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Hi guys, as requested, my MSX build thread...
***Note: I have changed to +1 on the front sprocket, hence when I say by bike is doing XX mph, it is infact going 1/15th faster, or approximately 64mph at an indicated 60mph.***
Firstly, I fitted this: http://www.ooracing.com/store/index.php?act=viewProd&productId=3252. Not a straight swap - you have to use a set of 8mm-to-6mm studs (http://www.ooracing.com/store/index.php?act=viewProd&productId=3342), then file out the flange holes slightly - drilling one out to 8mm did the trick.
With hind sight, drilling them both to 8mm might have allowed use of original studs, but I think it's the spacing that's out, not just the stud sizes. The flange-end of the pipe was also too long, meaning neither size studs were long enough. 20 minutes with an angle grinder shortened the end of the pipe enough to get it to fit. As you can see, it's at a true 90 degs to the head, which being slightly inclined upwards means the pipe point too far down. So later I will regrind a slope onto the end of the pipe to make it more level. Noise is a little better (fruity but not too loud), power doesn't seem better or worse yet, but only ridden a mile so far. Weight is a lot better, and looks are SHIT LOADS better (well, I think so!). The baffle is welded in. It takes the form of a tube with the inside end shut, and holes drilled in the sides. I shall be drilling a small hole in the end to let more gas through.
Pipe cost £40, studs £4ish, and postage £6ish.
![Land vehicle Vehicle Tire Automotive tire Motorcycle]()
Experience running the exhaust revealed that as suspected the restrictive baffle is stiffling the engine, and it's actually lost a few mph.
Now on to modifying the exhaust!
Step 1) I tried drilling through the baffle, but even cheap ****** Stainless is too hard for normal HSS drills until you've got a pilot hole. Will have to find a special drill for hardened materials. In the end I ripped the baffle out, which involved pushing it down the pipe, and dremmeling the weld pips out. Then I cut off the end with the angle grinder. To fix it back in I did try solder, but no amount of fluxing and cleaning would let me tin the cheap stainless, so I had to drill it. An hour later after much faffing with various grinders, dremmels, diamond engraves, and old darts, I eventually made two 4mm holes suitable for a pop rivet under the pipe and in the baffle. I did try the pipe with no baffle - literally as restrictive as shouting down a traffic cone! Want your MSX to be louder than a Harley with Screaming Eagles? This will do it! Luckily the very gentle valve timing allows it to run with zero back pressure. With baffle fitted it's fine, a bit noisier, and it definitely revs as per normal now.
![Line Clip art Circle Rectangle]()
Step 2) Sorting the intake. I bought two air filters from ooracing with the exhaust, in the hope that at least one would work. BTW - the throttle body has a 38mm spigot.
The first was the PEX filter. http://www.ooracing.com/store/index.php?act=viewProd&productId=3720
BRILLIANT quality, with plenty of space to mount the intake sensor underneath. Unfortunately it didn't clear the frame. Any one want to buy a filter? £10 including p&p.
The failsafe option was the open stack. http://www.ooracing.com/store/index.php?act=viewProd&productId=3243
(The longest one). This was again lovely quality, shame about it just having a sticker on it instead of an etching or something.
This fitted nicely, but left me with no where to fit the sensor. I drilled a 9mm hole half way down for the sensor, and counter sunk it for the oring seal. I then drilled and tapped two M5x0.8 holes for a pair of stainless allen button bolt I had. These were fitted and marked flush with the inside of the stack. I removed then and trimmed to length, and refreshed the thread with a die. After a good clean I had a lovely stack complete with sensor. Assuming it's an intake temp sensor, being directly in the intake will cool it a little more and make the ECU inject a little extra fuel which will help compensate for the open intake and exhaust until the fuel injector arrives.
The last step was to cut up a plastic sieve to act as a mesh filter. I don't want it swallowing a chunk of grit etc. This was held on by a big jubilee clip. Not very neat, but works beautifully.
All this has enabled me to remove the entire air box assembly. Should help with cooling a bit. Does allow the panels to vibrate a bit as there's nothing to support them at the bottom now. But I might change to a different body set soon. In the mean time I have attached a set of cable ties to pull the panels in at the bottom. This has made them that little bit more rigid.
![Auto part Vehicle Suspension Brake Motorcycle accessories]()
![Auto part Vehicle Engine Car Automotive exterior]()
(for some reason it always rotate the picture of the intake. You can tell where horizontal is by looking at the bricks in the background!)
Following the exhaust and intake installation and modification over 1,000 trouble free miles have been done. The engine revs noticeably better, and higher rpm power is good, with plenty of over-rev. I suspect that the dyno chart would look similar to stock, maybe a little taller at the top, but that it would continue at a high plateau for longer before dropping.
OK, injector has now arrived and been fitted. http://www.rzracing.nl/webshop/honda-msx-high-perfarmance-fuel-injector-yuminashi/ It took a while to come after dispatch - post took about a week. To fit requires temporary removal of airbox and hence bodywork. If, like me, you no longer have the air box, fitting take about 3 minutes. Unplug the electrical cable. Then undo the two 10mm bolts on the mounting. Pull out old injector and mount. Pull old injector out of mount, and replace with new one. About 1 teaspoon of petrol dribbles out, no more, so have a little rag handy. Make sure new o-ring is on injector-end of injector. Refit injector and mount, reattach 10mm bolts. Reattach electrical cable. Take for a ride...
On first firing it up it idled VERY slow, like it was about to stall (900rpm). I took it up the road but past half throttle it began to choke. I made it up to about 47mph like this. A mile up the road I turned around, letting the engine idle again. Suddenly the idle improved back to normal. On the return leg, the engine revved cleanly. Infact, I hit 62mph in 3rd!
Results for a run up a level-ish piece of road, and then return. Very windy today.
Stock: 3rd gear - 57 out, 58 back. 4th gear - 56 out, 57 back.
Light-bore injector: 3rd gear - 58 out, 60 back. 4th gear - 58 out, 59 back.
So it makes a tiny improvement, but not much more than say, tucking in. Fitting very low bars may have same effect. My impression is that it revs better though. In which case on the motorway tomorrow I expect it will be significantly quicker than stock. I will let you know...
***Note: I have changed to +1 on the front sprocket, hence when I say by bike is doing XX mph, it is infact going 1/15th faster, or approximately 64mph at an indicated 60mph.***
Firstly, I fitted this: http://www.ooracing.com/store/index.php?act=viewProd&productId=3252. Not a straight swap - you have to use a set of 8mm-to-6mm studs (http://www.ooracing.com/store/index.php?act=viewProd&productId=3342), then file out the flange holes slightly - drilling one out to 8mm did the trick.
With hind sight, drilling them both to 8mm might have allowed use of original studs, but I think it's the spacing that's out, not just the stud sizes. The flange-end of the pipe was also too long, meaning neither size studs were long enough. 20 minutes with an angle grinder shortened the end of the pipe enough to get it to fit. As you can see, it's at a true 90 degs to the head, which being slightly inclined upwards means the pipe point too far down. So later I will regrind a slope onto the end of the pipe to make it more level. Noise is a little better (fruity but not too loud), power doesn't seem better or worse yet, but only ridden a mile so far. Weight is a lot better, and looks are SHIT LOADS better (well, I think so!). The baffle is welded in. It takes the form of a tube with the inside end shut, and holes drilled in the sides. I shall be drilling a small hole in the end to let more gas through.
Pipe cost £40, studs £4ish, and postage £6ish.
Experience running the exhaust revealed that as suspected the restrictive baffle is stiffling the engine, and it's actually lost a few mph.
Now on to modifying the exhaust!
Step 1) I tried drilling through the baffle, but even cheap ****** Stainless is too hard for normal HSS drills until you've got a pilot hole. Will have to find a special drill for hardened materials. In the end I ripped the baffle out, which involved pushing it down the pipe, and dremmeling the weld pips out. Then I cut off the end with the angle grinder. To fix it back in I did try solder, but no amount of fluxing and cleaning would let me tin the cheap stainless, so I had to drill it. An hour later after much faffing with various grinders, dremmels, diamond engraves, and old darts, I eventually made two 4mm holes suitable for a pop rivet under the pipe and in the baffle. I did try the pipe with no baffle - literally as restrictive as shouting down a traffic cone! Want your MSX to be louder than a Harley with Screaming Eagles? This will do it! Luckily the very gentle valve timing allows it to run with zero back pressure. With baffle fitted it's fine, a bit noisier, and it definitely revs as per normal now.
Step 2) Sorting the intake. I bought two air filters from ooracing with the exhaust, in the hope that at least one would work. BTW - the throttle body has a 38mm spigot.
The first was the PEX filter. http://www.ooracing.com/store/index.php?act=viewProd&productId=3720
BRILLIANT quality, with plenty of space to mount the intake sensor underneath. Unfortunately it didn't clear the frame. Any one want to buy a filter? £10 including p&p.
The failsafe option was the open stack. http://www.ooracing.com/store/index.php?act=viewProd&productId=3243
(The longest one). This was again lovely quality, shame about it just having a sticker on it instead of an etching or something.
This fitted nicely, but left me with no where to fit the sensor. I drilled a 9mm hole half way down for the sensor, and counter sunk it for the oring seal. I then drilled and tapped two M5x0.8 holes for a pair of stainless allen button bolt I had. These were fitted and marked flush with the inside of the stack. I removed then and trimmed to length, and refreshed the thread with a die. After a good clean I had a lovely stack complete with sensor. Assuming it's an intake temp sensor, being directly in the intake will cool it a little more and make the ECU inject a little extra fuel which will help compensate for the open intake and exhaust until the fuel injector arrives.
The last step was to cut up a plastic sieve to act as a mesh filter. I don't want it swallowing a chunk of grit etc. This was held on by a big jubilee clip. Not very neat, but works beautifully.
All this has enabled me to remove the entire air box assembly. Should help with cooling a bit. Does allow the panels to vibrate a bit as there's nothing to support them at the bottom now. But I might change to a different body set soon. In the mean time I have attached a set of cable ties to pull the panels in at the bottom. This has made them that little bit more rigid.
(for some reason it always rotate the picture of the intake. You can tell where horizontal is by looking at the bricks in the background!)
Following the exhaust and intake installation and modification over 1,000 trouble free miles have been done. The engine revs noticeably better, and higher rpm power is good, with plenty of over-rev. I suspect that the dyno chart would look similar to stock, maybe a little taller at the top, but that it would continue at a high plateau for longer before dropping.
OK, injector has now arrived and been fitted. http://www.rzracing.nl/webshop/honda-msx-high-perfarmance-fuel-injector-yuminashi/ It took a while to come after dispatch - post took about a week. To fit requires temporary removal of airbox and hence bodywork. If, like me, you no longer have the air box, fitting take about 3 minutes. Unplug the electrical cable. Then undo the two 10mm bolts on the mounting. Pull out old injector and mount. Pull old injector out of mount, and replace with new one. About 1 teaspoon of petrol dribbles out, no more, so have a little rag handy. Make sure new o-ring is on injector-end of injector. Refit injector and mount, reattach 10mm bolts. Reattach electrical cable. Take for a ride...
On first firing it up it idled VERY slow, like it was about to stall (900rpm). I took it up the road but past half throttle it began to choke. I made it up to about 47mph like this. A mile up the road I turned around, letting the engine idle again. Suddenly the idle improved back to normal. On the return leg, the engine revved cleanly. Infact, I hit 62mph in 3rd!
Results for a run up a level-ish piece of road, and then return. Very windy today.
Stock: 3rd gear - 57 out, 58 back. 4th gear - 56 out, 57 back.
Light-bore injector: 3rd gear - 58 out, 60 back. 4th gear - 58 out, 59 back.
So it makes a tiny improvement, but not much more than say, tucking in. Fitting very low bars may have same effect. My impression is that it revs better though. In which case on the motorway tomorrow I expect it will be significantly quicker than stock. I will let you know...
