monty conrod alternatives

[montynut]

I fitted an Italkit Conrod to my VF250 and had the issue with the L/E bearing width. It required a stepped set of thrust washers to be made to allow 0.25 - 0.45mm float in the piston and the same for the L/E bearing. I had them made from very high quality steel which had a lowcoefficient of expansion commonly used in Turbine bolts . It has done around 3hrs of racing and when dismantled it was all perfect 

I also found the same issue with the L/E width among other things when I dismantled my VG414 and had to make stepped thrusts to replace the suspect arrangement that had been installed. Luckily befoire I had tried to run it

[Lozza]

Thrusts at the top or bottom doesn't really matter.Smaller big end eye diameter means has a bearing with more rollers in it which gives a higher redline rpm. 

[Captain Bilko]

I use H7 360 rods in mine. I did however have to have some of the case milled out where the edge of the rod went through them (it just touched). I use a KTM small end bearing which is the same size as the standard 414 one.

[montynut]

I had them made from very high quality steel which had a lowcoefficient of expansion commonly used in Turbine bolts .

This bit was just for Ross and it recieved the desired reaction

[dutchtwinshock]

The VB 250/360 and the 414 all use the same rod.  Not sure why you
would have to use the special piston if using the Italkit rod kit.  I sell the
this rod kit for $225. USD.   The main problem I have is that the upper rod
bearing is the incorrect length as used on the VB.  Can't seem to find the
correct bearing anywhere.

Sorry i was mistaken it was not a special piston but Keven Breedom told me the italkit competition rod make use off Hoekle barrel type big end.
I don`t know what that is.

The italkitrod you selling is it the DC5098R?

i saw on the partlist that even the cranks vb250(early)-vb360 are the same


Is there is also a relationship between crankwheels diameter and inner or outer flywheel rotor?

Montesa parts are confusing a bit ,its seem the montesa engineers puzzled a bit with a cupple of parts

i gona make a claer parts interference list  i will post it soon

[dutchtwinshock]

so if the 250 ve-vg used a shorter rod (116mm)
and the vb used the longer rod (124mm)
and they have all the same stroke there must be a change in piston compression hight,or the barrel(liner) hight is changed.
when i look to the italkit piston list ,i see that al va-vg have the same piston .
so montesa must have lowered the barrels ve-vg isn`t 

thats why the intake tube changed (bend up) otherwise the carburator touched the crankcase

now i am even more confuse because i have a 73m14525 ( VE250 ) engine in parts .It has a 124 mm rod .
in fact thats  impossible it must be 116mm

[cappra]

There is a mistake in the Italkit catalog.  The VA piston is not the same as the VG.
VR, V75 and the VA use one style of piston, VB, VE, VF, VG use another.
The motors that use the short rod (116mm) use a shorter cylinder.  They have
one less cooling fin.  The crank assembly's for the VB 250 and 360 are the same.  414 looks the same,
but for the location of the crankpin.  Flywheel type would be dependant on the type of power delivery
the factory was looking for.  All of the Montesa motoplat ignitions will interchange with each other.
Generally the bigger size motors went with a heavier mag, except in the case of Ross's 414 in which he
fitted an internal rotor magneto!

 The rod kit I have onhand is BC.5098R

[414VG]

There is a mistake in the Italkit catalog.  The VA piston is not the same as the VG.
VR, V75 and the VA use one style of piston, VB, VE, VF, VG use another.
The motors that use the short rod (116mm) use a shorter cylinder.  They have
one less cooling fin.  The crank assembly's for the VB 250 and 360 are the same.  414 looks the same,
but for the location of the crankpin.  Flywheel type would be dependant on the type of power delivery
the factory was looking for.  All of the Montesa motoplat ignitions will interchange with each other.
Generally the bigger size motors went with a heavier mag, except in the case of Ross's 414 in which he
fitted an internal rotor magneto!

 The rod kit I have onhand is BC.5098R

Apart fron the 414VG Jared, which has a different motoplat from what went before..
Sandy

[cappra]

Not sure I understand the question.  Please elaborate..

[montynut]

There is a mistake in the Italkit catalog.  The VA piston is not the same as the VG.
VR, V75 and the VA use one style of piston, VB, VE, VF, VG use another.
The motors that use the short rod (116mm) use a shorter cylinder.  They have
one less cooling fin.  The crank assembly's for the VB 250 and 360 are the same.  414 looks the same,
but for the location of the crankpin.  Flywheel type would be dependant on the type of power delivery
the factory was looking for.  All of the Montesa motoplat ignitions will interchange with each other.
Generally the bigger size motors went with a heavier mag, except in the case of Ross's 414 in which he
fitted an internal rotor magneto!

 The rod kit I have onhand is BC.5098R

Apart fron the 414VG Jared, which has a different motoplat from what went before..
Sandy

The VG414 has the same weight flywheel as the H6 360 (very large) although it has the 33x1.5mm puller size. The H6 also has a second flywheel on the primary drive side. As Jared says I believe you could fit an earlier (lighter) ignition to the VG but the tractable power from the heavy flywheel and what I can see altered porting on the VG I'm not sure it would be better. I have tried a couple of different flywheel weights on my VB360 and the standard one is best. Lighter makes slick tracks less than fun. When Ross had the bike he had an internal rotor PVL and he said starting was easy (good spark) but it was interesting when traction was not perfect. I don't think I would be able to ride it as the difference between a 900g and 1100g flywheel was very noticeable. The 1100 g one is standard. The VG414 is around 1800g and as you know requires the large magneto cover

[Captain Bilko]

The part number for the KTM s/e bearings that I've been using is:
544 30034 000

I don't know off-hand what size that is but I've been slappin' them into my 414's every time i've had the top off 'em (with the shimming that is there already).

[cappra]

Thanks Ross, will check it out.

[montman]

The VG414 has the same weight flywheel as the H6 360 (very large) although it has the 33x1.5mm puller size. The H6 also has a second flywheel on the primary drive side. As Jared says I believe you could fit an earlier (lighter) ignition to the VG but the tractable power from the heavy flywheel and what I can see altered porting on the VG I'm not sure it would be better. I have tried a couple of different flywheel weights on my VB360 and the standard one is best. Lighter makes slick tracks less than fun. When Ross had the bike he had an internal rotor PVL and he said starting was easy (good spark) but it was interesting when traction was not perfect. I don't think I would be able to ride it as the difference between a 900g and 1100g flywheel was very noticeable. The 1100 g one is standard. The VG414 is around 1800g and as you know requires the large magneto cover
[/quote]
I have just weighed a 250,360 and 414 flywheel 250=950g 360=1100g and 414=1800g as i always thought the 250 was lighter than the 360 flywheel.I also have a H6 360 enduro which had been standing in an outhouse for a few years before i got it and as my knowledge of the enduros is not good thought i would check to see what flywheels it had on and it does indeed have the smallish one on the primary drive but on the motoplat side it has the typical 360(1100g) one on it and not the 1800g that montynut says but does have the large magneto cover strange?.

[montman]

Why when i try to put a quote in is it not like everyone else's

[mx250]

The VG414 has the same weight flywheel as the H6 360 (very large) although it has the 33x1.5mm puller size. The H6 also has a second flywheel on the primary drive side. As Jared says I believe you could fit an earlier (lighter) ignition to the VG but the tractable power from the heavy flywheel and what I can see altered porting on the VG I'm not sure it would be better. I have tried a couple of different flywheel weights on my VB360 and the standard one is best. Lighter makes slick tracks less than fun. When Ross had the bike he had an internal rotor PVL and he said starting was easy (good spark) but it was interesting when traction was not perfect. I don't think I would be able to ride it as the difference between a 900g and 1100g flywheel was very noticeable. The 1100 g one is standard. The VG414 is around 1800g and as you know requires the large magneto cover

Because you cut off the "[quote author=montynut link=topic=17154.msg172054#msg172054 date=1296182190" in front of the quote.