Hey all, I've got a tomos with an airsal kit and a 15mm dellorto carb. I slapped on a tecno side bleed with end bleed pipe and a parmakit cdi and I'm hitting about 40 with stock gearing, I feel like it should be able to go faster and I've chased down any and all air leaks, and the carb is tuned well, timing is stock. Would advancing the timing help? Maybe gearing? bigger carb? any tips would be helpful.
Tomos tuning help
Re: Tomos tuning help
Drop to a 22t rear sprocket
Re: Tomos tuning help
It's already got a 22 tooth rear
Re: Tomos tuning help
Have you re-jetted the carb after adding the pipe?
Re: Tomos tuning help
yeah I rejetted the carb, its running a size 74 jet, dellorto carb.
Re: Tomos tuning help
40 is pretty right with a stock tomos. 74 seems high for stock. I am running close to that in 70cc setups. I will have to see what I have in my tomos right now tho. I do have a super special slide that lets me upjet a touch more.
Re: Tomos tuning help
Its not stock, has the airsal 70cc kit on it
Re: Tomos tuning help
Could worn clutch pads cause low speeds?
Re: Tomos tuning help
You can get a 20t rear sprocket for some tomos wheels. You can also get larger sprockets for the front. Anything over 28t will require some grinding on the case to allow the chain to clear it. But it is the area next to the fly wheel so you can potentially cut into it without causing any issues.
The 70cc kit should get you up into the mid 40's pretty easy so there could be a number of things preventing that.
Transmission functioning properly? No drag in the gears?
Wheel bearings are good still? No drag on those?
Brakes are set properly and not grabbing the hub without the lever being pulled?
These are all easy things to check on which will definitely affect the speed of the bike.
Re: Tomos tuning help
The clutch pads would not cause things to go slow, but not function at all. If they have glazed over they could slip and not grab well. Causing you to go slow but you would feel them just slipping.
The spring on the clutches can have an affect on quickness but not really top speeds. If you have a stock spring on your second gear still then it will spin and engage early before you have a chance to get into the powerband. This will cause the bike to slow and bog a bit but ideally it should slowly get back up to speed.
Again this would not be limiting any top speeds.
Tomos stock cdi and points both seem to cut out around 9k to 10.5k RPMs no one on here has ever given a great answer to why that is, but it always seems to be a thing. But that again you can feel this while riding. It will feel like the bike is still gaining speed at the top, then all of a sudden just kind of hits a wall and won't go past that rpm even tho the bike feels like it should. Then it almost starts lurching from trying to go a little faster but then gets "limited" back down a bit. It is kind of weird and entirely frustrating.
Re: Tomos tuning help
I think I once or twice hit that rpm limit in first, but never in second gear. My pads aren't glazed over just hella worn so I'll check that off my list. Still gonna replace em though. The brakes have been sticking a lot recently, so I'll try and fix that up as much as I can. Wheel bearings should be okay as well. How would I go about checking the transmission? As far as I could tell everything inside seemed alright last time I opened it up.
Re: Tomos tuning help
finished up checking on everything recently, the brakes were sticking and i got those to not stick, wheel bearings are all fine, nothing is rubbing and the jetting still seems fine. only weird thing is this thick smoke coming out of the carburetor, doesn't really smell like gas and I'm wondering if its transmission fluid leaking into the crankcase.
Re: Tomos tuning help
If the acceleration is good then you can try a 27f sprocket. Hitting the rev limiter in 1st sounds strange. Stock normally shifts pretty quick. So smokes while running or when u turn off?
Re: Tomos tuning help
Smoke or vapor coming out of the carburetor would indicate to me that your reed valve is in need of attention or replacement. The reeds should be sitting closed tightly when the motor isn't running. If there is vapor coming out, it tells me the crankcase gasses are escaping.
Re: Tomos tuning help
If you ever hit that kind of RPMs in first then there is an issue with your second gear not engaging properly. Stock transmission tomos usually shift into second at about 15 to 20mph which is right around 5k. You can get them to stall longer with a stronger 2nd gear spring but still not up to 10k. That would do unhappy things to the transmission.
If you opened up the transmission and didn't see chunks of metal, broken bits of a part or any damaged gears then it is probably fine overall.
Re: Tomos tuning help
Oh shit, thanks philip i didnt even bother to think about the fact that my reeds should be closed. they're brand new so its probably a problem with the gaskets, ill check when I get home from college.
Re: Tomos tuning help
Hey there everyone, cracked it open and took a look inside. The reeds were indeed stuck open due to a shitty paper gasket, fixed that up. I then decided to open up the side, cause y'know I could feel that they were worn out. The clutch pads actually weren't worn out, they were just fucking gone. Probably grinded a shit ton of metal flakes into the atf, resulting in that horrible colored transmission fluid. I'm gonna put some new pads on, gears look alright and all the bearings are okay. Let you know how it goes when I put it all back together.
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