Bad rev issue or idle issue please help

170 is WAY lean, totally bone stock is like 220-230, depending on year.

A bored cylinder isn't considered a mod. It adds very little displacement or power.
I also don’t have a stock carb, I have a Keihin PWK airstyker I believe, and I also don’t believe they produce a 220-230, because I just ordered a kit of main and idle jets so I can replace the ones I have now and the main only goes up to 200
 
170 is WAY lean, totally bone stock is like 220-230, depending on year.

A bored cylinder isn't considered a mod. It adds very little displacement or power.
I also don’t have a stock carb, I have a Keihin PWK airstyker I believe, and I also don’t believe they produce a 220-230 for my carb, because I just ordered a kit of main and idle jets so I can replace the ones I have now and the main only goes up to 200
 
I also don’t have a stock carb, I have a Keihin PWK airstyker I believe, and I also don’t believe they produce a 220-230 for my carb, because I just ordered a kit of main and idle jets so I can replace the ones I have now and the main only goes up to 200

And now ................. the rest of the story :rolleyes:
Keihin main jet numbers are about half of a Mikuni, a 300 Mikuni is about a 150 Keihin. Pilot Jets are the opposite numberring system.

Have you actually done a plug chop? Leak down test?
 
And now ................. the rest of the story :rolleyes:
Keihin main jet numbers are about half of a Mikuni, a 300 Mikuni is about a 150 Keihin. Pilot Jets are the opposite numberring system.

Have you actually done a plug chop? Leak down test?
I have the leak down tester ordered just waiting on shipment, have not actually leak down tested it yet
 
First air leak found! Thanks awk for the tool! Best 40$ I spent on this thing adding a picture of where the leak is too. It’s right where the carb gets to the engine, bubbles flew! So there’s a large air leak there, it’s not letting any pressure build so there’s could be more but all the air leaks right there as soon as I pump it
 
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First air leak found! Thanks awk for the tool! Best 40$ I spent on this thing adding a picture of where the leak is too. It’s right where the carb gets to the engine, bubbles flew! So there’s a large air leak there, it’s not letting any pressure build so there’s could be more but all the air leaks right there as soon as I pump it
 

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Carb boot/manifold cracked ??

@Awk : She's a squirter :D:D:D
Well I removed the intake to locate a crack or anything noticeable and found it looks like the previous person to do engine work used silicone as the gasket around the intake, which my best guess leads me to conclude it eroded away after the amount of years it sat without running, here’s 3 more pictures, if anyone could help point me in the direction of a replacement, or a gasket I need, it looks in good condition but I can’t find anything on amazon for this
 

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Just cleaned off the old gasket/seal that the previous owner had put on, and I cleaned the surfaces, and used red RTV gasket maker on the surfaces and I’m gonna let that sit for a good 24 hours then retest for other leaks
 
24 hours later. Leak tested again after correcting the first leak, it held 5 PSI for 8 minutes and I released the pressure assuming that was good, put back the exhaust and the carb and the body pieces I had removed, and began to start the quad, it started great! I left it idle for about 3 minutes and I was thinking to myself “wow! It’s fixed!” And I jinxed myself, 30 seconds later it began revving itself to max again, but there’s no new or preexisting leak. I’m about out of ideas, I’m about to say I’ll buy a brand new carb and start there this time around, if y’all have a good place to get a carb can you please let me know it? Thank you, thanks guys for all your help so far, this has been a tough long process but it’s slowly coming together!
 
Thats a CT-240 cylinder you have, it uses the 6 bolt CR250 intake, so that's the gaskets you'll need to use on that, which is what I'd do instead of the RTV sealant. you do not want to damage that cylinder/piston

you do not need a new carb, that's a great carb for your setup, it just needs adjusted and tuned.
have you cleaned it properly ?
https://www.blasterforum.com/threads/how-to-clean-your-carbureutor.254/

air filter clean and oiled ?

tell us exactly what jetting is in that carb ?
pilot jet, airscrew setting, needle # and clip setting slot, slide #, and main jet ?
(50 pilot, 1.5 turns out on airscrew, CEL needle in middle slot, #6 slide, 155-162 main jet)

I'm going to assume that carb came with the CT cylinder as they sold them as a kit....
240cc top end, 36mm carb and right bend CT pipe, and should be closely jetted for that setup, but each engine is slightly different as well as temps and elevation which will effect jetting

if it's still leak free ? and you're having idle rev issues....
is the slide closing completely ?
idle screw not set to hold slide open too far ?
have you checked/set the float height and tuned the airscrew ?

https://www.blasterforum.com/threads/float-heights-and-how-to-adjust-them.50565/

https://www.blasterforum.com/threads/adjusting-your-airscrew-pilot-jet.51060/
 
I have a 170 main jet, 60 idle jet I believe, my float height I adjusted to the post you showed me which said 16mm float fight at a 45 degree angle I think, the throttle slide in the carb is not fully closed there’s about a half to 3/4 of an inch of an opening at the bottom of the slide, I’m currently not home, I will send pictures from the inside of the carb at the slide once I get home. I also cleaned the carb to that post as well, I will update this post more once I get home
 
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slide in the carb is not fully closed there’s about a half to 3/4 of an inch of an opening at the bottom of the slide

that could be a problem and would produce a high idle as you describe
find out why it's hanging open so far..... throttle cable adjusted or routed wrong, or idle screw holding it open too far ?
 
On the inside of the slide bore is a small "nub" that keeps the slide from spinning around. Check that it hasn't come loose. To late for me to go digging in the garage to look at carb to give more details about this. Tomorrow, IF I remember:rolleyes:
 
On the inside of the slide bore is a small "nub" that keeps the slide from spinning around. Check that it hasn't come loose. To late for me to go digging in the garage to look at carb to give more details about this. Tomorrow, IF I remember:rolleyes:
I’ll do that in the morn, I as well agree it is a bit late but I’m always on every 3-6 hours lol if I was better at this small engine and carb work I’d figure out how to apply for staff because I’m on that much LOL! But all jokes aside yes tomorrow around 1pm Eastern (Pennsylvania) time, I’ll go take a look down the carb for what you’re describing