Need help, might of got scammed smh

[Serdrix]

Alright so I used to have a Polaris express 300. Great model, only thing Polaris made that was reliable.
Never had any issues.

Fast forward to about 3 days ago I got my first manual.

Yamaha blaster 200 bored to 250.
Guy that did it works at Honda on cars and atvs so I thought “I might be getting something good here.”

He says he did top end and bottom end rebuild but it’s been in the garage for a year so the carb needs cleaning, no problem, ran great the first 2 days I had it so I figured “what the hell, clean it when it starts to give me problems” now on the express model I had, when the carb gave problems, it just wouldn’t turn over or something simple like that.

Well today I was riding and all of a sudden it started bogging.
Would rev up fine in idle but in 2nd or 3rd it would just bog about 1/2 throttle.

Worried it’s a piston issue so I took the carb off, cleaned it, did some tuning but like I said, used to express carb so this was a bit different, and put it back on, but as I was putting it back on, I noticed the guy did a half ass job on the tors delete, (he just cut the wires off) so I took the tors apart and made my own idle screw which works AWESOME!! Saves drilling into the carb and everything.

Anyway, I put it on and after doing some testing, the idle was finally good.

I just need some advice on how to tune the carb as far as the float level because it still overflows and maybe some pics of worn down float needles. Mine looked okay but I’m not for sure.

Also forgot to mention I did a compression test on the engine while cold.
Around 8 kicks with throttle wide open, the needle on the tester stops at 120.

I feel that is a little low on a 250 bore but not entirely sure.
It’s also stock carb so I wasn’t sure if a stock carb would fit a 250 bore, maybe so.

It’s a mikuni. Just give me some ideas.

Did I get scammed??

Side note: takes like 20 kicks when the engine is cold to start it, again might be carb that just needs tuning but want some thoughts on that too.

 

[Serdrix]

Alright, so update, got the carb on today and tested it, fine when running cool but once it gets hot it starts to bog, like bad. Do you think it’s the stator? At first I was suspecting reed valves but then it hit me (earlier it revved fine but now it’s not good even in neutral) also after revving it and bogging it won’t idle it will cut off.

 

[Larry's Shee]

First, stop running it until you figure out the problem !! You might save a lot of money.

Second, you can't bore a Blaster to a 250 ! You can bore it .050" over but that's not 250cc !!

Next I think you mean revs up fine in neutral, not idle.

Make sure the TORS brain is disconnected, 3 wire plug under the hood, if you have a 2003+ search how to do it.
Go to the carb subsection in engine forum should be pinned threads with everything you need, or use sear h function, it works good here.

Follow the the thread on carb cleaning, and also " Almost free way to fix A leaky carb". A proper carb clean and set the float is all you need. Don't bother with rebuild kits !! All that ever wears out is the float needle/seat and the O-ring on out side of seat. The problem is that the jets may not be right.

You do realize that a Blaster mixes gas with oil, right?

 

[Larry's Shee]

DON'T BUY CHEAP CHINESE PARTS !!

 

[Serdrix]

First, stop running it until you figure out the problem !! You might save a lot of money.

Second, you can't bore a Blaster to a 250 ! You can bore it .050" over but that's not 250cc !!

Next I think you mean revs up fine in neutral, not idle.

Make sure the TORS brain is disconnected, 3 wire plug under the hood, if you have a 2003+ search how to do it.
Go to the carb subsection in engine forum should be pinned threads with everything you need, or use sear h function, it works good here.

Follow the the thread on carb cleaning, and also " Almost free way to fix A leaky carb". A proper carb clean and set the float is all you need. Don't bother with rebuild kits !! All that ever wears out is the float needle/seat and the O-ring on out side of seat. The problem is that the jets may not be right.

You do realize that a Blaster mixes gas with oil, right?

Hey Larry! Thanks for responding.

Okay so there’s been a lot that has happen since this post.

I’ve not ran it since yesterday because I decided to tear it down.

The TORS system is disconnected.
The wires were cut right at the base of the tors on top of the carb.

When I took the carb off to clean it, I decided to pull out all the electrics of the tors system including the spring because they were rusted!!

Where the tors system was inside the box, I put a long screw that is basically my idle screw now, works great.

Anyway, the oil injection system is capped off.

The guy I got it from was mixing 40:1 but I was thinking since it’s bored to 250 (at least I thought) I better mix 32:1 to be safe.

I’ll dig in more into the tors system brain because that could be a possible issue.

Also, I got some big news from the previous owner yesterday.

He finally said “oh I didn’t bore it, the guy I got it from bored it and he told me he bored it 30 over...” so I’m going to measure today to see what it actually is.

I have some pics I’m going to tag with this reply because I tore it down to the top of the head yesterday, I’m not sure what to look for as far as wear so I need some opinions.

Thanks!




https://ibb.co/hc03FJp
https://ibb.co/88mJ8SN
https://ibb.co/myCDh9d
https://ibb.co/VHptxhN
https://ibb.co/Wvc9KYz
https://ibb.co/5nfwcf1

 

[Larry's Shee]

Hope others will chime in also. Doesn't look good, but I've seen worse. I don't like the scoring above the exhaust port. Plus couple of spots look like damage to the edge of the crown..

To late now but you should have done a compression test first. Maybe even a leak down before you tore it down..

One nice thing is that you have a rechambered head !!

Now you have to decide if you want to invest money into it..
That will determine the advice that I, or others may give you.

Let us know

 

[Serdrix]

Hope others will chime in also. Doesn't look good, but I've seen worse. I don't like the scoring above the exhaust port. Plus couple of spots look like damage to the edge of the crown..

To late now but you should have done a compression test first. Maybe even a leak down before you tore it down..

One nice thing is that you have a rechambered head !!

Now you have to decide if you want to invest money into it..
That will determine the advice that I, or others may give you.

Let us know

thanks for the reply. So before I tore it down I did do a compression test and it said 120 PSI. Throttle wide open tested on warm AND cold engine. Both read the same.

 

[Serdrix]

thanks for the reply. So before I tore it down I did do a compression test and it said 120 PSI. Throttle wide open tested on warm AND cold engine. Both read the same.

Also,
The damage that’s on the crown I thought was damage too but it was actually just shiny spots where there was 0 carbon buildup. Hard to tell from pics. What do you mean it’s to late to do another compression test? I tore this thing down in like 20 minutes I’m sure I can get it back together in no time lol. Once last thing, explain what a rechambered head is, kinda confused. And yes, I’m willing to put money into it.

 

[Serdrix]

I figured I would upload this video. It might be a simple tors issue but I really don’t know. When I listen to it on the video, it sounds almost like how Polaris limits your speed in reverse on your atv until you press reverse override. Super familiar and doesn’t sounds natural.

 

[Slydog]

The head was milled way down and the combustion chamber was recut to a better design.
Great cheap mod if done correctly

 

[Serdrix]

The head was milled way down and the combustion chamber was recut to a better design.
Great cheap mod if done correctly

I feel like it was done correctly, I just feel like there’s something with electrical that is cutting the spark down. What do you think as far as the video goes? I had the throttle slowly and fully to kind of show what it does.

 

[Larry's Shee]

Did you use a new head gasket or animal the old one?
Really should do a leak down test now. It's SOP on two strokes after you have them apart. It's to ensure you don't have an air leak, which will cause a lean condition, which will melt your piston

*Standard Operating Procedure

Have you cleaned the carb and set the float? Air filter clean? Good plug? Is TORS disabled? What jets are in it? Do you have any mods (Modifications) ??

 

[Serdrix]

Did you use a new head gasket or animal the old one?
Really should do a leak down test now. It's SOP on two strokes after you have them apart. It's to ensure you don't have an air leak, which will cause a lean condition, which will melt your piston

*Standard Operating Procedure

Have you cleaned the carb and set the float? Air filter clean? Good plug? Is TORS disabled? What jets are in it? Do you have any mods (Modifications) ??

okay, so I’ll go pick up a leak down tester today and preform one before running it again. I haven’t ran it since so tore it down and it’s still apart. The guy I got it from put a new piston in it. Wiesco piston. The air of lid has been removed. Added fmf pipe. Main jet is stock 230 size. I know the jet size is supposed to be a bit bigger with the fmf pipe and air box lid removed but what I don’t understand is I was riding it one day and it was running great and then out of no where it starts bogging. I just feel like the jet size wouldn’t cause issues out of no where. I’ll still change them if it needs to be. I’ve already cleaned the carb but I’ll get a caliper and set the float today. Air filter is brand new and cleaned out through the tube to the carb. New plug, tors system is half assed disabled. (I’ll send pics in a little bit) and that’s pretty much it.

ALSO, wym new head gasket? The guy that put in the new piston has put in a new gasket and still looks like it’s in great shape. Do I need a new one every time I open the top end? Also I haven’t done anything like removing the piston, all I have done is took off the top of the engine.

 

[LJulian80]

Old thread I know.. The exhaust scoring is probably from being to lean from the pipe and no air box lid. Yes you need to use new gaskets everytime. It probably got warm from running lean is why it started to bog but most definitely should of been bogging on top end anyway. I actually seen a Blaster with Pro Circuit Platinum pipe, 304 silencer, open lid, high flow air filter. It had the stock 230 main jet. It ran perfect until very tippy top of the top end then it would stutter some. It still runs and ran that 230 jet for years like that, it now has a 250 jet.