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Discussion Starter #1
So I have been tinkering with this bike for a while. I have pod filters on it, changed the jets in the carb, cleaned the carb out, put on new gas lines, and have changed the spark plugs all in an effort to try and fix this problem. I CANNOT get it more power or up to top speed. its an 81 cm400T with only 12000 on it. Oil and oil filter have been replaced and its not backfiring or anything bad or weird. It sounds great and perfect when running as well. But, when I want to rev up the speed I'm putting out 10,000 and only getting up to 60 or 65mph. Is there a place I should check for an air leak? Somewhere it's not getting compression? I know the jets are the right size and fitted correctly and everything because I bought them off of a previous thread here. But for the life of me I can not figure out why I am getting such little power out of it! HELP NEEDED
 

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What exhaust are you running? It is very difficult to get better power output than stock. The factory intake is tuned.

When you say 10,000 (RPM) at 60-65, what gear are you in? Does it bog down when you shift? If so the engine is not making the factory rated output. How did it run with the stock airflter?
 

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Discussion Starter #3
when I'm doing 10,000 and only getting 65 its in top gear, so 5th. and no, its perfectly clean when I upshift and downshift. And it didn't have the airbox on it when I bought it so I'm not sure about that. But I don't think that just the pod filters can take away that much power. I've read I'm supposed to be at around 6000 rpm and going 60 in 5th gear. and that would be a HUGE difference.
 

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Sensei
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What is your compression PSI?.....
At what RPM are you upshifting?
 

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If your engine is turning 10,000 rpm and you're in 5th gear at 60-65 mph your clutch is slipping.
(Unless there have been some serious sprocket changes).
 

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Discussion Starter #7
I'v already done that test and the clutch was totally fine. I mean, i could trya nd just replace the clutch but I would rather not waste more money on something that I don't think would be the problem. But in a previous thread I had people say that and tell me how to test it and it passed all the specs for the test.
 

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Sensei
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Measure it with a compression gauge....

But, FIRST, what brand and type oil are you using...... Is it JASO- MA spec?
 
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Discussion Starter #9
How much should I be getting out when I do the compression test? and okay ill try running it higher before I shift but will that help me reach a higher top speed? I have also added a tooth to the back to get more high end speed and it did nothing at all.
Also, thank you to every who is responding, this bike looks stellar and I'm just trying to get it to run that way too.
 

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I think you missed the point. If the engine is turning 10,000 rpm in 5th gear at 60-65 mph, the clutch is slipping.

An improperly adjusted clutch cable could cause it. Improper oil, as Steve suggested, is another possibility.

Adding a tooth to the rear sprocket will decrease top speed (relative to engine speed), not increase it.

Gotta go to a meeting, will check back in later.
 

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Sensei
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Adding a tooth to the rear (wheel?) sprocket will REDUCE top speed
And YES, your clutch is slipping... We just need to find Why it slips....
 

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Discussion Starter #12
well I just replaced the oil and filter with 15W40 oil which is what was recommended. I had adjusted the clutch wiring and thought I had it...
 

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Discussion Starter #13
okay, so if I am slipping then how would I get it not to slip? just adjust the clutch wire? Or have to replace the clutch all together?
 

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Sensei
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Depends on WHY it is slipping...... 540-525-5199
 

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Discussion Starter #15
OK, so I did some searching and found some stuff on youtube and different forums, and before I go an buy new clutch plates I'm going to try screwing in the clutch wire a little more so the knuckle of the wire is further back and see if that does anything for helping it not slip. I'll keep you all updated.
 

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Sensei
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While you may be using the correct weight of oil, it may NOT be the correct type.....

Normal automotive oils tend to have friction modifying/reducing additives which makes them unsuitable for wet clutch applications....

Rather than randomly play with the cable, why not attempt to adjust it properly as described in the FSM?

Phone me at that number I posted before to discuss further
 

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What would cause it to be slipping?
You may have used the recommended weight (or viscosity grade), but did you use oil with the correct specification? Automotive oils have friction modifiers that can cause your clutch to slip. You want to make sure you used an oil specified for use in motorcycles with wet clutches, JASO-MA.
 

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I think I can safely assume you do not have the factory service manual.

PM sent.

Call Steve.
 
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