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What did you do with your XS today?
- Thread starter logan
- Start date
Nope. The DOHC engine is just like the SOHC in that they are both 180 degree cranks. It may be due to weaker rings on my engine, or simply because I ride it hard. I solved the issue by venting the crankcase back into the carb inlets, just like the factory engineers wanted, and haven't been bothered by it since.
I had also made the mistake of gearing my bike lower when I was getting it ready to put on the road, based on what I'd read here. This resulted in the engine being "lugged" quite often, and requiring frequent downshifts to maintain speed on hills or to pass. I recently fixed that by installing a larger rear sprocket and couldn't be happier. By getting the revs up, the throttle response in every gear is greatly improved, and I rarely have to downshift. Now I cruise on the highway with the throttle barely open, and have lots available for passing. My top speed is "limited" to ~150kph (93 mph) as I'll hit the red line at that speed - not that I've verified this, the traffic on the highways around here average 120 kph (75 mph) which is comfortable for me.
I had also made the mistake of gearing my bike lower when I was getting it ready to put on the road, based on what I'd read here. This resulted in the engine being "lugged" quite often, and requiring frequent downshifts to maintain speed on hills or to pass. I recently fixed that by installing a larger rear sprocket and couldn't be happier. By getting the revs up, the throttle response in every gear is greatly improved, and I rarely have to downshift. Now I cruise on the highway with the throttle barely open, and have lots available for passing. My top speed is "limited" to ~150kph (93 mph) as I'll hit the red line at that speed - not that I've verified this, the traffic on the highways around here average 120 kph (75 mph) which is comfortable for me.
rafanomenon
XS400 Enthusiast
- Messages
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This weekend, I picked up my XS400 from my sheet metal guy. Custom gas tank and tail section. Insane work...
MrStubb
XS400 Addict
Dave I would have suggested some blow by but it hadn't come to me at the time. I wasn't sure if the cranks were the same configuration but now I do. Older cars used a road draft tube that vented under the car and was a reason for most older cars not rusting in the transmission tunnel area. (oil soaked) Long before they started to use the PCV system in use now. It was also the reason why many roads had a oil or grease strip in the middle of a lane at stop lights. I would think many bikes fell victim to this problem trying to stop on an oil slick.
Pork Chop
XS400 Junkie
Very classy.
Your bike is looking great - keep up the good work as i can't wait to see it finished.
Spad
XS400 Addict
Wow, and Wow, boy that is some piece of work...Spad
boy that is some piece of work...Spad
AnzacPaul
XS400 Enthusiast
Go the bike going in to have some baffles installed to in the exhaust to have it quietened down. it has twin full exhaust but literally sounds like its on headers, so I need to silence it a bit. Will report back tomorrow when I get it back and let you know how it went
Recreateme
XS400 Addict
Put some exhaust wrap on my headers and noticed something - the left side didn't burn in, the right side did, it's nice and brown, but the left side is still fresh and white...
Anyone know why that side would be a lower temp exhaust? (its not how i wrapped them, they look very consistent)
The left side is the side that had a lower compression reading of 125 i think (compared to the right sides 145ish i think) and the left side exhaust seems to drip a bit of fluid from the tail pipes. I think its just condensed exhaust gases not oil, or fuel.. its just like a water black gritty liquid. The other side doesn't do this.
Anyone know why that side would be a lower temp exhaust? (its not how i wrapped them, they look very consistent)
The left side is the side that had a lower compression reading of 125 i think (compared to the right sides 145ish i think) and the left side exhaust seems to drip a bit of fluid from the tail pipes. I think its just condensed exhaust gases not oil, or fuel.. its just like a water black gritty liquid. The other side doesn't do this.
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Sesty
H.E. Pennypacker
pretty sure compression in the cylinders needs to be with in 15-20psi of each other
Recreateme
XS400 Addict
my manual says the compression should be with 15% of each other, and both need to be over 90..
When i check it i got 125 on the left and 145 on the right (which is just about the end of the road of being 'good', but still good haha). Both are considered ok compression, and just around the 15%.. I am not going to rebuild my pistons, that is way to much work for me lol It runs well enough now, I am just wondering if that would reduce exhaust temps.
When i check it i got 125 on the left and 145 on the right (which is just about the end of the road of being 'good', but still good haha). Both are considered ok compression, and just around the 15%.. I am not going to rebuild my pistons, that is way to much work for me lol It runs well enough now, I am just wondering if that would reduce exhaust temps.
Sesty
H.E. Pennypacker
15% your right not psi!
i have not check my compression, but my left side does run cooler than the right and from putting my hands at the exhaust the left is coming out just a bit softer, so i would bet my compression is lower on that side for me as well
i have not check my compression, but my left side does run cooler than the right and from putting my hands at the exhaust the left is coming out just a bit softer, so i would bet my compression is lower on that side for me as well
How are your plugs looking? You may need to fine tune your mixture screws and sync the carbs in order for them to run at roughly equal temperatures.
Recreateme
XS400 Addict
My right side looks decent, left side does have some carbon on it.
I think i just need to play with the mix screws more carefully.
I plan on setting valves soon, so hopefully its just an issue with them that i can fix.
I think i just need to play with the mix screws more carefully.
I plan on setting valves soon, so hopefully its just an issue with them that i can fix.
MrStubb
XS400 Addict
Just got back from Fridley. Met with Wirehairs and bought the carb holders he had in the classifieds. What a nice guy hope he gets his Maxxum up & running. The holders from Mike's XS were for the sohc engines. Sure think he'd appreciate a set for an 82? Maxxum.
AnzacPaul
XS400 Enthusiast
Go the bike going in to have some baffles installed to in the exhaust to have it quietened down. it has twin full exhaust but literally sounds like its on headers, so I need to silence it a bit. Will report back tomorrow when I get it back and let you know how it went
So got the bike back, and it's much quieter. Has definitely affected the mid range performance it seems a bit sluggish between 4-6k rpm now, but it's liveable.
Of course, just when I thought the bike was all good, I get to the servo, and my petcock is dripping fuel everywhere
Seems to be one thing after another and tbh I'm almost done with it.
Jso123
XS400 Addict
My damn hid bulb went out again. At least a replacement is already enroute. Couldn't find a loose wire this time so I checked the fuse box . Main fuse seemed loose so I tried to squeeze the tabs tighter and "SNAP" time to buy a replacement box. I know there are some threads about fuse boxes... but got to sort them out. Crap crap crap (can I say that?)
You are correct the sohc does use 180* crank.
Sesty
H.E. Pennypacker
snapped my signal fuse the other day!
new box en-route
pretty cheap. they are on ebay too
http://www.delcity.net/store/ATC-&-ATO-4!way-Standard-Fuse-Block/p_795858
