'81 SRX bog

[Yam429]

I have an '81 SRX with Mikuni round slide carbs & a Comet 108 primary clutch. The problem I am having is I just took it out to Waconia for the vintage ride & all I could get out of it is 42mph at 5500rpm. This sled hasn't ran right since the day I bought it two years ago. I have cleaned the carbs and cleaned both the primary & secondary & still no difference in performance. Compression is 125 & 116. The sled starts up great & idles fine, engages at 4000rpm. I can't even get the track to break loose, it doesn't have enough power to do it. Once I get it up to 42mph & try to push the throttle any more the sled starts to bog like it's getting too much fuel or just not shifting out. This is frustrating any help would be greatly appreciated thanks, Reed

[Bob Vehring]

I went through some hard times also with mine. Much the same problems but not every time I ran it. I replaced everything, rebuilt the first engine, then finally replaced with a different one.
The problem turned out to be a wire in the loom that was broken inside but not through the outside colored plastic. That was a fun one to find. Hope your problem is easier to find

[vmax-540]

The compression sounds a little low for that sled. Also the clutch should engage at 5000 rpm's, That 440 engine didn't make any power until about 6000 rpm's then you better hold on. They didn't come with round slide carbs so who knows what they are from or jetted like. It also used a 102C Comet not a 108, so who knows how that is calibrated, the 102 used N-1 weights and the Purple spring # 207888 with 106 LBS - 226 LBS, start from there but remember the 108 calibrates a little different then the 102 so you may need a stiffer spring. Also make sure the secondary is set for 240 degree of twist it needs to run between 9000, and 9250 rpms. This should be a start for you hope it helps you out...

[Vmax540]

Reed, sounds to me like Jeffery (vmax-540) hit the nail on the head on all accounts. Way to low engagement and the 108's can be made to work but, as you can read in the clutching posts here in the forum there are needed adjustments.

[Yam429]

Perfect thanks for the advice guys I will look into it.