change the slide needle to an A12, it will more than likely tmfux your jetting issue if the airbox is mostly there, if you have a pod filter the A7 is fine but you need like a 68 ish main. Glad you got it sorted already though

Re: Need some advice on tuning an a55 on tomos racing tt

Dirty30 Dillon /

> 666 420 wrote:

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

> > michael patelli wrote:

>

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

>

> > I cleaned the filter, and cut the end off of the filter housing, and

> jet

>

> > at 68, runs amazing and pulls like it should. Thanks!!

>

> Those a55 are junk! When the clutch engages all the weight shifts to the

> tranny side and pulls the magneto bearing from the housing. If I ever

> kitted one I’d put red thread sealer on the megneto side bearing for

> extra safety

I've worked on MANY of this era A55 and never seen this happen. What you're describing seems like a ln assembly error.

I'm guessing you've never owned or worked on one of the last generation Tomos', so why make this up?

Also, "red thread sealer" is not what you would use, even if this were a problem. 4 seconds of Googling would show you that.

Re: Need some advice on tuning an a55 on tomos racing tt

I'll take all his a55 motors, I love them

Re: Need some advice on tuning an a55 on tomos racing tt

> Dirty30 Dillon wrote:

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

> > 666 420 wrote:

>

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

>

> > > michael patelli wrote:

>

> >

>

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

>

> >

>

> > > I cleaned the filter, and cut the end off of the filter housing, and

>

> > jet

>

> >

>

> > > at 68, runs amazing and pulls like it should. Thanks!!

>

> >

>

> > Those a55 are junk! When the clutch engages all the weight shifts to

> the

>

> > tranny side and pulls the magneto bearing from the housing. If I ever

>

> > kitted one I’d put red thread sealer on the megneto side bearing for

>

> > extra safety

>

> I've worked on MANY of this era A55 and never seen this happen. What

> you're describing seems like a ln assembly error.

>

> I'm guessing you've never owned or worked on one of the last generation

> Tomos', so why make this up?

>

> Also, "red thread sealer" is not what you would use, even if this were a

> problem. 4 seconds of Googling would show you that.

A little threader sealer ant going to hurt to keep the bearing from slipping in the case.

The shitty a55 cases from the Middle East. I bought a silver streetmate with 1,100 miles stock. Wouldn’t shift into second because the entire crank would move to one side! Two weeks later a guy on buy/sell same thing, sliver streetmate. I end up jb welding the bearing in because the case was so fucked up.

Re: Need some advice on tuning an a55 on tomos racing tt

Dirty30 Dillon /

> 666 420 wrote:

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

>

> A little threader sealer ant going to hurt to keep the bearing from

> slipping in the case.

>

> The shitty a55 cases from the Middle East. I bought a silver streetmate

> with 1,100 miles stock. Wouldn’t shift into second because the entire

> crank would move to one side! Two weeks later a guy on buy/sell same

> thing, sliver streetmate. I end up jb welding the bearing in because the

> case was so fucked up.

There is no such thing as "thread sealer," so I'll assume you mean thread locker. In which case, you can use green Loctite bearing retainer, as the red Loctite does not fill gaps.

And saying "shitty A55 cases came from the Middle East" is just about the most misinformed thing you could say.

Every Tomos casting after like 2008 was done in India, under license by Tomos by Kinetic Manufacturing. This year-span includes some of the most lauded years for Tomos, reliability and durability wise.

And most importantly: India is not part of the Middle East.

B)

Re: Need some advice on tuning an a55 on tomos racing tt

> Dirty30 Dillon wrote:

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

> > 666 420 wrote:

>

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

>

> >

>

> > A little threader sealer ant going to hurt to keep the bearing from

>

> > slipping in the case.

>

> >

>

> > The shitty a55 cases from the Middle East. I bought a silver

> streetmate

>

> > with 1,100 miles stock. Wouldn’t shift into second because the entire

>

> > crank would move to one side! Two weeks later a guy on buy/sell same

>

> > thing, sliver streetmate. I end up jb welding the bearing in because

> the

>

> > case was so fucked up.

>

> There is no such thing as "thread sealer," so I'll assume you mean

> thread locker. In which case, you can use green Loctite bearing

> retainer, as the red Loctite does not fill gaps.

>

> And saying "shitty A55 cases came from the Middle East" is just about

> the most misinformed thing you could say.

>

> Every Tomos casting after like 2008 was done in India, under license by

> Tomos by Kinetic Manufacturing. This year-span includes some of the most

> lauded years for Tomos, reliability and durability wise.

>

> And most importantly: India is not part of the Middle East.

>

> B)

Chine Taiwan

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