Author Topic: reed valve mont cappras  (Read 7079 times)

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mx250

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Re: reed valve mont cappras
« Reply #15 on: September 16, 2010, 04:05:31 pm »

montman

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Re: reed valve mont cappras
« Reply #16 on: September 16, 2010, 05:45:11 pm »
A lot of interesting comments i was not intending to try to reed valve my monts but with all the talk in the UK of reed valve,more horsepower,better throttle responce it does make you start to think.Its also interesting to hear comments like great handling and great bikes and while i agree with all things 414 on that not a lot of people in the UK will agree they all think they are camels in the handling area and were out dated when they were new.I can remember in the early to mid 1970's along with bultaco they were the bike to have (in the UK anyway) then after 1975 they started to go downhill in the riders views what with the maico's and jap bikes coming through even now in what we call the twin shock class its nearly all maico's i can not recall seeing a mont in a lineup for ages(pehaps its time i stoped riding modern bikes and gave my monts another blast)so is it down to what shocks you have OHLINS/BETORS as from factory/AVAX(any body heard of them)or what do you sugest also forks while i think MAZOKS were the best at the time  do you just run with stock settings or has anyone moded or added anything to them.One thing that annoyed me more than anything with a mont was the bogging on bottom end this used to happen when the bike was a few months old(6 or more)even after new piston/ring timing correct carb jets correct and clean in fact every thing you could check replace we did apart from a new carb and yet you could still sit there throttle open with the bike not picking up for a good few seconds any one else come across this?.

All Things 414

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Re: reed valve mont cappras
« Reply #17 on: September 16, 2010, 06:10:25 pm »
Can't say I've discovered that problem Montman (thank gawd!). I run everything standard apart from the slightly lower compression. I have the timing set at 3mm BTDC. 40mm Bing with factory jetting. I am having problems with suitable crank seals and I've been made aware that I should use gaskets on the seal carriers instead of Three Bond (I had the clutch case preasurising on the weekend due to this).

I have a set of YSS shocks on the rear with adjustable pre-load and rebound damping (we can run them over here) and a set of YSS emulators in the forks. The only thing I did was shorten the shocks to 360mm as I'm a bit of a short-arse but this doesn't seem to have changed the the way it steers that much. It hooks up very well.

I reckon' they'll run with anything else out there. :)

There's a big gap between this one and the rest of the field..... :P  (pics thanks to Yamatragic)











« Last Edit: September 17, 2010, 06:23:07 am by All Things 414 »

montynut

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Re: reed valve mont cappras
« Reply #18 on: September 16, 2010, 06:54:00 pm »
I don't see how you could use more low/mid and mid/high rev power than the Monties make standard. My VB360 was setting quick times at the Canberra track last Saturday (before the bloody Motoplat let all the smoke out) using two gears 2nd and 3rd ;D. I can assure you it must have been the bike because the riders nothing special ::)

The H7 250 has a reed valve and to be honest I think it was only put on to satisfy the fashion gods.
« Last Edit: September 16, 2010, 06:59:20 pm by montynut »

montynut

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Re: reed valve mont cappras
« Reply #19 on: September 16, 2010, 07:01:06 pm »
Yeh it took another 2 laps before '48' lapped you ;D ;D ;D ;D Sorry Ross

Offline Lozza

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Re: reed valve mont cappras
« Reply #20 on: September 16, 2010, 07:02:38 pm »
firko get Treaders to explain what the relationship is between the reed and the pipe at BDC.That will explain how piston ports just cannot compete with reed valves. I don't think the 250 Maico is probably the best example to use either, the scavenging on that cylinder is not very good that's the first thing to address .Big trap with reed conversions is to go too big and next is removing those 'restrictions' like stuffers followed by bending the stops back as far as possible.. Big bores are a bit of a law unto themselves, the abudence of torque wallpapers over lots of issues.Go down to 125's and a reed engine is far more enjoyable to ride than the piston port.
When dyno figures are mentioned there is little talk about the shape or the 'area under the curve' which is far more important than the peak figure.
Jesus only loves two strokes