Why the decompression circuit?

[mikebet45]

I have owned a 1500 Goldwing and three V-twins -- 1100 Virago, Harley Electra Glide and a Vulcan 1500 -- and none of them had (or apparently needed) decompression valves at starting. So why does the 1400 Intruder need it? 9.3:1 compression ratio is not exactly sky-high. I know that Suzukis are generally reputed to have weak starters -- the Virago's sounded like a tin can full of marbles -- but it's kind of strange that they didn't put sturdier starters on these bikes if they anticipated a problem rather than a solenoid, network of cables and the added complexity of release valves. And the system is apparently unnecessary anyway. Mine is not working as I view it with the chrome valve cover off (no cable movement at all even after lubing and adjustment) but the bike starts OK. But just in case I do need to do something in the future what's the easiest way to access the cleverly hidden solenoid?

[sgtcall]

I have owned a 1500 Goldwing and three V-twins -- 1100 Virago, Harley Electra Glide and a Vulcan 1500 -- and none of them had (or apparently needed) decompression valves at starting. So why does the 1400 Intruder need it? 9.3:1 compression ratio is not exactly sky-high. I know that Suzukis are generally reputed to have weak starters -- the Virago's sounded like a tin can full of marbles -- but it's kind of strange that they didn't put sturdier starters on these bikes if they anticipated a problem rather than a solenoid, network of cables and the added complexity of release valves. And the system is apparently unnecessary anyway. Mine is not working as I view it with the chrome valve cover off (no cable movement at all even after lubing and adjustment) but the bike starts OK. But just in case I do need to do something in the future what's the easiest way to access the cleverly hidden solenoid?

I can't answer any real questions but I sure someone will chime in. In the mean time you can find the service manual here viewtopic.php?f=19&t=14168 and in the 'other information' folder you can find more on the decomp adjustment. Here https://www.dropbox.com/s/slouooavobjdx ... t.pdf?dl=0

[Herb]

If you have the evap cannister you have to pull it first. might be easier to pull the damn engine... first try lubing the cables using a spray hose to wash the grit and grime out of it and spraying it good with a penatrationg oil, like PB Blaster.

If it is starting good for your use, maybe leave the thing alone.

As for the reason for it: Smaller (cheaper) starter, smaller (cheaper) battery, easier cold starts, large amount of rotating weight are the reasons given.

I think the first 2 are the main reasons but I don't see how they saved any money or weight with the added weight and cost of all the extra components. I have never really understood the reasoning either.

BTW, when Honda first came out with electric starters on the 250 and 305s, early 60's, they recommended that the first start of the day be done with the kick starter. I am not sure if they recommended that for the 150s

[hillsy v2]

It's not so much the starter motors or circuitry that are prone to fail - but the starter clutches by their very design are a weak point when it comes to big CC twins. Virago's as mentioned are notorious for destroying starter clutches and even Suzuki's own Dr BIG was another culprit (750 / 800cc single). In normal operation they are fine but if there is a backfire / kickback then the starter clutches can get damaged.

The decomp was probably the easiest way to ensure the starter clutches would be OK - as well as just generally helping all round with less stress on the system.