| Author | Message | ||
     Buell82 |
I finally have gotten my bike back together from a total top end rebuild. My rear cylinder had a bad detonation and melted my piston. So, now that I have my bike running again, what things can I do to make sure this wont happen again? I still have no idea exactly why it happened first time?!? I dont believe it is running lean. Any help and info you guys can give me will be greatly appreciated. | ||
| Phat_j |
get it tuned................ | ||
| Tattoodnscrewd |
get it tuned................ +++++++1 Best thing to do after a fresh build - schedule some dyno time to get it properly tuned ... (might gain more power as well - I gained 6-7hp after a good dyno-tune) | ||
| Buell82 |
Well obviously get it tuned...just am afraid of doing anything to the bike. Dyno for instance is hard on the bike, right? I would hate to be running my bike like that and have it detonate again to destruction.:-( Are there any specific things I should look at? How can I make sure it is not running too lean? What jets should I have in the carb with after market exhaust? Someone told me I should look at the VOES switch? Thanks, Mike | ||
| Silas_clone |
Along these lines; 1. Does the Voes switch function as a simple on-off? 2. Would shimming the needle of a CV carb evoke all sorts of other considerations/gremlins? My little pony seems to ping a bit during mid-range running with what seems to me to be light loads. I lost 25 lbs but still weigh 280, so maybe "light loads" is wishful thinking. Plugs look grayish too. Plenty of power when I give it a goose [accelerator pump?] or if I drop a gear. High speed [100mph] seems good, no acceleration if I back off a bit from full throttle, so I am thinking shims to add a bit of gas to mid-range running. Is this faulty thinking? | ||
| Tattoodnscrewd |
How can I make sure it is not running too lean? What jets should I have in the carb with after market exhaust? Someone told me I should look at the VOES switch? Those are all things a *good* dyno guy can and should be doing ... They will do a couple pulls and know if you are lean at a given point, they will know what needles are needed, shimming needed, all that you mentioned and then some - if you have a selectable curve ignition they will know what curve is needed - often times most things will be noticed after one pull ... I was even told after my S1 build when I first took it in that they couldn't do it - intake leak .. when I fixed it and went back in - one pull and he knew I was running extremely rich .. specifically right off throttle - that told him what direction to go and what to correct .. They should be able to see/notice anything going on .. take it to a reputable place and do a true dyno-tune on it .. Before you go in maybe check the static timing to make sure you are on point .. then get it in .. | ||
| Ryker77 |
"Engines that are detonating will tend to overheat, because the boundary layer of gas gets interrupted against the cylinder head and heat gets transferred from the combustion chamber into the cylinder head and into the coolant. So it starts to overheat. The more it overheats, the hotter the engine, the hotter the end gas, the more it wants to detonate, the more it wants to overheat. It's a snowball effect. That's why an overheating engine wants to detonate and that's why engine detonation tends to cause overheating" proper tune including carb and timing, oil cooler, larger oil filter, proper sparkplugs. For extra saftey octane booster - Lucas Offroad is like 9.00 per bottle but works on 5 tanks of gas. | ||
| Bad_karma |
Mike As said above there is no substitute for proper tuning. But if you like myself want easy access and control of advance and ignition functions look at crane or any of the other stand alone ignition that give you access to these parameters. In addition eliminating the troublesome wiring in a hostile environment. Joe (Message edited by bad_karma on August 05, 2007) | ||
| Rick_a |
Make sure you are using 10R12 or equivalent heat range spark plugs. Dyno tuning puts a minimal load on a motor. The worst thing you could do is tune a bad running motor by trial and error. Unless your engine has been modified in ways such as significantly altered compression ratios, combustion chamber design, porting, cam profiles, etc, the stock ignition works very well. | ||
| Bookyoh |
Silas: My recollection is that the VOES is an on/off and changes the ignition advance at a pre-set manifold vacuum level. The VOES setting can be adjusted. Shimming the needle is a way to change the mid range fuel mixture. I put a "6048" washer in my 2000 M2 7 years ago to slightly richen that mid range and reduce the part load pinging. Mark | ||
| Silas_clone |
Mark, is a "6048" a part number? I read about .050" shims. They gotta be brass? | ||
| Bookyoh |
The 6048 seems to be a Harley part number. I have bought a few of them over the years. They cost about 50 cents and I'd guess they probably are around 0.050". They looked like steel to me. Mark | ||
| Focusman |
Has anyone had a good dyno tuning experience in the metro Detroit area? | ||
| Cyclonecharlie |
If you procrastinate on the tuning suggestions(all good) at least keep COLD plugs in the motor till you get around to tuning it on a dyno....  Charlie |
