Engine mods

adamax · Sep 12, 2023

Hello folks, it has been a while I was neither riding nor wrenching.. I am looking for some slight engine mods that have been posted by a fellow member but I could not find on the forum, related to 1300cc conversion and advancing the valves.. if anyone could help with these details or any other mods advice.. TIA

MaxMidnight · Sep 13, 2023

IMO you should also be asking 'How much did it cost?' and 'What benefit in performance did it yield?'

Stephan · Sep 14, 2023

The best performance upgrade for a gen. 1 is get a gen. 2!

MadMark · Sep 14, 2023

adamax said:
Hello folks, it has been a while I was neither riding nor wrenching.. I am looking for some slight engine mods that have been posted by a fellow member but I could not find on the forum, related to 1300cc conversion and advancing the valves.. if anyone could help with these details or any other mods advice.. TIA

A 1300cc conversion I don't think is a slight engine mod. I don't think it's worth it, unless you need to rebuild the motor. Then it depends on your budget. Biggest bang for the buck is a proper exhaust an jet kit. Which you'll need anyways.

one2dmax · Sep 14, 2023

The venture 1300 (86-93) is a great option to get about 10% power increase from bore size change only. You reuse your Vmax heads/cams and vboost/carb stuff (and move over a few parts like the shift shaft, oil level sending unit, nuetral switch, and PCV breather assembly). Same compression. I would swap over your flywheel as well. Trans is ok though it has the same basic design that was recalled in the 85 Vmax so at some point that may need changed. Slight may be a loose term as you can generally get the engines at a decent price but you have a fair amount of work to do.

juhhol · Sep 16, 2023

Hello, I've just a month ago installed to venture -85 venture 87 1300 engine with V max full power heads and high pressure OZ pistons. now it is 1340 cc and works nice with venture origin carbs and origin exhaust ! .she leaves very fast from taffic lights to be venture travelling type bike . there is coming uppdate with 40 mm mikuni carb kit and vmax race prog .ignition . super traps are also to be installed. fly wheel may need to be changed is vmax and venture has different advance.

juhhol · Sep 16, 2023

ok , folks . I need to change the radiator to larger because the engines coolant heat rised too high. now engine temp is good and low enought and it is possibly to drive at 30 C ambients.

adamax · Sep 22, 2023

Thank you folks for your valuable input. I do have already a 2004 with Marks exhaust and Sean's air filter with jet kit installed, it rides like a bat out of hell. I am technically inclined, retired and have 2 spare engines with some bits and pieces, one engine I am willing to bore to accomodate a set of 1300 venture's pistons, and another engine that I bored and re-sleeved with venture's liners, then bored them out to accomodate wiseco big bore forged pistons to make about 1400cc of displacement. I remember reading a comment about changing the camshaft timing, but I could not find it. Any help, opinion, suggestion is well appreciated.. TIA

Fire-medic · Sep 22, 2023

I expect Sean Morley will step in with the info you seek. I suspect there are choices you can make regarding camshafts, for more lift for instance. I believe that the OEM cams are added-to for the lobes, machined for desired lift, and then undergo some type of hardening.

one2dmax · Sep 23, 2023

To change the cam timing you must modify your sprockets (slot them) and then time then in. I've not bothered with that step in the process for most engines. When you go with larger cams they do have to weld them up and regrind them to the new desired profile. You do have to make sure your pistons are clearances for it and if large enough you have to change the shim type to move them under the bucket instead of on top (soo valve adjustments are tougher).