MX FCR Project (Monster 750).

Started by koko64, January 30, 2020, 07:39:46 AM

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koko64

All that being said, the pilot jet will be most affected. The adjustable slow air jet screw could be tweaked 1/2 a turn here or there to compensate. Good to see such a deep main jet sitting linear to the needle jet, so no worries there.
2015 Scrambler 800

koko64

2015 Scrambler 800

koko64

2015 Scrambler 800

koko64

#153
I can report that the carbs perform really well despite one carb having a partially blocked pilot circuit that stubbornly resists sonic cleaning. I played with the adjustable slow air jet screw and idle mixture screw as a work around. Nifty.

I was often in a higher gear using less throttle input for more response, all the more impressive since the stock CV carbs had a quick action throttle. No more whisky throttle as Speeddog calls it. The response is direct and linear with no more waiting. On more than one occasion I was in top gear thinking I was in 4th, such was the torque increase. Very impressive.

I was of the opinion that stock CV carbs posed less of a restriction to the 750 motor than the 900. I was wrong.
2015 Scrambler 800

MonsterHPD

Monster 900-2002 (sold, alive and well in the UK), 749R / 1100 HYM combo for track days, wifes / my Monster Dark 800-2003 (not entirely "Dark" anymore and a personal favourite) , 50% of 900SSie -2000 track bike for rainy days-now with tuned ST2 motor and Microtec ECU. Also parked due to having been T-boned on track.

Von Eisen



Quote from: koko64 on April 16, 2020, 02:05:35 AM
Hey VE, any updates?

  Waiting on jets atm, old carbs are refitted so he can get out on the road for some exercise ... Meanwhile the project FCR are resting  [roll]

  Your road test sounds positive, have you got/fitted the elbows ?

fcr45 by simon lane, on Flickr

koko64

I'm using the modified elbows/boots until the new ones arrive. One boot developed a rip from the clamp, so the bike is sidelined until the other boots arrive from the States. I could refit the CV carbs, but cant bring myself to do it! [laugh] I guess I'll finish all the other little details now including fitting the Ohlins shock.
2015 Scrambler 800

greenmonster

QuoteRunning an Ignitech programable ignition and tps is another project for another day. 

That day is getting closer... ;) ;D

How much f a complete FX set?
M900 -97 
MTS 1100s  -07

koko64

#158
 ;D

I'm actually quite happy with the oem Kokusan boxes on a low comp 750. The smaller bore, combustion chamber and low compression seem to work well with the aggressive advance curve angle/graph. I have only dealt with one hi comp 750 and the stock ignition worked fine with higher octane fuel. I only have one customer with a 750. The attitude is bigger is better in this wide land, but I'm a 750 convert now.
The temptation for me is using an Ignitech to facilitate a tps, and ignoring the siren call of hi comp, 900 cams and 900 valves. The original concept for the scrambler was to be able to use any fuel available in more remote areas, so standard comp is good.
2015 Scrambler 800

Howie

Quote from: koko64 on April 22, 2020, 03:12:55 PM
;D

I'm actually quite happy with the oem Kokusan boxes on a low comp 750. The smaller bore, combustion chamber and low compression seem to tolerate the aggressive advance curve angle/graph.

More like curb :P  I wonder what a more sophisticated curve might do for pulling from low RPMs.   

Speeddog

Quote from: howie on April 22, 2020, 03:44:11 PM
More like curb :P  I wonder what a more sophisticated curve might do for pulling from low RPMs.   

Makes em real smooth.
You can even adjust the rpm while it's on the choke, totally civilized.
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koko64

Quote from: howie on April 22, 2020, 03:44:11 PM
More like curb :P  I wonder what a more sophisticated curve might do for pulling from low RPMs.   
Quote from: Speeddog on April 22, 2020, 04:02:44 PM
Makes em real smooth.
You can even adjust the rpm while it's on the choke, totally civilized.

I certainly found that with modified 900/944's. I'm so impressed with how smooth the 750s are.
2015 Scrambler 800

koko64

Quote from: Von Eisen on April 21, 2020, 11:23:46 PM

 Waiting on jets atm, old carbs are refitted so he can get out on the road for some exercise ... Meanwhile the project FCR are resting  [roll]

 Your road test sounds positive, have you got/fitted the elbows ?

Manifold boots finally arrived from the US and were fitted.  They fitted beautifully with no modification and tilted the carbs 10-15 degrees eliminating any clearance issues. Thanks heaps mate for putting me onto these boots as they solved a lot of issues. I ordered another pair for spares.
2015 Scrambler 800

Von Eisen


Excellent, pleased they did the job for you  [thumbsup] ... Will be interested to know your thoughts on float level.

Still waiting on jets, things are moving slowly within shipping services atm   [bang] ... Will post an update when I have something

koko64

Get onto Show n Go in SA and pay for a courier parcel. [thumbsup]

Niche Cycle are a new resource, thanks again. Those boots made it easy. I'll be noting on road performance and plug colours re float level. No anomolies yet but for some internal grime in the RHS carb that wont budge despite sonic cleaning, etc. I think a high quality fuel cleaner and long ride are in order. Performance otherwise is excellent with increased response and low and mid range torque. We have effectively increased intact tract lengths by an inch or two. The lower rpm torque is very good now, but maybe with a drop off at peak rpm.  However the intake port to cylinder volume ratio has improved and maybe that will offset any peak rpm drop off. Not sure. Well see.
2015 Scrambler 800