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Post by brazenc5 on Apr 2, 2008 1:52:54 GMT -5
Hi there, I like the look of a removed airbox, and was wondering if I install an aftermarket exhaust and removed the air box, but kept the original carb, will it just need tweaking of the mixture screw, or will i have to upgrade the carb or jets to compensate for the changes? I tried the search function before posting the question, but didn't find any definitive info. Also I plan to take apart the top end of the engine for inspection. What is the popular method or products to clean/polish the exterior of the cylinder head assembly? I pulled the whole engine out, and am excited to start on this rebuild. Complete novice here, and hoping to learn from the resident members on this forum.  chris 1980 SR500 |
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Post by andy on Apr 2, 2008 5:57:25 GMT -5
Hi Chris,I've carried out both of the above,like you say the carb should only want re-tuning of the mixture,if you are not sure invest a bit of money on some dyno time to get it spot on although i dont think you will have a problem.When dismantling and stripping the top end put your cylinder head,cam cover,tappet covers and barrel in your dishwasher with 2 tablets.This is an old trick i learnt of a mate whose been in the trade umpteen years and works great,repeat the process pending on how gunged up they are.After i did mine i got some smooth hammerite spray can paint and gave the barrel a couple of coats,it looked great with the head left natural.depending on how good your looking to get it have a look at stewross's
project bike,he has gone for fine beadblasting and that is the ultimate finish,they come up better than new but you MUST mask/bung-up all the holes to stop getting glass beads getting in the wrong places,apparently this is quite cheap if you have got that facility nearby.E-mail me if you want some pics of my bike to give you some idea of the results.Regarding the re-build,just take your time and methodically work through it with the aid of the workshop manual [i've got the haynes version].Hope this helps.
Andy
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Post by modrocker on Apr 2, 2008 7:25:19 GMT -5
Certainly there is much more experience on this forum but I do have a few comments: My '79 has a stock head pipe with a aftermarket muffler; I removed the airbox and replaced it with a clamp-on filter. Since I had to rebuild the carb (due to neglect as much as anything) I followed the many-mentioned "Minton Mods" www.siue.edu/~rsutton/SR/carbmod.htmas a guide line for jetting changes and how to procede. Having cut my teeth on Amal carbs, the Mikuni is more complex but not that different. I did have to tinker and kick quite a while to get the bike started and running (on Monday, March 31, for the first time in at least a decade) but once it warmed up, it ran great. I know I still need to fine tune the whole set up but it runs better that it did last week... HTH, Kevin |
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Post by brazenc5 on Apr 2, 2008 19:33:40 GMT -5
Hi Andy and Kevin...thanks for the replies!!
I'll have to give the diswasher and tablets a try, and i'll email you to check out the pics of your engine.
Kevin that link has a lot of great info..i'm printing it out now to read over and reference it on the work table.
Originally I wanted to chrome the engine, but after reading up on here, it doesn't sound like a good idea. Then I wondered if its possible to polish the top end to a mirror like finish, but i haven't seen any on the boards, so I dont know if its possible.
thanks again!
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Post by colinjay on Apr 2, 2008 22:56:18 GMT -5
The dishwasher will do a fairly good job, just don't get caught by the "boss" of the house, it for this reason that I have a dishwasher in my shed/workshop.
Chroming of engines is not recommended as it holds the heat into the engine and can cause the engine to overheat, of couse this is not a worry for the builders of custom choppers and show bikes.
Polishing an engine to a mirror finish has similar effets to chroming, although not nearly as bad, and you can actually ride the bike unlike chroming. You still would not want to ride the bike too hard or race it.
Polishing the head crankcases, outer engine covers and rocker cover is not overly difficult, but is very time consuming even if you have a reasonable good polishing rig. I use a home made polisher with a 1hp electric motor driving 2 x 10" polishing mops. and use a variety of different polishing rouges. To bring an average condition clutch cover up to a mirror finish takes about an hour or so. I have never tried to do a cylinder head, but as the standard finish of the head is "as cast" it would take an awful lot of work and would require smoothing out with various grades of wet & dry sandpaper before progressing to final polishing with collection of small polishing mops. I don't know how you would get to the area between the fins if you wanted to go that far.
Most of the guys (myself included) just have the head and cylinder Hydroblasted/vapour blasted which is a method of glassbead blasting with the beads suspended in water. This give a very good finish and does not seam to get as dirt as ordinary glass bead blasting.
CJ
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